Tweak fragment shader to take and return V4f instead of Colour

src/model/render.c

@@ -6,6 +6,7 @@
 #include "typed_list.h"
 #include "utils.h"
 #include "vec.h"
+#include <stdint.h>
 #include <math.h>
 
 typedef struct triangle_bbox TriangleBBox;
@@ -92,6 +93,8 @@ internal void fill_triangle(Render *render, ShaderID shader, VertexData vertices
   V3f            coords;
   f32            z;
   f32            zbuf;
+  V4f            shader_colour;
+  Colour         output_colour;
   FragmentResult result;
 
   f32 intensity = 1.0f;
@@ -114,13 +117,21 @@ internal void fill_triangle(Render *render, ShaderID shader, VertexData vertices
         continue;
       }
 
-      result = run_fragment_shader(shader, &coords, &colour, model);
+      shader_colour = (V4f){.r = colour.r, .g = colour.g, .b = colour.b, .a = colour.a};
+      result        = run_fragment_shader(shader, &coords, &shader_colour, model);
       if (DISCARD_FRAGMENT(result)) {
         continue;
       }
 
+      output_colour = (Colour){
+          .r = clamp(result.colour.r, 0, UINT8_MAX),
+          .g = clamp(result.colour.g, 0, UINT8_MAX),
+          .b = clamp(result.colour.b, 0, UINT8_MAX),
+          .a = clamp(result.colour.a, 0, UINT8_MAX),
+      };
+
       set_pixel(depth, x, y, &z);
-      set_pixel(img, x, y, &result.colour);
+      set_pixel(img, x, y, &output_colour);
     }
   }
 }

src/shader/depth_shader.c

@@ -1,8 +1,5 @@
 #include "depth_shader.h"
-#include "constants.h"
-#include "img.h"
 #include "shader.h"
-#include "utils.h"
 
 VertexData depth_shader_vertex(void *shader, const VertexData *vert, u8 index, const Model *model) {
   DepthShader *shdr = (DepthShader *)shader;
@@ -15,7 +12,7 @@ VertexData depth_shader_vertex(void *shader, const VertexData *vert, u8 index, c
   return shdr->vertices[index];
 }
 
-FragmentResult depth_shader_fragment(void *shader, const V3f *barycentric, const Colour *colour,
+FragmentResult depth_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
                                      const Model *model) {
   DepthShader *shdr = (DepthShader *)shader;
 
@@ -23,8 +20,7 @@ FragmentResult depth_shader_fragment(void *shader, const V3f *barycentric, const
   pos_mat       = mat3x3_transpose(pos_mat);
 
   V3f position = mat3x3_mul_vec3(pos_mat, (*barycentric));
-  f32    channel  = clamp(position.z + DEPTH_MAX, 0.0f, DEPTH_MAX);
+  V4f output   = {.r = position.z, .g = position.z, .b = position.z, .a = 255};
-  Colour output   = {.r = (u8)(channel), .g = (u8)(channel), .b = (u8)(channel), .a = 255};
 
   return (FragmentResult){.colour = output};
 }

src/shader/depth_shader.h

@@ -11,7 +11,7 @@ struct depth_shader {
 };
 
 VertexData     depth_shader_vertex(void *shader, const VertexData *vert, u8 index, const Model *model);
-FragmentResult depth_shader_fragment(void *shader, const V3f *barycentric, const Colour *colour,
+FragmentResult depth_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
                                      const Model *model);
 
 #endif // !DEPTH_SHADER_H

src/shader/main_shader.c

@@ -1,4 +1,5 @@
 #include "main_shader.h"
+#include "img.h"
 #include "obj.h"
 #include "shader.h"
 #include "utils.h"
@@ -23,7 +24,7 @@ VertexData general_shader_vertex(void *shader, const VertexData *vert, u8 index,
   return shdr->vertices[index];
 }
 
-FragmentResult diffuse_shader_fragment(void *shader, const V3f *barycentric, const Colour *colour,
+FragmentResult diffuse_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
                                        const Model *model) {
   Shader *shdr = (Shader *)shader;
 
@@ -81,11 +82,12 @@ FragmentResult diffuse_shader_fragment(void *shader, const V3f *barycentric, con
   }
 #pragma endregion darboux_frame_tangent_normals
 
-  Colour output;
+  V4f output;
   if (model->texture) {
     u64    tx_x = uv.u * model->texture->width;
     u64    tx_y = uv.v * model->texture->height;
-    output   = get_pixel(Colour, model->texture, tx_x, tx_y);
+    Colour tx   = get_pixel(Colour, model->texture, tx_x, tx_y);
+    output      = (V4f){.r = tx.r, .g = tx.g, .b = tx.b, .a = tx.a};
   } else {
     output = *colour;
   }
@@ -102,7 +104,7 @@ FragmentResult diffuse_shader_fragment(void *shader, const V3f *barycentric, con
   return (FragmentResult){.colour = output};
 }
 
-FragmentResult albedo_shader_fragment(void *shader, const V3f *barycentric, const Colour *colour,
+FragmentResult albedo_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
                                       const Model *model) {
   Shader *shdr = (Shader *)shader;
 
@@ -110,11 +112,12 @@ FragmentResult albedo_shader_fragment(void *shader, const V3f *barycentric, cons
   M2x3f uv_mat = mat3x2_transpose(uvs);
   V2f   uv     = mat2x3_mul_vec3(uv_mat, (*barycentric));
 
-  Colour output;
+  V4f output;
   if (model->texture) {
     u64    tx_x = uv.u * model->texture->width;
     u64    tx_y = uv.v * model->texture->height;
-    output   = get_pixel(Colour, model->texture, tx_x, tx_y);
+    Colour tx   = get_pixel(Colour, model->texture, tx_x, tx_y);
+    output      = (V4f){.r = tx.r, .g = tx.g, .b = tx.b, .a = tx.a};
   } else {
     output = *colour;
   }

src/shader/main_shader.h

@@ -10,8 +10,8 @@ struct shader {
 };
 
 VertexData     general_shader_vertex(void *shader, const VertexData *vert, u8 index, const Model *model);
-FragmentResult diffuse_shader_fragment(void *shader, const V3f *barycentric, const Colour *colour,
+FragmentResult diffuse_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
                                        const Model *model);
-FragmentResult albedo_shader_fragment(void *shader, const V3f *barycentric, const Colour *colour,
+FragmentResult albedo_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
                                       const Model *model);
 #endif // !MAIN_SHADER_H

src/shader/shader.c

@@ -41,7 +41,7 @@ VertexData run_vertex_shader(ShaderID shader, const VertexData *vert, u8 index,
   return vertex_func(shader_obj, vert, index, model);
 }
 
-FragmentResult run_fragment_shader(ShaderID shader, const V3f *barycentric, const Colour *colour,
+FragmentResult run_fragment_shader(ShaderID shader, const V3f *barycentric, const V4f *colour,
                                    const Model *model) {
   if (IS_INVALID_SHADER(shader) || shader.id > g_repository.count || !colour) {
     return DISCARDED_FRAGMENT;

src/shader/shader.h

@@ -2,7 +2,6 @@
 #define SHADER_H
 
 #include "aliases.h"
-#include "img.h"
 #include "obj.h"
 #include "vec.h"
 
@@ -20,7 +19,7 @@ struct vertex_data {
 
 typedef struct fragment_result FragmentResult;
 struct fragment_result {
-  Colour colour;
+  V4f  colour;
   bool discard;
 };
 
@@ -30,11 +29,11 @@ struct fragment_result {
 #define DISCARD_FRAGMENT(RESULT) (RESULT.discard)
 
 typedef VertexData(VertexShader)(void *shader, const VertexData *vert, u8 index, const Model *model);
-typedef FragmentResult(FragmentShader)(void *shader, const V3f *barycentric, const Colour *colour,
+typedef FragmentResult(FragmentShader)(void *shader, const V3f *barycentric, const V4f *colour,
                                        const Model *model);
 
 ShaderID register_shader(void *shader, VertexShader *vertex, FragmentShader *fragment);
 VertexData run_vertex_shader(ShaderID shader, const VertexData *vert, u8 index, const Model *model);
-FragmentResult run_fragment_shader(ShaderID shader, const V3f *barycentric, const Colour *colour, const Model *model);
+FragmentResult run_fragment_shader(ShaderID shader, const V3f *barycentric, const V4f *colour, const Model *model);
 
 #endif // SHADER_H

src/vec/vec.h

@@ -55,10 +55,22 @@ typedef union f32x4 V4f;
 union f32x4 {
   f32 elements[4];
   struct {
+    union {
       f32 x;
+      f32 r;
+    };
+    union {
       f32 y;
+      f32 g;
+    };
+    union {
       f32 z;
+      f32 b;
+    };
+    union {
       f32 w;
+      f32 a;
+    };
   };
 };