Update the old ray shader

data/shader/surface.inc.glsl

@@ -41,20 +41,16 @@ int modulo(int a, int b) {
 float get_lod_height(ivec2 ipos, int lod) {
     int x = modulo(ipos.x, int(u_TextureScale.x));
     int y = modulo(ipos.y, int(u_TextureScale.y));
-    ivec3 tc = ivec3(
-        x >> lod, y >> lod,
-        modulo((ipos.y - y) / int(u_TextureScale.y), int(u_TextureScale.w))
-    );
-    float alt = texelFetch(t_Height, tc, lod).x;
+    ivec2 tc = ivec2(x, y) >> lod;
+    float alt = texelFetch(sampler2D(t_Height, s_MainSampler), tc, lod).x;
     return alt * u_TextureScale.z;
 }
 
 // The alternative version of this routine that doesn't use
 // integer operations or `texelFetch`.
 float get_lod_height_alt(ivec2 ipos, int lod) {
     vec2 xy = (vec2(ipos.xy) + 0.5) / u_TextureScale.xy;
-    float z = trunc(mod(float(ipos.y) / u_TextureScale.y, u_TextureScale.w));
-    float alt = textureLod(t_Height, vec3(xy, z), float(lod)).x;
+    float alt = textureLod(sampler2D(t_Height, s_MainSampler), xy, float(lod)).x;
     return alt * u_TextureScale.z;
 }
 

data/shader/terrain_ray.glsl

@@ -30,6 +30,8 @@ layout(set = 1, binding = 1) uniform Locals {
 
 #define TERRAIN_WATER   0U
 
+const float c_Step = 0.6;
+
 layout(location = 0) out vec4 o_Color;
 
 vec3 cast_ray_to_plane(float level, vec3 base, vec3 dir) {

data/shader/terrain_ray_old.glsl

@@ -1,6 +1,6 @@
 //!include fs:surface.inc fs:color.inc
 
-uniform c_Globals {
+layout(set = 0, binding = 0) uniform c_Globals {
     vec4 u_CameraPos;
     mat4 u_ViewProj;
     mat4 u_InvViewProj;
@@ -11,18 +11,20 @@ uniform c_Globals {
 
 #ifdef SHADER_VS
 
-attribute vec4 a_Pos;
+layout(location = 0) attribute vec4 a_Pos;
 
 void main() {
     gl_Position = u_ViewProj * a_Pos;
+    // convert from -1,1 Z to 0,1
+    gl_Position.z = 0.5 * (gl_Position.z + gl_Position.w);
 }
 #endif //VS
 
 
 #ifdef SHADER_FS
 //imported: Surface, u_TextureScale, get_surface, evaluate_color
 
-uniform c_Locals {
+layout(set = 1, binding = 1) uniform c_Locals {
     vec4 u_ScreenSize;      // XY = size
 };
 
@@ -32,7 +34,7 @@ const float
 
 #define TERRAIN_WATER   0U
 
-out vec4 Target0;
+layout(location = 0) out vec4 o_Color;
 
 
 vec3 cast_ray_to_plane(float level, vec3 base, vec3 dir) {
@@ -85,7 +87,7 @@ Surface cast_ray_impl(
 struct CastPoint {
     vec3 pos;
     uint type;
-    vec3 tex_coord;
+    vec2 tex_coord;
     bool is_underground;
     //bool is_shadowed;
 };
@@ -180,7 +182,7 @@ void main() {
             frag_color += c_ReflectionPower * ref_color;
         }
     }
-    Target0 = frag_color;
+    o_Color = frag_color;
 
     vec4 target_ndc = u_ViewProj * vec4(pt.pos, 1.0);
     gl_FragDepth = target_ndc.z / target_ndc.w * 0.5 + 0.5;

src/render/terrain.rs

@@ -62,7 +62,7 @@ impl Context {
         layout: &wgpu::PipelineLayout,
         device: &wgpu::Device,
     ) -> wgpu::RenderPipeline {
-        let shaders = Shaders::new("terrain_ray", &[], device)
+        let shaders = Shaders::new("terrain_ray_old", &[], device)
             .unwrap();
         device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
             layout,