diff --git a/test/common.py b/test/common.py
index d7c30e645109..1c84c8e652b5 100644
--- a/test/common.py
+++ b/test/common.py
@@ -555,6 +555,17 @@ def force_delete_contents(dirname):
   utils.delete_contents(dirname)
 
 
+def find_browser_test_file(filename):
+  """Looks for files in test/browser and then in test/
+  """
+  if not os.path.exists(filename):
+    fullname = test_file('browser', filename)
+    if not os.path.exists(fullname):
+      fullname = test_file(filename)
+    filename = fullname
+  return filename
+
+
 def parameterized(parameters):
   """
   Mark a test as parameterized.
@@ -2010,11 +2021,12 @@ def run_browser(self, html_file, expected=None, message=None, timeout=None, extr
 
   # @manually_trigger If set, we do not assume we should run the reftest when main() is done.
   #                   Instead, call doReftest() in JS yourself at the right time.
-  def reftest(self, expected, manually_trigger=False):
+  def make_reftest(self, expected, manually_trigger=False):
     # make sure the pngs used here have no color correction, using e.g.
     #   pngcrush -rem gAMA -rem cHRM -rem iCCP -rem sRGB infile outfile
     basename = os.path.basename(expected)
-    shutil.copyfile(expected, self.in_dir(basename))
+    if os.path.abspath(os.path.dirname(expected)) != self.get_dir():
+      shutil.copyfile(expected, self.in_dir(basename))
     reporting = read_file(test_file('browser_reporting.js'))
     create_file('reftest.js', '''
       function doReftest() {
@@ -2141,8 +2153,15 @@ def compile_btest(self, filename, args, reporting=Reporting.FULL):
       filename = test_file(filename)
     self.run_process([compiler_for(filename), filename] + self.get_emcc_args() + args)
 
+  def reftest(self, filename, reference, *args, **kwargs):
+    """Special case of `btest` that uses reference image
+    """
+    assert 'reference' not in kwargs
+    kwargs['reference'] = reference
+    return self.btest(filename, *args, **kwargs)
+
   def btest_exit(self, filename, assert_returncode=0, *args, **kwargs):
-    """Special case of btest that reports its result solely via exiting
+    """Special case of `btest` that reports its result solely via exiting
     with a given result code.
 
     In this case we set EXIT_RUNTIME and we don't need to provide the
@@ -2167,15 +2186,11 @@ def btest(self, filename, expected=None, reference=None,
       args = []
     original_args = args
     args = args.copy()
-    if not os.path.exists(filename):
-      fullname = test_file('browser', filename)
-      if not os.path.exists(fullname):
-        fullname = test_file(filename)
-      filename = fullname
+    filename = find_browser_test_file(filename)
     if reference:
-      self.reference = reference
+      reference = find_browser_test_file(reference)
       expected = [str(i) for i in range(0, reference_slack + 1)]
-      self.reftest(test_file(reference), manually_trigger=manually_trigger_reftest)
+      self.make_reftest(reference, manually_trigger=manually_trigger_reftest)
       if not manual_reference:
         args += ['--pre-js', 'reftest.js', '-sGL_TESTING']
     else:
diff --git a/test/test_browser.py b/test/test_browser.py
index cda3dce3a432..34c8aae95956 100644
--- a/test/test_browser.py
+++ b/test/test_browser.py
@@ -249,14 +249,14 @@ def test_sdl1_in_emscripten_nonstrict_mode(self):
       self.skipTest('This test requires being run in non-strict mode (EMCC_STRICT env. variable unset)')
     # TODO: This test is verifying behavior that will be deprecated at some point in the future, remove this test once
     # system JS libraries are no longer automatically linked to anymore.
-    self.btest('hello_world_sdl.cpp', reference='htmltest.png')
+    self.reftest('hello_world_sdl.cpp', 'htmltest.png')
 
   def test_sdl1(self):
-    self.btest('hello_world_sdl.cpp', reference='htmltest.png', args=['-lSDL', '-lGL'])
-    self.btest('hello_world_sdl.cpp', reference='htmltest.png', args=['-sUSE_SDL', '-lGL']) # is the default anyhow
+    self.reftest('hello_world_sdl.cpp', 'htmltest.png', args=['-lSDL', '-lGL'])
+    self.reftest('hello_world_sdl.cpp', 'htmltest.png', args=['-sUSE_SDL', '-lGL']) # is the default anyhow
 
   def test_sdl1_es6(self):
-    self.btest('hello_world_sdl.cpp', reference='htmltest.png', args=['-sUSE_SDL', '-lGL', '-sEXPORT_ES6'])
+    self.reftest('hello_world_sdl.cpp', 'htmltest.png', args=['-sUSE_SDL', '-lGL', '-sEXPORT_ES6'])
 
   # Deliberately named as test_zzz_* to make this test the last one
   # as this test may take the focus away from the main test window
@@ -767,7 +767,7 @@ def test_sdl_swsurface(self):
 
   def test_sdl_surface_lock_opts(self):
     # Test Emscripten-specific extensions to optimize SDL_LockSurface and SDL_UnlockSurface.
-    self.btest('hello_world_sdl.cpp', reference='htmltest.png', args=['-DTEST_SDL_LOCK_OPTS', '-lSDL', '-lGL'])
+    self.reftest('hello_world_sdl.cpp', 'htmltest.png', args=['-DTEST_SDL_LOCK_OPTS', '-lSDL', '-lGL'])
 
   @parameterized({
     '': ([],),
@@ -801,7 +801,7 @@ def test_sdl_image_jpeg(self):
   def test_sdl_image_prepare(self):
     # load an image file, get pixel data.
     shutil.copyfile(test_file('screenshot.jpg'), 'screenshot.not')
-    self.btest('test_sdl_image_prepare.c', reference='screenshot.jpg', args=['--preload-file', 'screenshot.not', '-lSDL', '-lGL'], also_proxied=True, manually_trigger_reftest=True)
+    self.reftest('test_sdl_image_prepare.c', 'screenshot.jpg', args=['--preload-file', 'screenshot.not', '-lSDL', '-lGL'], also_proxied=True, manually_trigger_reftest=True)
 
   @parameterized({
     '': ([],),
@@ -813,42 +813,42 @@ def test_sdl_image_prepare(self):
   def test_sdl_image_prepare_data(self, args):
     # load an image file, get pixel data.
     shutil.copyfile(test_file('screenshot.jpg'), 'screenshot.not')
-    self.btest('test_sdl_image_prepare_data.c', reference='screenshot.jpg', args=['--preload-file', 'screenshot.not', '-lSDL', '-lGL'] + args, manually_trigger_reftest=True)
+    self.reftest('test_sdl_image_prepare_data.c', 'screenshot.jpg', args=['--preload-file', 'screenshot.not', '-lSDL', '-lGL'] + args, manually_trigger_reftest=True)
 
   def test_sdl_image_must_prepare(self):
     # load an image file, get pixel data.
     shutil.copyfile(test_file('screenshot.jpg'), 'screenshot.jpg')
-    self.btest('test_sdl_image_must_prepare.c', reference='screenshot.jpg', args=['--preload-file', 'screenshot.jpg', '-lSDL', '-lGL'], manually_trigger_reftest=True)
+    self.reftest('test_sdl_image_must_prepare.c', 'screenshot.jpg', args=['--preload-file', 'screenshot.jpg', '-lSDL', '-lGL'], manually_trigger_reftest=True)
 
   def test_sdl_stb_image(self):
     # load an image file, get pixel data.
     shutil.copyfile(test_file('screenshot.jpg'), 'screenshot.not')
-    self.btest('test_sdl_stb_image.c', reference='screenshot.jpg', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_stb_image.c', 'screenshot.jpg', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
 
   def test_sdl_stb_image_bpp(self):
     # load grayscale image without alpha
     shutil.copyfile(test_file('browser/test_sdl-stb-bpp1.png'), 'screenshot.not')
-    self.btest('test_sdl_stb_image.c', reference='browser/test_sdl-stb-bpp1.png', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_stb_image.c', 'test_sdl-stb-bpp1.png', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
 
     # load grayscale image with alpha
     self.clear()
     shutil.copyfile(test_file('browser/test_sdl-stb-bpp2.png'), 'screenshot.not')
-    self.btest('test_sdl_stb_image.c', reference='browser/test_sdl-stb-bpp2.png', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_stb_image.c', 'test_sdl-stb-bpp2.png', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
 
     # load RGB image
     self.clear()
     shutil.copyfile(test_file('browser/test_sdl-stb-bpp3.png'), 'screenshot.not')
-    self.btest('test_sdl_stb_image.c', reference='browser/test_sdl-stb-bpp3.png', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_stb_image.c', 'test_sdl-stb-bpp3.png', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
 
     # load RGBA image
     self.clear()
     shutil.copyfile(test_file('browser/test_sdl-stb-bpp4.png'), 'screenshot.not')
-    self.btest('test_sdl_stb_image.c', reference='browser/test_sdl-stb-bpp4.png', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_stb_image.c', 'test_sdl-stb-bpp4.png', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
 
   def test_sdl_stb_image_data(self):
     # load an image file, get pixel data.
     shutil.copyfile(test_file('screenshot.jpg'), 'screenshot.not')
-    self.btest('test_sdl_stb_image_data.c', reference='screenshot.jpg', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_stb_image_data.c', 'screenshot.jpg', args=['-sSTB_IMAGE', '--preload-file', 'screenshot.not', '-lSDL', '-lGL'])
 
   def test_sdl_stb_image_cleanup(self):
     shutil.copyfile(test_file('screenshot.jpg'), 'screenshot.not')
@@ -882,14 +882,14 @@ def post_manual_reftest(self):
 
   def test_sdl_canvas_proxy(self):
     create_file('data.txt', 'datum')
-    self.btest('test_sdl_canvas_proxy.c', reference='browser/test_sdl_canvas_proxy.png', args=['--proxy-to-worker', '--preload-file', 'data.txt', '-lSDL', '-lGL'], manual_reference=True, post_build=self.post_manual_reftest)
+    self.reftest('test_sdl_canvas_proxy.c', 'test_sdl_canvas_proxy.png', args=['--proxy-to-worker', '--preload-file', 'data.txt', '-lSDL', '-lGL'], manual_reference=True, post_build=self.post_manual_reftest)
 
   @requires_graphics_hardware
   def test_glgears_proxy_jstarget(self):
     # test .js target with --proxy-worker; emits 2 js files, client and worker
     self.compile_btest('hello_world_gles_proxy.c', ['-o', 'test.js', '--proxy-to-worker', '-sGL_TESTING', '-lGL', '-lglut'])
     shell_with_script('shell_minimal.html', 'test.html', '<script src="test.js"></script>')
-    self.reftest(test_file('gears.png'))
+    self.make_reftest(test_file('gears.png'))
     self.post_manual_reftest()
     self.run_browser('test.html', '/report_result?0')
 
@@ -898,8 +898,8 @@ def test_sdl_canvas_alpha(self):
     # See https://github.com/emscripten-core/emscripten/issues/4069.
     create_file('flag_0.js', "Module['arguments'] = ['-0'];")
 
-    self.btest('test_sdl_canvas_alpha.c', args=['-lSDL', '-lGL'], reference='browser/test_sdl_canvas_alpha.png', reference_slack=12)
-    self.btest('test_sdl_canvas_alpha.c', args=['--pre-js', 'flag_0.js', '-lSDL', '-lGL'], reference='browser/test_sdl_canvas_alpha_flag_0.png', reference_slack=12)
+    self.reftest('test_sdl_canvas_alpha.c', 'test_sdl_canvas_alpha.png', args=['-lSDL', '-lGL'], reference_slack=12)
+    self.reftest('test_sdl_canvas_alpha.c', 'test_sdl_canvas_alpha_flag_0.png', args=['--pre-js', 'flag_0.js', '-lSDL', '-lGL'], reference_slack=12)
 
   @parameterized({
     '': ([],),
@@ -1559,63 +1559,63 @@ def test_sdl_gl_mapbuffers(self):
   @requires_graphics_hardware
   def test_sdl_ogl(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_ogl.c', reference='screenshot-gray-purple.png', reference_slack=1,
-               args=['-O2', '--minify=0', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_ogl.c', 'screenshot-gray-purple.png', reference_slack=1,
+                 args=['-O2', '--minify=0', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_sdl_ogl_regal(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_ogl.c', reference='screenshot-gray-purple.png', reference_slack=1,
-               args=['-O2', '--minify=0', '--preload-file', 'screenshot.png', '-sUSE_REGAL', '-DUSE_REGAL', '--use-preload-plugins', '-lSDL', '-lGL', '-lc++', '-lc++abi'])
+    self.reftest('test_sdl_ogl.c', 'screenshot-gray-purple.png', reference_slack=1,
+                 args=['-O2', '--minify=0', '--preload-file', 'screenshot.png', '-sUSE_REGAL', '-DUSE_REGAL', '--use-preload-plugins', '-lSDL', '-lGL', '-lc++', '-lc++abi'])
 
   @requires_graphics_hardware
   def test_sdl_ogl_defaultmatrixmode(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_ogl_defaultMatrixMode.c', reference='screenshot-gray-purple.png', reference_slack=1,
-               args=['--minify=0', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_ogl_defaultMatrixMode.c', 'screenshot-gray-purple.png', reference_slack=1,
+                 args=['--minify=0', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_sdl_ogl_p(self):
     # Immediate mode with pointers
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_ogl_p.c', reference='screenshot-gray.png', reference_slack=1,
-               args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_ogl_p.c', 'screenshot-gray.png', reference_slack=1,
+                 args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_sdl_ogl_proc_alias(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_ogl_proc_alias.c', reference='screenshot-gray-purple.png', reference_slack=1,
-               args=['-O2', '-g2', '-sINLINING_LIMIT', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-sGL_ENABLE_GET_PROC_ADDRESS', '--use-preload-plugins', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_ogl_proc_alias.c', 'screenshot-gray-purple.png', reference_slack=1,
+                 args=['-O2', '-g2', '-sINLINING_LIMIT', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-sGL_ENABLE_GET_PROC_ADDRESS', '--use-preload-plugins', '-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_sdl_fog_simple(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_fog_simple.c', reference='screenshot-fog-simple.png',
-               args=['-O2', '--minify=0', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_fog_simple.c', 'screenshot-fog-simple.png',
+                 args=['-O2', '--minify=0', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_sdl_fog_negative(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_fog_negative.c', reference='screenshot-fog-negative.png',
-               args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_fog_negative.c', 'screenshot-fog-negative.png',
+                 args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_sdl_fog_density(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_fog_density.c', reference='screenshot-fog-density.png',
-               args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_fog_density.c', 'screenshot-fog-density.png',
+                 args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_sdl_fog_exp2(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_fog_exp2.c', reference='screenshot-fog-exp2.png',
-               args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_fog_exp2.c', 'screenshot-fog-exp2.png',
+                 args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_sdl_fog_linear(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_fog_linear.c', reference='screenshot-fog-linear.png', reference_slack=1,
-               args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_fog_linear.c', 'screenshot-fog-linear.png', reference_slack=1,
+                 args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins', '-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_glfw(self):
@@ -1785,8 +1785,8 @@ def test_chunked_synchronous_xhr(self):
 
   @requires_graphics_hardware
   def test_glgears(self, extra_args=[]):  # noqa
-    self.btest('hello_world_gles.c', reference='gears.png', reference_slack=3,
-               args=['-DHAVE_BUILTIN_SINCOS', '-lGL', '-lglut'] + extra_args)
+    self.reftest('hello_world_gles.c', 'gears.png', reference_slack=3,
+                 args=['-DHAVE_BUILTIN_SINCOS', '-lGL', '-lglut'] + extra_args)
 
   @requires_graphics_hardware
   @requires_threads
@@ -1826,8 +1826,8 @@ def test_fulles2_sdlproc(self):
 
   @requires_graphics_hardware
   def test_glgears_deriv(self):
-    self.btest('hello_world_gles_deriv.c', reference='gears.png', reference_slack=2,
-               args=['-DHAVE_BUILTIN_SINCOS', '-lGL', '-lglut'])
+    self.reftest('hello_world_gles_deriv.c', 'gears.png', reference_slack=2,
+                 args=['-DHAVE_BUILTIN_SINCOS', '-lGL', '-lglut'])
     assert 'gl-matrix' not in read_file('test.html'), 'Should not include glMatrix when not needed'
 
   @requires_graphics_hardware
@@ -1859,9 +1859,7 @@ def book_path(path):
         shutil.copyfile(book_path('Chapter_13/ParticleSystem/smoke.tga'), 'smoke.tga')
         args += ['--preload-file', 'smoke.tga', '-O2'] # test optimizations and closure here as well for more coverage
 
-      self.btest(program,
-                 reference=book_path(basename.replace('.o', '.png')),
-                 args=args)
+      self.reftest(program, book_path(basename.replace('.o', '.png')), args=args)
 
   @requires_graphics_hardware
   @parameterized({
@@ -1884,19 +1882,18 @@ def test_gles2_emulation(self, args):
       ('third_party/glbook/Chapter_13/ParticleSystem/ParticleSystem_orig.c', 'third_party/glbook/CH13_ParticleSystem.png'),
     ]:
       print(source)
-      self.btest(source,
-                 reference=test_file(reference),
-                 args=['-I' + test_file('third_party/glbook/Common'),
-                       test_file('third_party/glbook/Common/esUtil.c'),
-                       test_file('third_party/glbook/Common/esShader.c'),
-                       test_file('third_party/glbook/Common/esShapes.c'),
-                       test_file('third_party/glbook/Common/esTransform.c'),
-                       '-lGL', '-lEGL', '-lX11',
-                       '--preload-file', 'basemap.tga', '--preload-file', 'lightmap.tga', '--preload-file', 'smoke.tga'] + args)
+      self.reftest(source, reference,
+                   args=['-I' + test_file('third_party/glbook/Common'),
+                         test_file('third_party/glbook/Common/esUtil.c'),
+                         test_file('third_party/glbook/Common/esShader.c'),
+                         test_file('third_party/glbook/Common/esShapes.c'),
+                         test_file('third_party/glbook/Common/esTransform.c'),
+                         '-lGL', '-lEGL', '-lX11',
+                         '--preload-file', 'basemap.tga', '--preload-file', 'lightmap.tga', '--preload-file', 'smoke.tga'] + args)
 
   @requires_graphics_hardware
   def test_clientside_vertex_arrays_es3(self):
-    self.btest('clientside_vertex_arrays_es3.c', reference='gl_triangle.png', args=['-sFULL_ES3', '-sUSE_GLFW=3', '-lglfw', '-lGLESv2'])
+    self.reftest('clientside_vertex_arrays_es3.c', 'gl_triangle.png', args=['-sFULL_ES3', '-sUSE_GLFW=3', '-lglfw', '-lGLESv2'])
 
   def test_emscripten_api(self):
     self.btest_exit('emscripten_api_browser.c', args=['-sEXPORTED_FUNCTIONS=_main,_third', '-lSDL'])
@@ -2005,7 +2002,7 @@ def test_glframebufferattachmentinfo(self):
   @no_wasm64('TODO: LEGACY_GL_EMULATION + wasm64')
   @requires_graphics_hardware
   def test_sdl_glshader(self):
-    self.btest('test_sdl_glshader.c', reference='browser/test_sdl_glshader.png', args=['-O2', '--closure=1', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-sGL_ENABLE_GET_PROC_ADDRESS'])
+    self.reftest('test_sdl_glshader.c', 'test_sdl_glshader.png', args=['-O2', '--closure=1', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-sGL_ENABLE_GET_PROC_ADDRESS'])
 
   @no_wasm64('TODO: LEGACY_GL_EMULATION + wasm64')
   @requires_graphics_hardware
@@ -2029,43 +2026,43 @@ def test_gl_textures(self, args):
   def test_gl_ps(self):
     # pointers and a shader
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('gl_ps.c', reference='gl_ps.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'], reference_slack=1)
+    self.reftest('gl_ps.c', 'gl_ps.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'], reference_slack=1)
 
   @requires_graphics_hardware
   def test_gl_ps_packed(self):
     # packed data that needs to be strided
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('gl_ps_packed.c', reference='gl_ps.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'], reference_slack=1)
+    self.reftest('gl_ps_packed.c', 'gl_ps.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'], reference_slack=1)
 
   @requires_graphics_hardware
   def test_gl_ps_strides(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('gl_ps_strides.c', reference='gl_ps_strides.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'])
+    self.reftest('gl_ps_strides.c', 'gl_ps_strides.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'])
 
   @requires_graphics_hardware
   def test_gl_ps_worker(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('gl_ps_worker.c', reference='gl_ps.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'], reference_slack=1, also_proxied=True)
+    self.reftest('gl_ps_worker.c', 'gl_ps.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'], reference_slack=1, also_proxied=True)
 
   @requires_graphics_hardware
   def test_gl_renderers(self):
-    self.btest('gl_renderers.c', reference='gl_renderers.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('gl_renderers.c', 'gl_renderers.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   @no_2gb('render fails')
   @no_4gb('render fails')
   def test_gl_stride(self):
-    self.btest('gl_stride.c', reference='gl_stride.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('gl_stride.c', 'gl_stride.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   @no_4gb('assertion failure')
   def test_gl_vertex_buffer_pre(self):
-    self.btest('gl_vertex_buffer_pre.c', reference='gl_vertex_buffer_pre.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('gl_vertex_buffer_pre.c', 'gl_vertex_buffer_pre.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   @no_4gb('assertion failure')
   def test_gl_vertex_buffer(self):
-    self.btest('gl_vertex_buffer.c', reference='gl_vertex_buffer.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], reference_slack=1)
+    self.reftest('gl_vertex_buffer.c', 'gl_vertex_buffer.png', args=['-sGL_UNSAFE_OPTS=0', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], reference_slack=1)
 
   @requires_graphics_hardware
   def test_gles2_uniform_arrays(self):
@@ -2082,12 +2079,12 @@ def test_matrix_identity(self):
   @requires_graphics_hardware
   @no_swiftshader
   def test_cubegeom_pre(self):
-    self.btest('third_party/cubegeom/cubegeom_pre.c', reference='third_party/cubegeom/cubegeom_pre.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_pre.c', 'third_party/cubegeom/cubegeom_pre.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   @no_swiftshader
   def test_cubegeom_pre_regal(self):
-    self.btest('third_party/cubegeom/cubegeom_pre.c', reference='third_party/cubegeom/cubegeom_pre.png', args=['-sUSE_REGAL', '-DUSE_REGAL', '-lGL', '-lSDL', '-lc++', '-lc++abi'])
+    self.reftest('third_party/cubegeom/cubegeom_pre.c', 'third_party/cubegeom/cubegeom_pre.png', args=['-sUSE_REGAL', '-DUSE_REGAL', '-lGL', '-lSDL', '-lc++', '-lc++abi'])
 
   @requires_graphics_hardware
   @no_swiftshader
@@ -2095,17 +2092,17 @@ def test_cubegeom_pre_relocatable(self):
     # RELOCATABLE needs to be set via `set_setting` so that it will also apply when
     # building `browser_reporting.c`
     self.set_setting('RELOCATABLE')
-    self.btest('third_party/cubegeom/cubegeom_pre.c', reference='third_party/cubegeom/cubegeom_pre.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_pre.c', 'third_party/cubegeom/cubegeom_pre.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   @no_swiftshader
   def test_cubegeom_pre2(self):
-    self.btest('third_party/cubegeom/cubegeom_pre2.c', reference='third_party/cubegeom/cubegeom_pre2.png', args=['-sGL_DEBUG', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL']) # some coverage for GL_DEBUG not breaking the build
+    self.reftest('third_party/cubegeom/cubegeom_pre2.c', 'third_party/cubegeom/cubegeom_pre2.png', args=['-sGL_DEBUG', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL']) # some coverage for GL_DEBUG not breaking the build
 
   @requires_graphics_hardware
   @no_swiftshader
   def test_cubegeom_pre3(self):
-    self.btest('third_party/cubegeom/cubegeom_pre3.c', reference='third_party/cubegeom/cubegeom_pre2.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_pre3.c', 'third_party/cubegeom/cubegeom_pre2.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @parameterized({
     '': ([],),
@@ -2115,16 +2112,16 @@ def test_cubegeom_pre3(self):
   def test_cubegeom(self, args):
     # proxy only in the simple, normal case (we can't trace GL calls when
     # proxied)
-    self.btest('third_party/cubegeom/cubegeom.c', reference='third_party/cubegeom/cubegeom.png', args=['-O2', '-g', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'] + args, also_proxied=not args)
+    self.reftest('third_party/cubegeom/cubegeom.c', 'third_party/cubegeom/cubegeom.png', args=['-O2', '-g', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'] + args, also_proxied=not args)
 
   @requires_graphics_hardware
   def test_cubegeom_regal(self):
-    self.btest('third_party/cubegeom/cubegeom.c', reference='third_party/cubegeom/cubegeom.png', args=['-O2', '-g', '-DUSE_REGAL', '-sUSE_REGAL', '-lGL', '-lSDL', '-lc++', '-lc++abi'], also_proxied=True)
+    self.reftest('third_party/cubegeom/cubegeom.c', 'third_party/cubegeom/cubegeom.png', args=['-O2', '-g', '-DUSE_REGAL', '-sUSE_REGAL', '-lGL', '-lSDL', '-lc++', '-lc++abi'], also_proxied=True)
 
   @requires_threads
   @requires_graphics_hardware
   def test_cubegeom_regal_mt(self):
-    self.btest('third_party/cubegeom/cubegeom.c', reference='third_party/cubegeom/cubegeom.png', args=['-O2', '-g', '-pthread', '-DUSE_REGAL', '-pthread', '-sUSE_REGAL', '-lGL', '-lSDL', '-lc++', '-lc++abi'], also_proxied=False)
+    self.reftest('third_party/cubegeom/cubegeom.c', 'third_party/cubegeom/cubegeom.png', args=['-O2', '-g', '-pthread', '-DUSE_REGAL', '-pthread', '-sUSE_REGAL', '-lGL', '-lSDL', '-lc++', '-lc++abi'], also_proxied=False)
 
   @requires_graphics_hardware
   @parameterized({
@@ -2146,118 +2143,118 @@ def test_cubegeom_proc(self, opts):
   return glBindBuffer;
 }
 ''')
-    self.btest('third_party/cubegeom/cubegeom_proc.c', reference='third_party/cubegeom/cubegeom.png', args=opts + ['side.c', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-sGL_ENABLE_GET_PROC_ADDRESS'])
+    self.reftest('third_party/cubegeom/cubegeom_proc.c', 'third_party/cubegeom/cubegeom.png', args=opts + ['side.c', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-sGL_ENABLE_GET_PROC_ADDRESS'])
 
   @also_with_wasmfs
   @requires_graphics_hardware
   def test_cubegeom_glew(self):
-    self.btest('third_party/cubegeom/cubegeom_glew.c', reference='third_party/cubegeom/cubegeom.png', args=['-O2', '--closure=1', '-sLEGACY_GL_EMULATION', '-lGL', '-lGLEW', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_glew.c', 'third_party/cubegeom/cubegeom.png', args=['-O2', '--closure=1', '-sLEGACY_GL_EMULATION', '-lGL', '-lGLEW', '-lSDL'])
 
   @requires_graphics_hardware
   def test_cubegeom_color(self):
-    self.btest('third_party/cubegeom/cubegeom_color.c', reference='third_party/cubegeom/cubegeom_color.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_color.c', 'third_party/cubegeom/cubegeom_color.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_cubegeom_normal(self):
-    self.btest('third_party/cubegeom/cubegeom_normal.c', reference='third_party/cubegeom/cubegeom_normal.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], also_proxied=True)
+    self.reftest('third_party/cubegeom/cubegeom_normal.c', 'third_party/cubegeom/cubegeom_normal.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], also_proxied=True)
 
   @requires_graphics_hardware
   def test_cubegeom_normal_dap(self): # draw is given a direct pointer to clientside memory, no element array buffer
-    self.btest('third_party/cubegeom/cubegeom_normal_dap.c', reference='third_party/cubegeom/cubegeom_normal.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], also_proxied=True)
+    self.reftest('third_party/cubegeom/cubegeom_normal_dap.c', 'third_party/cubegeom/cubegeom_normal.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], also_proxied=True)
 
   @requires_graphics_hardware
   def test_cubegeom_normal_dap_far(self): # indices do nto start from 0
-    self.btest('third_party/cubegeom/cubegeom_normal_dap_far.c', reference='third_party/cubegeom/cubegeom_normal.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_normal_dap_far.c', 'third_party/cubegeom/cubegeom_normal.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_cubegeom_normal_dap_far_range(self): # glDrawRangeElements
-    self.btest('third_party/cubegeom/cubegeom_normal_dap_far_range.c', reference='third_party/cubegeom/cubegeom_normal.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_normal_dap_far_range.c', 'third_party/cubegeom/cubegeom_normal.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_cubegeom_normal_dap_far_glda(self): # use glDrawArrays
-    self.btest('third_party/cubegeom/cubegeom_normal_dap_far_glda.c', reference='third_party/cubegeom/cubegeom_normal_dap_far_glda.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_normal_dap_far_glda.c', 'third_party/cubegeom/cubegeom_normal_dap_far_glda.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   @no_firefox('fails on CI but works locally')
   def test_cubegeom_normal_dap_far_glda_quad(self): # with quad
-    self.btest('third_party/cubegeom/cubegeom_normal_dap_far_glda_quad.c', reference='third_party/cubegeom/cubegeom_normal_dap_far_glda_quad.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_normal_dap_far_glda_quad.c', 'third_party/cubegeom/cubegeom_normal_dap_far_glda_quad.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_cubegeom_mt(self):
-    self.btest('third_party/cubegeom/cubegeom_mt.c', reference='third_party/cubegeom/cubegeom_mt.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL']) # multitexture
+    self.reftest('third_party/cubegeom/cubegeom_mt.c', 'third_party/cubegeom/cubegeom_mt.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL']) # multitexture
 
   @requires_graphics_hardware
   def test_cubegeom_color2(self):
-    self.btest('third_party/cubegeom/cubegeom_color2.c', reference='third_party/cubegeom/cubegeom_color2.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], also_proxied=True)
+    self.reftest('third_party/cubegeom/cubegeom_color2.c', 'third_party/cubegeom/cubegeom_color2.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], also_proxied=True)
 
   @requires_graphics_hardware
   def test_cubegeom_texturematrix(self):
-    self.btest('third_party/cubegeom/cubegeom_texturematrix.c', reference='third_party/cubegeom/cubegeom_texturematrix.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_texturematrix.c', 'third_party/cubegeom/cubegeom_texturematrix.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_cubegeom_fog(self):
-    self.btest('third_party/cubegeom/cubegeom_fog.c', reference='third_party/cubegeom/cubegeom_fog.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_fog.c', 'third_party/cubegeom/cubegeom_fog.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   @no_swiftshader
   def test_cubegeom_pre_vao(self):
-    self.btest('third_party/cubegeom/cubegeom_pre_vao.c', reference='third_party/cubegeom/cubegeom_pre_vao.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_pre_vao.c', 'third_party/cubegeom/cubegeom_pre_vao.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   @no_swiftshader
   def test_cubegeom_pre_vao_regal(self):
-    self.btest('third_party/cubegeom/cubegeom_pre_vao.c', reference='third_party/cubegeom/cubegeom_pre_vao.png', args=['-sUSE_REGAL', '-DUSE_REGAL', '-lGL', '-lSDL', '-lc++', '-lc++abi'])
+    self.reftest('third_party/cubegeom/cubegeom_pre_vao.c', 'third_party/cubegeom/cubegeom_pre_vao.png', args=['-sUSE_REGAL', '-DUSE_REGAL', '-lGL', '-lSDL', '-lc++', '-lc++abi'])
 
   @requires_graphics_hardware
   @no_swiftshader
   def test_cubegeom_pre2_vao(self):
-    self.btest('third_party/cubegeom/cubegeom_pre2_vao.c', reference='third_party/cubegeom/cubegeom_pre_vao.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-sGL_ENABLE_GET_PROC_ADDRESS'])
+    self.reftest('third_party/cubegeom/cubegeom_pre2_vao.c', 'third_party/cubegeom/cubegeom_pre_vao.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-sGL_ENABLE_GET_PROC_ADDRESS'])
 
   @requires_graphics_hardware
   def test_cubegeom_pre2_vao2(self):
-    self.btest('third_party/cubegeom/cubegeom_pre2_vao2.c', reference='third_party/cubegeom/cubegeom_pre2_vao2.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-sGL_ENABLE_GET_PROC_ADDRESS'])
+    self.reftest('third_party/cubegeom/cubegeom_pre2_vao2.c', 'third_party/cubegeom/cubegeom_pre2_vao2.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-sGL_ENABLE_GET_PROC_ADDRESS'])
 
   @requires_graphics_hardware
   @no_swiftshader
   def test_cubegeom_pre_vao_es(self):
-    self.btest('third_party/cubegeom/cubegeom_pre_vao_es.c', reference='third_party/cubegeom/cubegeom_pre_vao.png', args=['-sFULL_ES2', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_pre_vao_es.c', 'third_party/cubegeom/cubegeom_pre_vao.png', args=['-sFULL_ES2', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_cubegeom_u4fv_2(self):
-    self.btest('third_party/cubegeom/cubegeom_u4fv_2.c', reference='third_party/cubegeom/cubegeom_u4fv_2.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('third_party/cubegeom/cubegeom_u4fv_2.c', 'third_party/cubegeom/cubegeom_u4fv_2.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_cube_explosion(self):
-    self.btest('cube_explosion.c', reference='cube_explosion.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], also_proxied=True)
+    self.reftest('cube_explosion.c', 'cube_explosion.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], also_proxied=True)
 
   @requires_graphics_hardware
   def test_glgettexenv(self):
     self.btest('glgettexenv.c', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'], expected='1')
 
   def test_sdl_canvas_blank(self):
-    self.btest('test_sdl_canvas_blank.c', args=['-lSDL', '-lGL'], reference='browser/test_sdl_canvas_blank.png')
+    self.reftest('test_sdl_canvas_blank.c', 'test_sdl_canvas_blank.png', args=['-lSDL', '-lGL'])
 
   def test_sdl_canvas_palette(self):
-    self.btest('test_sdl_canvas_palette.c', args=['-lSDL', '-lGL'], reference='browser/test_sdl_canvas_palette.png')
+    self.reftest('test_sdl_canvas_palette.c', 'test_sdl_canvas_palette.png', args=['-lSDL', '-lGL'])
 
   def test_sdl_canvas_twice(self):
-    self.btest('test_sdl_canvas_twice.c', args=['-lSDL', '-lGL'], reference='browser/test_sdl_canvas_twice.png')
+    self.reftest('test_sdl_canvas_twice.c', 'test_sdl_canvas_twice.png', args=['-lSDL', '-lGL'])
 
   def test_sdl_set_clip_rect(self):
-    self.btest('test_sdl_set_clip_rect.c', args=['-lSDL', '-lGL'], reference='browser/test_sdl_set_clip_rect.png')
+    self.reftest('test_sdl_set_clip_rect.c', 'test_sdl_set_clip_rect.png', args=['-lSDL', '-lGL'])
 
   def test_sdl_maprgba(self):
-    self.btest('test_sdl_maprgba.c', args=['-lSDL', '-lGL'], reference='browser/test_sdl_maprgba.png', reference_slack=3)
+    self.reftest('test_sdl_maprgba.c', 'test_sdl_maprgba.png', args=['-lSDL', '-lGL'], reference_slack=3)
 
   def test_sdl_create_rgb_surface_from(self):
-    self.btest('test_sdl_create_rgb_surface_from.c', args=['-lSDL', '-lGL'], reference='browser/test_sdl_create_rgb_surface_from.png')
+    self.reftest('test_sdl_create_rgb_surface_from.c', 'test_sdl_create_rgb_surface_from.png', args=['-lSDL', '-lGL'])
 
   def test_sdl_rotozoom(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl_rotozoom.c', reference='browser/test_sdl_rotozoom.png', args=['--preload-file', 'screenshot.png', '--use-preload-plugins', '-lSDL', '-lGL'], reference_slack=3)
+    self.reftest('test_sdl_rotozoom.c', 'test_sdl_rotozoom.png', args=['--preload-file', 'screenshot.png', '--use-preload-plugins', '-lSDL', '-lGL'], reference_slack=3)
 
   def test_sdl_gfx_primitives(self):
-    self.btest('test_sdl_gfx_primitives.c', args=['-lSDL', '-lGL'], reference='browser/test_sdl_gfx_primitives.png', reference_slack=1)
+    self.reftest('test_sdl_gfx_primitives.c', 'test_sdl_gfx_primitives.png', args=['-lSDL', '-lGL'], reference_slack=1)
 
   def test_sdl_canvas_palette_2(self):
     create_file('pre.js', '''
@@ -2278,12 +2275,12 @@ def test_sdl_canvas_palette_2(self):
       Module['arguments'] = ['-b'];
     ''')
 
-    self.btest('test_sdl_canvas_palette_2.c', reference='browser/test_sdl_canvas_palette_r.png', args=['--pre-js', 'pre.js', '--pre-js', 'args-r.js', '-lSDL', '-lGL'])
-    self.btest('test_sdl_canvas_palette_2.c', reference='browser/test_sdl_canvas_palette_g.png', args=['--pre-js', 'pre.js', '--pre-js', 'args-g.js', '-lSDL', '-lGL'])
-    self.btest('test_sdl_canvas_palette_2.c', reference='browser/test_sdl_canvas_palette_b.png', args=['--pre-js', 'pre.js', '--pre-js', 'args-b.js', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_canvas_palette_2.c', 'test_sdl_canvas_palette_r.png', args=['--pre-js', 'pre.js', '--pre-js', 'args-r.js', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_canvas_palette_2.c', 'test_sdl_canvas_palette_g.png', args=['--pre-js', 'pre.js', '--pre-js', 'args-g.js', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_canvas_palette_2.c', 'test_sdl_canvas_palette_b.png', args=['--pre-js', 'pre.js', '--pre-js', 'args-b.js', '-lSDL', '-lGL'])
 
   def test_sdl_ttf_render_text_solid(self):
-    self.btest('test_sdl_ttf_render_text_solid.c', reference='browser/test_sdl_ttf_render_text_solid.png', args=['-O2', '-lSDL', '-lGL'])
+    self.reftest('test_sdl_ttf_render_text_solid.c', 'test_sdl_ttf_render_text_solid.png', args=['-O2', '-lSDL', '-lGL'])
 
   def test_sdl_alloctext(self):
     self.btest_exit('test_sdl_alloctext.c', args=['-lSDL', '-lGL'])
@@ -2292,35 +2289,35 @@ def test_sdl_surface_refcount(self):
     self.btest_exit('test_sdl_surface_refcount.c', args=['-lSDL'])
 
   def test_sdl_free_screen(self):
-    self.btest('test_sdl_free_screen.cpp', args=['-lSDL', '-lGL'], reference='htmltest.png')
+    self.reftest('test_sdl_free_screen.cpp', 'htmltest.png', args=['-lSDL', '-lGL'])
 
   @requires_graphics_hardware
   def test_glbegin_points(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('glbegin_points.c', reference='glbegin_points.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'])
+    self.reftest('glbegin_points.c', 'glbegin_points.png', args=['--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '--use-preload-plugins'])
 
   @requires_graphics_hardware
   def test_s3tc(self):
     shutil.copyfile(test_file('screenshot.dds'), 'screenshot.dds')
-    self.btest('s3tc.c', reference='s3tc.png', args=['--preload-file', 'screenshot.dds', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('s3tc.c', 's3tc.png', args=['--preload-file', 'screenshot.dds', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_s3tc_ffp_only(self):
     shutil.copyfile(test_file('screenshot.dds'), 'screenshot.dds')
-    self.btest('s3tc.c', reference='s3tc.png', args=['--preload-file', 'screenshot.dds', '-sLEGACY_GL_EMULATION', '-sGL_FFP_ONLY', '-lGL', '-lSDL'])
+    self.reftest('s3tc.c', 's3tc.png', args=['--preload-file', 'screenshot.dds', '-sLEGACY_GL_EMULATION', '-sGL_FFP_ONLY', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_anisotropic(self):
     shutil.copyfile(test_file('browser/water.dds'), 'water.dds')
-    self.btest('test_anisotropic.c', reference='browser/test_anisotropic.png', reference_slack=2, args=['--preload-file', 'water.dds', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-Wno-incompatible-pointer-types'])
+    self.reftest('test_anisotropic.c', 'test_anisotropic.png', reference_slack=2, args=['--preload-file', 'water.dds', '-sLEGACY_GL_EMULATION', '-lGL', '-lSDL', '-Wno-incompatible-pointer-types'])
 
   @requires_graphics_hardware
   def test_tex_nonbyte(self):
-    self.btest('tex_nonbyte.c', reference='tex_nonbyte.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('tex_nonbyte.c', 'tex_nonbyte.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_float_tex(self):
-    self.btest('float_tex.c', reference='float_tex.png', args=['-lGL', '-lglut'])
+    self.reftest('float_tex.c', 'float_tex.png', args=['-lGL', '-lglut'])
 
   @requires_graphics_hardware
   @parameterized({
@@ -2332,11 +2329,11 @@ def test_float_tex(self):
   def test_subdata(self, args):
     if self.is_4gb() and '-sMIN_WEBGL_VERSION=2' in args:
       self.skipTest('texSubImage2D fails: https://crbug.com/325090165')
-    self.btest('gl_subdata.c', reference='float_tex.png', args=['-lGL', '-lglut'] + args)
+    self.reftest('gl_subdata.c', 'float_tex.png', args=['-lGL', '-lglut'] + args)
 
   @requires_graphics_hardware
   def test_perspective(self):
-    self.btest('perspective.c', reference='perspective.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
+    self.reftest('perspective.c', 'perspective.png', args=['-sLEGACY_GL_EMULATION', '-lGL', '-lSDL'])
 
   @requires_graphics_hardware
   def test_glerror(self):
@@ -2863,21 +2860,21 @@ def test_webgl2_pbo(self):
   @requires_graphics_hardware
   @no_4gb('fails to render')
   def test_webgl2_sokol_mipmap(self):
-    self.btest('third_party/sokol/mipmap-emsc.c', args=['-sMAX_WEBGL_VERSION=2', '-lGL', '-O1'],
-               reference='third_party/sokol/mipmap-emsc.png', reference_slack=2)
+    self.reftest('third_party/sokol/mipmap-emsc.c', 'third_party/sokol/mipmap-emsc.png',
+                 args=['-sMAX_WEBGL_VERSION=2', '-lGL', '-O1'], reference_slack=2)
 
   @no_firefox('fails on CI likely due to GPU drivers there')
   @no_4gb('fails to render')
   @requires_graphics_hardware
   def test_webgl2_sokol_mrt(self):
-    self.btest('third_party/sokol/mrt-emcc.c', args=['-sMAX_WEBGL_VERSION=2', '-lGL'],
-               reference='third_party/sokol/mrt-emcc.png')
+    self.reftest('third_party/sokol/mrt-emcc.c', 'third_party/sokol/mrt-emcc.png',
+                 args=['-sMAX_WEBGL_VERSION=2', '-lGL'])
 
   @requires_graphics_hardware
   @no_4gb('fails to render')
   def test_webgl2_sokol_arraytex(self):
-    self.btest('third_party/sokol/arraytex-emsc.c', args=['-sMAX_WEBGL_VERSION=2', '-lGL'],
-               reference='third_party/sokol/arraytex-emsc.png')
+    self.reftest('third_party/sokol/arraytex-emsc.c', 'third_party/sokol/arraytex-emsc.png',
+                 args=['-sMAX_WEBGL_VERSION=2', '-lGL'])
 
   @parameterized({
     '': ([],),
@@ -3218,28 +3215,28 @@ def test_sdl2_threads(self):
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_glshader(self):
-    self.btest('test_sdl2_glshader.c', reference='browser/test_sdl_glshader.png', args=['-sUSE_SDL=2', '-O2', '--closure=1', '-g1', '-sLEGACY_GL_EMULATION'])
-    self.btest('test_sdl2_glshader.c', reference='browser/test_sdl_glshader.png', args=['-sUSE_SDL=2', '-O2', '-sLEGACY_GL_EMULATION'], also_proxied=True) # XXX closure fails on proxy
+    self.reftest('test_sdl2_glshader.c', 'test_sdl_glshader.png', args=['-sUSE_SDL=2', '-O2', '--closure=1', '-g1', '-sLEGACY_GL_EMULATION'])
+    self.reftest('test_sdl2_glshader.c', 'test_sdl_glshader.png', args=['-sUSE_SDL=2', '-O2', '-sLEGACY_GL_EMULATION'], also_proxied=True) # XXX closure fails on proxy
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_canvas_blank(self):
-    self.btest('test_sdl2_canvas_blank.c', reference='browser/test_sdl_canvas_blank.png', args=['-sUSE_SDL=2'])
+    self.reftest('test_sdl2_canvas_blank.c', 'test_sdl_canvas_blank.png', args=['-sUSE_SDL=2'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_canvas_palette(self):
-    self.btest('test_sdl2_canvas_palette.c', reference='browser/test_sdl_canvas_palette.png', args=['-sUSE_SDL=2'])
+    self.reftest('test_sdl2_canvas_palette.c', 'test_sdl_canvas_palette.png', args=['-sUSE_SDL=2'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_canvas_twice(self):
-    self.btest('test_sdl2_canvas_twice.c', reference='browser/test_sdl_canvas_twice.png', args=['-sUSE_SDL=2'])
+    self.reftest('test_sdl2_canvas_twice.c', 'test_sdl_canvas_twice.png', args=['-sUSE_SDL=2'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_gfx(self):
-    self.btest('test_sdl2_gfx.cpp', args=['-sUSE_SDL=2', '-sUSE_SDL_GFX=2'], reference='browser/test_sdl2_gfx.png', reference_slack=2)
+    self.reftest('test_sdl2_gfx.cpp', 'test_sdl2_gfx.png', args=['-sUSE_SDL=2', '-sUSE_SDL_GFX=2'], reference_slack=2)
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
@@ -3256,9 +3253,9 @@ def test_sdl2_canvas_palette_2(self):
       Module['arguments'] = ['-b'];
     ''')
 
-    self.btest('test_sdl2_canvas_palette_2.c', reference='browser/test_sdl_canvas_palette_r.png', args=['-sUSE_SDL=2', '--pre-js', 'args-r.js'])
-    self.btest('test_sdl2_canvas_palette_2.c', reference='browser/test_sdl_canvas_palette_g.png', args=['-sUSE_SDL=2', '--pre-js', 'args-g.js'])
-    self.btest('test_sdl2_canvas_palette_2.c', reference='browser/test_sdl_canvas_palette_b.png', args=['-sUSE_SDL=2', '--pre-js', 'args-b.js'])
+    self.reftest('test_sdl2_canvas_palette_2.c', 'test_sdl_canvas_palette_r.png', args=['-sUSE_SDL=2', '--pre-js', 'args-r.js'])
+    self.reftest('test_sdl2_canvas_palette_2.c', 'test_sdl_canvas_palette_g.png', args=['-sUSE_SDL=2', '--pre-js', 'args-g.js'])
+    self.reftest('test_sdl2_canvas_palette_2.c', 'test_sdl_canvas_palette_b.png', args=['-sUSE_SDL=2', '--pre-js', 'args-b.js'])
 
   @no_wasm64('SDL2 + wasm64')
   def test_sdl2_swsurface(self):
@@ -3269,21 +3266,21 @@ def test_sdl2_swsurface(self):
   def test_sdl2_image_prepare(self):
     # load an image file, get pixel data.
     shutil.copyfile(test_file('screenshot.jpg'), 'screenshot.not')
-    self.btest('test_sdl2_image_prepare.c', reference='screenshot.jpg', args=['--preload-file', 'screenshot.not', '-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2'], manually_trigger_reftest=True)
+    self.reftest('test_sdl2_image_prepare.c', 'screenshot.jpg', args=['--preload-file', 'screenshot.not', '-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2'], manually_trigger_reftest=True)
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_image_prepare_data(self):
     # load an image file, get pixel data.
     shutil.copyfile(test_file('screenshot.jpg'), 'screenshot.not')
-    self.btest('test_sdl2_image_prepare_data.c', reference='screenshot.jpg', args=['--preload-file', 'screenshot.not', '-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2'], manually_trigger_reftest=True)
+    self.reftest('test_sdl2_image_prepare_data.c', 'screenshot.jpg', args=['--preload-file', 'screenshot.not', '-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2'], manually_trigger_reftest=True)
 
   @no_wasm64('SDL2 + wasm64')
   @no_2gb('https://github.com/libsdl-org/SDL/issues/9052')
   @requires_graphics_hardware
   def test_sdl2_canvas_proxy(self):
     create_file('data.txt', 'datum')
-    self.btest('test_sdl2_canvas_proxy.c', reference='browser/test_sdl2_canvas.png', args=['-sUSE_SDL=2', '--proxy-to-worker', '--preload-file', 'data.txt', '-sGL_TESTING'], manual_reference=True, post_build=self.post_manual_reftest)
+    self.reftest('test_sdl2_canvas_proxy.c', 'test_sdl2_canvas.png', args=['-sUSE_SDL=2', '--proxy-to-worker', '--preload-file', 'data.txt', '-sGL_TESTING'], manual_reference=True, post_build=self.post_manual_reftest)
 
   @no_wasm64('SDL2 + wasm64')
   def test_sdl2_pumpevents(self):
@@ -3314,61 +3311,61 @@ def test_sdl2_gl_read(self):
   @no_2gb('https://github.com/libsdl-org/SDL/issues/9052')
   @requires_graphics_hardware
   def test_sdl2_glmatrixmode_texture(self):
-    self.btest('test_sdl2_glmatrixmode_texture.c', reference='browser/test_sdl2_glmatrixmode_texture.png',
-               args=['-sLEGACY_GL_EMULATION', '-sUSE_SDL=2'])
+    self.reftest('test_sdl2_glmatrixmode_texture.c', 'test_sdl2_glmatrixmode_texture.png',
+                 args=['-sLEGACY_GL_EMULATION', '-sUSE_SDL=2'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_gldrawelements(self):
-    self.btest('test_sdl2_gldrawelements.c', reference='browser/test_sdl2_gldrawelements.png',
-               args=['-sLEGACY_GL_EMULATION', '-sUSE_SDL=2'])
+    self.reftest('test_sdl2_gldrawelements.c', 'test_sdl2_gldrawelements.png',
+                 args=['-sLEGACY_GL_EMULATION', '-sUSE_SDL=2'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_glclipplane_gllighting(self):
-    self.btest('test_sdl2_glclipplane_gllighting.c', reference='browser/test_sdl2_glclipplane_gllighting.png',
-               args=['-sLEGACY_GL_EMULATION', '-sUSE_SDL=2'])
+    self.reftest('test_sdl2_glclipplane_gllighting.c', 'test_sdl2_glclipplane_gllighting.png',
+                 args=['-sLEGACY_GL_EMULATION', '-sUSE_SDL=2'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_glalphatest(self):
-    self.btest('test_sdl2_glalphatest.c', reference='browser/test_sdl2_glalphatest.png',
-               args=['-sLEGACY_GL_EMULATION', '-sUSE_SDL=2'])
+    self.reftest('test_sdl2_glalphatest.c', 'test_sdl2_glalphatest.png',
+                 args=['-sLEGACY_GL_EMULATION', '-sUSE_SDL=2'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_fog_simple(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl2_fog_simple.c', reference='screenshot-fog-simple.png',
-               args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '-O2', '--minify=0', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
+    self.reftest('test_sdl2_fog_simple.c', 'screenshot-fog-simple.png',
+                 args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '-O2', '--minify=0', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_fog_negative(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl2_fog_negative.c', reference='screenshot-fog-negative.png',
-               args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
+    self.reftest('test_sdl2_fog_negative.c', 'screenshot-fog-negative.png',
+                 args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_fog_density(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl2_fog_density.c', reference='screenshot-fog-density.png',
-               args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
+    self.reftest('test_sdl2_fog_density.c', 'screenshot-fog-density.png',
+                 args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_fog_exp2(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl2_fog_exp2.c', reference='screenshot-fog-exp2.png',
-               args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
+    self.reftest('test_sdl2_fog_exp2.c', 'screenshot-fog-exp2.png',
+                 args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_fog_linear(self):
     shutil.copyfile(test_file('screenshot.png'), 'screenshot.png')
-    self.btest('test_sdl2_fog_linear.c', reference='screenshot-fog-linear.png', reference_slack=1,
-               args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
+    self.reftest('test_sdl2_fog_linear.c', 'screenshot-fog-linear.png', reference_slack=1,
+                 args=['-sUSE_SDL=2', '-sUSE_SDL_IMAGE=2', '--preload-file', 'screenshot.png', '-sLEGACY_GL_EMULATION', '--use-preload-plugins'])
 
   @no_wasm64('SDL2 + wasm64')
   def test_sdl2_unwasteful(self):
@@ -3389,21 +3386,21 @@ def post_build():
       reftest2 = reftest.replace("Module['postRun'] = doReftest;", '') # we don't want the very first frame
       assert reftest != reftest2
       create_file('reftest.js', reftest2)
-    self.btest('test_sdl2_gl_frames_swap.c', reference='browser/test_sdl2_gl_frames_swap.png', args=['--proxy-to-worker', '-sGL_TESTING', '-sUSE_SDL=2'], manual_reference=True, post_build=post_build)
+    self.reftest('test_sdl2_gl_frames_swap.c', 'test_sdl2_gl_frames_swap.png', args=['--proxy-to-worker', '-sGL_TESTING', '-sUSE_SDL=2'], manual_reference=True, post_build=post_build)
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_ttf(self):
     shutil.copy2(test_file('freetype/LiberationSansBold.ttf'), self.get_dir())
-    self.btest('test_sdl2_ttf.c', reference='browser/test_sdl2_ttf.png',
-               args=['-O2', '-sUSE_SDL=2', '-sUSE_SDL_TTF=2', '--embed-file', 'LiberationSansBold.ttf'])
+    self.reftest('test_sdl2_ttf.c', 'test_sdl2_ttf.png',
+                 args=['-O2', '-sUSE_SDL=2', '-sUSE_SDL_TTF=2', '--embed-file', 'LiberationSansBold.ttf'])
 
   @no_wasm64('SDL2 + wasm64')
   @requires_graphics_hardware
   def test_sdl2_ttf_rtl(self):
     shutil.copy2(test_file('third_party/notofont/NotoNaskhArabic-Regular.ttf'), self.get_dir())
-    self.btest('test_sdl2_ttf_rtl.c', reference='browser/test_sdl2_ttf_rtl.png',
-               args=['-O2', '-sUSE_SDL=2', '-sUSE_SDL_TTF=2', '--embed-file', 'NotoNaskhArabic-Regular.ttf'])
+    self.reftest('test_sdl2_ttf_rtl.c', 'test_sdl2_ttf_rtl.png',
+                 args=['-O2', '-sUSE_SDL=2', '-sUSE_SDL_TTF=2', '--embed-file', 'NotoNaskhArabic-Regular.ttf'])
 
   @no_wasm64('SDL2 + wasm64')
   def test_sdl2_custom_cursor(self):
@@ -3467,17 +3464,17 @@ def test_cocos2d_hello(self):
     # e.g. warning: undefined symbol: TIFFClientOpen
     cocos2d_root = os.path.join(ports.Ports.get_dir(), 'cocos2d', 'Cocos2d-version_3_3')
     preload_file = os.path.join(cocos2d_root, 'samples', 'Cpp', 'HelloCpp', 'Resources') + '@'
-    self.btest('cocos2d_hello.cpp', reference='cocos2d_hello.png', reference_slack=1,
-               args=['-sUSE_COCOS2D=3', '-sERROR_ON_UNDEFINED_SYMBOLS=0',
-                     # This line should really just be `-std=c++14` like we use to compile
-                     # the cocos library itself, but that doesn't work in this case because
-                     # btest adds browser_reporting.c to the command.
-                     '-D_LIBCPP_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION',
-                     '-Wno-js-compiler',
-                     '-Wno-experimental',
-                     '--preload-file', preload_file, '--use-preload-plugins',
-                     '-Wno-inconsistent-missing-override',
-                     '-Wno-deprecated-declarations'])
+    self.reftest('cocos2d_hello.cpp', 'cocos2d_hello.png', reference_slack=1,
+                 args=['-sUSE_COCOS2D=3', '-sERROR_ON_UNDEFINED_SYMBOLS=0',
+                       # This line should really just be `-std=c++14` like we use to compile
+                       # the cocos library itself, but that doesn't work in this case because
+                       # btest adds browser_reporting.c to the command.
+                       '-D_LIBCPP_ENABLE_CXX17_REMOVED_UNARY_BINARY_FUNCTION',
+                       '-Wno-js-compiler',
+                       '-Wno-experimental',
+                       '--preload-file', preload_file, '--use-preload-plugins',
+                       '-Wno-inconsistent-missing-override',
+                       '-Wno-deprecated-declarations'])
 
   @parameterized({
     'asyncify': (['-sASYNCIFY=1'],),
@@ -4688,9 +4685,8 @@ def test_webgl_from_client_side_memory_without_default_enabled_extensions(self):
     'elements_instanced': (['-DMULTI_DRAW_ELEMENTS_INSTANCED'],),
   })
   def test_webgl_multi_draw(self, args):
-    self.btest('webgl_multi_draw_test.c',
-               reference='browser/webgl_multi_draw.png',
-               args=['-lGL', '-sOFFSCREEN_FRAMEBUFFER', '-DEXPLICIT_SWAP'] + args)
+    self.reftest('webgl_multi_draw_test.c', 'webgl_multi_draw.png',
+                 args=['-lGL', '-sOFFSCREEN_FRAMEBUFFER', '-DEXPLICIT_SWAP'] + args)
 
   # Tests for base_vertex/base_instance extension
   # For testing WebGL draft extensions like this, if using chrome as the browser,
@@ -4701,14 +4697,14 @@ def test_webgl_multi_draw(self, args):
   def test_webgl_draw_base_vertex_base_instance(self):
     for multiDraw in [0, 1]:
       for drawElements in [0, 1]:
-        self.btest('webgl_draw_base_vertex_base_instance_test.c', reference='browser/webgl_draw_instanced_base_vertex_base_instance.png',
-                   args=['-lGL',
-                         '-sMAX_WEBGL_VERSION=2',
-                         '-sOFFSCREEN_FRAMEBUFFER',
-                         '-DMULTI_DRAW=' + str(multiDraw),
-                         '-DDRAW_ELEMENTS=' + str(drawElements),
-                         '-DEXPLICIT_SWAP=1',
-                         '-DWEBGL_CONTEXT_VERSION=2'])
+        self.reftest('webgl_draw_base_vertex_base_instance_test.c', 'webgl_draw_instanced_base_vertex_base_instance.png',
+                     args=['-lGL',
+                           '-sMAX_WEBGL_VERSION=2',
+                           '-sOFFSCREEN_FRAMEBUFFER',
+                           '-DMULTI_DRAW=' + str(multiDraw),
+                           '-DDRAW_ELEMENTS=' + str(drawElements),
+                           '-DEXPLICIT_SWAP=1',
+                           '-DWEBGL_CONTEXT_VERSION=2'])
 
   @requires_graphics_hardware
   @no_4gb('fails to render')
@@ -4771,7 +4767,7 @@ def test_webgl_offscreen_framebuffer_state_restoration(self):
   @requires_graphics_hardware
   @no_4gb('fails to render')
   def test_webgl_array_of_structs_uniform(self):
-    self.btest('webgl_array_of_structs_uniform.c', args=['-lGL', '-sMAX_WEBGL_VERSION=2'], reference='browser/webgl_array_of_structs_uniform.png')
+    self.reftest('webgl_array_of_structs_uniform.c', 'webgl_array_of_structs_uniform.png', args=['-lGL', '-sMAX_WEBGL_VERSION=2'])
 
   # Tests that if a WebGL context is created in a pthread on a canvas that has
   # not been transferred to that pthread, WebGL calls are then proxied to the
@@ -5717,7 +5713,7 @@ def test_wasmfs_opfs_errors(self):
     test = test_file('wasmfs/wasmfs_opfs_errors.c')
     postjs = test_file('wasmfs/wasmfs_opfs_errors_post.js')
     args = ['-sWASMFS', '-pthread', '-sPROXY_TO_PTHREAD', '--post-js', postjs]
-    self.btest(test, args=args, expected="0")
+    self.btest(test, args=args, expected='0')
 
   @no_firefox('no 4GB support yet')
   def test_emmalloc_memgrowth(self, *args):