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;
@@ -51,7 +52,7 @@ void render_model(const Model *model, Render *render, ShaderID shader,
 }
 
 internal void render_triangle(const Triangle *triangle, const Model *model, ShaderID shader,
-															Render *render, RenderType render_type, Colour colour) {
+                              Render *render, RenderType render_type, Colour colour) {
   Image *img = &(render->img);
   VertexData vertices[TRIANGLE_VERTICES];
   for (u64 i = 0; i < TRIANGLE_VERTICES; ++i) {
@@ -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);
     }
   }
 }