Use the Scaler object

src/libretro/platform/platform.cpp

@@ -16,6 +16,8 @@
 
 #include <array>
 #include <cstdarg>
+#include <cstdio>
+#include <memory>
 
 #include <gfx/scaler/scaler.h>
 #include <libretro.h>
@@ -28,12 +30,13 @@
 #include "../memory.hpp"
 #include "../environment.hpp"
 #include "../config.hpp"
+#include "retro/scaler.hpp"
 #include "sram.hpp"
 
 constexpr unsigned DSI_CAMERA_WIDTH = 640;
 constexpr unsigned DSI_CAMERA_HEIGHT = 480;
 static struct retro_camera_callback _camera{};
-static struct scaler_ctx _scaler{};
+static std::unique_ptr<retro::Scaler> scaler{};
 
 // YUV422 framebuffer, two pixels per 32-bit int (see DSi_Camera.h)
 static std::array<uint32_t, DSI_CAMERA_WIDTH * DSI_CAMERA_HEIGHT / 2> _camera_buffer{};
@@ -100,25 +103,13 @@ static void conv_argb8888_yuyv(void *output_, const void *input_,
 
 static void CaptureImage(const uint32_t *buffer, unsigned width, unsigned height, size_t pitch) noexcept {
 
-    if (_scaler.in_width != static_cast<int>(width) || _scaler.in_height != static_cast<int>(height) ||
-        _scaler.in_stride != static_cast<int>(pitch)) {
-        // If the camera's dimensions changed behind our back (or haven't been initialized)...
-        _scaler.in_width = width;
-        _scaler.in_height = height;
-        _scaler.in_stride = pitch;
-        _scaler.out_width = DSI_CAMERA_WIDTH;
-        _scaler.out_height = DSI_CAMERA_HEIGHT;
-        _scaler.out_stride = DSI_CAMERA_WIDTH * sizeof(uint32_t) / 2;
-        _scaler.direct_pixconv = conv_argb8888_yuyv;
-        _scaler.in_pixconv = nullptr;
-        _scaler.out_pixconv = conv_argb8888_yuyv;
-
-        if (!scaler_ctx_gen_filter(&_scaler)) {
-            retro::warn("Failed to initialize camera scaler.");
-        }
+    if (!scaler || scaler->InWidth() != width || scaler->InHeight() != height || scaler->InStride() != pitch) {
+        // If the scaler hasn't been initialized, or if the camera's dimensions changed behind our back...
+
+        scaler = std::make_unique<retro::Scaler>(SCALER_FMT_ARGB8888, SCALER_FMT_RGBA4444, SCALER_TYPE_BILINEAR, width, height, DSI_CAMERA_WIDTH, DSI_CAMERA_HEIGHT);
     }
 
-    scaler_ctx_scale(&_scaler, _camera_buffer.data(), buffer);
+    scaler->Scale(_camera_buffer.data(), buffer);
 }
 
 void Platform::Init(int, char **) {
@@ -136,10 +127,6 @@ void Platform::Init(int, char **) {
     _camera.width = DSI_CAMERA_WIDTH;
     _camera.height = DSI_CAMERA_HEIGHT;
 
-    _scaler.in_fmt = SCALER_FMT_ARGB8888;
-    _scaler.out_fmt = SCALER_FMT_YUYV;
-    _scaler.scaler_type = SCALER_TYPE_BILINEAR; // TODO: Make configurable
-
     if (!retro::environment(RETRO_ENVIRONMENT_GET_CAMERA_INTERFACE, &_camera)) {
         retro::warn("Camera interface not available.");
     } else {
@@ -157,7 +144,7 @@ void Platform::DeInit() {
 
     _camera.start = nullptr;
     _camera.stop = nullptr;
-    scaler_ctx_gen_reset(&_scaler);
+    scaler.reset();
 }
 
 void Platform::SignalStop(Platform::StopReason reason) {

src/libretro/retro/scaler.cpp

@@ -17,6 +17,7 @@
 #include "scaler.hpp"
 
 #include <stdexcept>
+#include <retro_assert.h>
 
 constexpr unsigned PixelSize(scaler_pix_fmt fmt) noexcept {
     switch (fmt) {
@@ -56,6 +57,10 @@ const char* PixelFormatName(scaler_pix_fmt fmt) noexcept {
     }
 }
 
+retro::Scaler::Scaler() noexcept {
+
+}
+
 retro::Scaler::Scaler(
     scaler_pix_fmt in_fmt,
     scaler_pix_fmt out_fmt,
@@ -94,6 +99,17 @@ retro::Scaler::Scaler(
     }
 }
 
+retro::Scaler::Scaler(scaler_ctx&& ctx) noexcept {
+    scaler = ctx;
+    ctx = {};
+
+    retro_assert(ctx.input.frame == nullptr);
+    retro_assert(ctx.scaled.frame == nullptr);
+    retro_assert(ctx.output.frame == nullptr);
+    retro_assert(ctx.in_pixconv == nullptr);
+    retro_assert(ctx.out_pixconv == nullptr);
+}
+
 retro::Scaler::~Scaler() noexcept {
     scaler_ctx_gen_reset(&scaler);
 }

src/libretro/retro/scaler.hpp

@@ -22,7 +22,9 @@
 namespace retro {
     class Scaler {
     public:
+        Scaler() noexcept;
         Scaler(scaler_pix_fmt in_fmt, scaler_pix_fmt out_fmt, scaler_type type, unsigned in_width, unsigned in_height, unsigned out_width, unsigned out_height);
+        Scaler(scaler_ctx&& ctx) noexcept;
         ~Scaler() noexcept;
         Scaler(const Scaler&) = delete;
         Scaler(Scaler&&) noexcept;

src/libretro/screenlayout.cpp

@@ -54,7 +54,6 @@ melonds::ScreenLayoutData::ScreenLayoutData() :
 }
 
 melonds::ScreenLayoutData::~ScreenLayoutData() noexcept {
-    scaler_ctx_gen_reset(&hybridScaler);
 }
 
 void melonds::ScreenLayoutData::CopyScreen(const uint32_t* src, glm::uvec2 destTranslation) noexcept {
@@ -120,7 +119,7 @@ void melonds::ScreenLayoutData::CombineScreens(const uint32_t* topBuffer, const
         retro_assert(hybridBuffer);
         const uint32_t* primaryBuffer = layout == ScreenLayout::HybridTop ? topBuffer : bottomBuffer;
 
-        scaler_ctx_scale(&hybridScaler, hybridBuffer.Buffer(), primaryBuffer);
+        hybridScaler.Scale(hybridBuffer.Buffer(), primaryBuffer);
         buffer.CopyRows(hybridBuffer.Buffer(), hybridScreenTranslation, NDS_SCREEN_SIZE<unsigned> * hybridRatio);
 
         HybridSideScreenDisplay smallScreenLayout = HybridSmallScreenLayout();
@@ -323,16 +322,15 @@ void melonds::ScreenLayoutData::Update(melonds::Renderer renderer) noexcept {
             // TODO: Don't recreate this buffer if the hybrid ratio didn't change
             // TODO: Maintain a separate _hybridDirty flag
             hybridBuffer = PixelBuffer(NDS_SCREEN_SIZE<unsigned> * hybridRatio);
-            hybridScaler.in_width = NDS_SCREEN_WIDTH;
-            hybridScaler.in_height = NDS_SCREEN_HEIGHT;
-            hybridScaler.in_stride = NDS_SCREEN_WIDTH * sizeof(uint32_t);
-            hybridScaler.out_width = NDS_SCREEN_WIDTH * hybridRatio;
-            hybridScaler.out_height = NDS_SCREEN_HEIGHT * hybridRatio;
-            hybridScaler.out_stride = NDS_SCREEN_WIDTH * hybridRatio * sizeof(uint32_t);
-            hybridScaler.in_fmt = SCALER_FMT_ARGB8888;
-            hybridScaler.out_fmt = SCALER_FMT_ARGB8888;
-            hybridScaler.scaler_type = config::video::ScreenFilter() == ScreenFilter::Nearest ? SCALER_TYPE_POINT : SCALER_TYPE_BILINEAR;
-            scaler_ctx_gen_filter(&hybridScaler);
+            hybridScaler = retro::Scaler(
+                SCALER_FMT_ARGB8888,
+                SCALER_FMT_ARGB8888,
+                config::video::ScreenFilter() == ScreenFilter::Nearest ? SCALER_TYPE_POINT : SCALER_TYPE_BILINEAR,
+                NDS_SCREEN_WIDTH,
+                NDS_SCREEN_HEIGHT,
+                NDS_SCREEN_WIDTH * hybridRatio,
+                NDS_SCREEN_HEIGHT * hybridRatio
+            );
         } else {
             hybridBuffer = nullptr;
         }

src/libretro/screenlayout.hpp

@@ -33,6 +33,7 @@
 #include "environment.hpp"
 #include "input.hpp"
 #include "buffer.hpp"
+#include "retro/scaler.hpp"
 
 namespace melonds {
     /// The native width of a single Nintendo DS screen, in pixels
@@ -228,7 +229,7 @@ namespace melonds {
 
         // Used as a staging area for the hybrid screen to be scaled
         PixelBuffer hybridBuffer;
-        struct scaler_ctx hybridScaler;
+        retro::Scaler hybridScaler;
     };
 
     constexpr bool LayoutSupportsScreenGap(ScreenLayout layout) noexcept {