Create generic buffer type

src/img.c

@@ -4,31 +4,28 @@
 #include "utils.h"
 #include <stdbool.h>
 #include <stddef.h>
+#include <string.h>
 
-#define SAMPLES_PER_PIXEL 4
-
-bool init_image(Arena *arena, Image *img) {
-  if (!arena || !img || img->width == 0 || img->height == 0) {
+bool _init_buffer(Arena *arena, Buffer *buffer, u64 base_size) {
+  if (!arena || !buffer || buffer->width == 0 || buffer->height == 0) {
     return false;
   }
 
-  u64 size = img->width * img->height * SAMPLES_PER_PIXEL;
-  img->buf = wapp_mem_arena_alloc(arena, size);
+  u64 size = buffer->width * buffer->height * base_size;
+  buffer->buf = wapp_mem_arena_alloc(arena, size);
 
-  return img->buf != NULL;
+  return buffer->buf != NULL;
 }
 
-void set_pixel(Image *img, u64 x, u64 y, Colour colour) {
-  u64 idx = (y * img->width + x) * SAMPLES_PER_PIXEL;
-  for (u64 i = 0; i < SAMPLES_PER_PIXEL; ++i) {
-    img->buf[idx + i] = *(((u8 *)&colour) + i);
-  }
+void _set_pixel(Buffer *buffer, u64 x, u64 y, void *value, u64 base_size) {
+  u64 idx = (y * buffer->width + x) * base_size;
+  memcpy(((u8 *)(buffer->buf)) + idx, value, base_size);
 }
 
-void clear_image(Image *img, Colour colour) {
-  for (u64 y = 0; y < img->height; ++y) {
-    for (u64 x = 0; x < img->width; ++x) {
-      set_pixel(img, x, y, colour);
+void _clear_buffer(Buffer *buffer, void *value, u64 base_size) {
+  for (u64 y = 0; y < buffer->height; ++y) {
+    for (u64 x = 0; x < buffer->width; ++x) {
+      _set_pixel(buffer, x, y, value, base_size);
     }
   }
 }
@@ -49,7 +46,7 @@ void draw_line(Image *img, u64 x0, u64 y0, u64 x1, u64 y1, Colour colour) {
     for (u64 x = x0; x < x1; ++x) {
       t = (f32)(x - x0) / (f32)(x1 - x0);
       y = (i64)y0 + ((i64)y1 - (i64)y0) * t;
-      set_pixel(img, x, y, colour);
+      set_pixel(img, x, y, &colour);
     }
   } else {
     if (y0 > y1) {
@@ -60,11 +57,11 @@ void draw_line(Image *img, u64 x0, u64 y0, u64 x1, u64 y1, Colour colour) {
     for (u64 y = y0; y < y1; ++y) {
       t = (f32)(y - y0) / (f32)(y1 - y0);
       x = (i64)x0 + ((i64)x1 - (i64)x0) * t;
-      set_pixel(img, x, y, colour);
+      set_pixel(img, x, y, &colour);
     }
   }
 }
 
 void save_image(const Image *img, const char *filename) {
-  write_p7_image(img->width, img->height, img->buf, filename);
+  write_p7_image(img->width, img->height, (u8 *)(img->buf), filename);
 }

src/img.h

@@ -5,12 +5,12 @@
 #include "mem_arena.h"
 #include <stdbool.h>
 
-typedef struct img Image;
-struct img {
-  u64 width;
-  u64 height;
-  u8 *buf;
-};
+#define BUF_TYPE(NAME, TYPE)                                                   \
+  typedef struct {                                                             \
+    u64 width;                                                                 \
+    u64 height;                                                                \
+    TYPE *buf;                                                                 \
+  } NAME
 
 typedef struct colour Colour;
 struct colour {
@@ -20,9 +20,20 @@ struct colour {
   u8 a;
 };
 
-bool init_image(Arena *arena, Image *img);
-void set_pixel(Image *img, u64 x, u64 y, Colour colour);
-void clear_image(Image *img, Colour colour);
+BUF_TYPE(Buffer, void);
+BUF_TYPE(Image, Colour);
+BUF_TYPE(Depth, f32);
+
+#define init_buffer(ARENA, BUF)                                                \
+  _init_buffer(ARENA, (Buffer *)BUF, sizeof(*((BUF)->buf)))
+#define set_pixel(BUF, X, Y, VAL_PTR)                                          \
+  _set_pixel((Buffer *)BUF, X, Y, VAL_PTR, sizeof(*((BUF)->buf)))
+#define clear_buffer(BUF, VAL_PTR)                                             \
+  _clear_buffer((Buffer *)BUF, VAL_PTR, sizeof(*((BUF)->buf)))
+
+bool _init_buffer(Arena *arena, Buffer *buffer, u64 base_size);
+void _set_pixel(Buffer *buffer, u64 x, u64 y, void *value, u64 base_size);
+void _clear_buffer(Buffer *buffer, void *value, u64 base_size);
 void draw_line(Image *img, u64 x0, u64 y0, u64 x1, u64 y1, Colour colour);
 void save_image(const Image *img, const char *filename);
 

src/main.c

@@ -36,7 +36,7 @@ int main(void) {
     return TINY_EXIT_MODEL_LOAD_FAILED;
   }
 
-  clear_image(&(render.img), bg);
+  clear_buffer(&(render.img), &bg);
   render_model(&model, &render, teal, RENDER_TYPE_SHADED, COLOUR_TYPE_FIXED);
   save_image(&(render.img), "result.pam");
 

src/obj.c

@@ -8,6 +8,7 @@
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 
 #define TRIANGLE_VERTICES 3
 
@@ -134,13 +135,18 @@ Model load_obj_file(Arena *arena, const char *filename) {
 
 bool init_render(Arena *arena, Render *render, u64 width, u64 height) {
   render->img = (Image){.width = width, .height = height};
-  render->zbuf = (Image){.width = width, .height = height};
-
-  if (!init_image(arena, &(render->img)) ||
-      !init_image(arena, &(render->zbuf))) {
+  if (!init_buffer(arena, &(render->img))) {
     return false;
   }
 
+  render->depth = (Depth){.width = width, .height = height};
+  if (!init_buffer(arena, &(render->depth))) {
+    return false;
+  }
+
+  f32 inf = INFINITY;
+  clear_buffer(&(render->depth), &inf);
+
   return true;
 }
 
@@ -232,7 +238,7 @@ internal void fill_triangle(Render *render, Vertex vertices[TRIANGLE_VERTICES],
       if (coords.x < 0.0f || coords.y < 0.0f || coords.z < 0.0f) {
         continue;
       }
-      set_pixel(img, x, y, colour);
+      set_pixel(img, x, y, &colour);
     }
   }
 }

src/obj.h

@@ -50,7 +50,7 @@ struct model {
 typedef struct render Render;
 struct render {
   Image img;
-  Image zbuf;
+  Depth depth;
 };
 
 Model load_obj_file(Arena *arena, const char *filename);