Add render_object function

include/rasteriser/rasteriser.h

@@ -2,12 +2,23 @@
 #define RASTERISER_H
 
 #include "aliases.h"
+#include "camera/camera.h"
 #include "list/typed_list.h"
 #include "mem_arena.h"
 #include "vector/vec.h"
 #include "window/window.h"
 
+typedef struct {
+  u64 idx0;
+  u64 idx1;
+  u64 idx2;
+  colour_t colour;
+} scene_triangle_t;
+
 MAKE_LIST_TYPE(f32);
+MAKE_LIST_TYPE(vec2i_t);
+MAKE_LIST_TYPE(vec3f_t);
+MAKE_LIST_TYPE(scene_triangle_t);
 
 typedef struct {
   vec2i_t p0;
@@ -24,6 +35,9 @@ typedef struct {
   colour_t colour;
 } triangle_t;
 
+void render_object(window_t *wnd, Arena *arena, const camera_t *camera,
+                   vec3f_t viewport, const list_vec3f_t *vertices,
+                   const list_scene_triangle_t *triangles);
 void draw_wireframe_triangle(window_t *wnd, Arena *arena, triangle_t triangle);
 void draw_filled_triangle(window_t *wnd, Arena *arena, triangle_t triangle);
 void draw_shaded_triangle(window_t *wnd, Arena *arena, triangle_t triangle);

src/rasteriser/rasteriser.c

@@ -15,6 +15,37 @@ internal list_float *interpolate(Arena *arena, i32 i0, f32 d0, i32 i1, f32 d1);
 
 internal inline void order_triangle_points(triangle_t *triangle);
 
+void render_object(window_t *wnd, Arena *arena, const camera_t *camera,
+                   vec3f_t viewport, const list_vec3f_t *vertices,
+                   const list_scene_triangle_t *triangles) {
+  list_vec2i_t *projected = list_create_with_capacity(
+      vec2i_t, arena, vertices->count * sizeof(vec3f_t));
+  if (!projected) {
+    return;
+  }
+
+  vec3f_t vertex = {0};
+  for (u64 i = 0; i < vertices->count; ++i) {
+    vertex = list_get(vertices, i);
+    list_append(vec2i_t, arena, projected,
+                project_point(vertex, wnd, camera, viewport));
+  }
+
+  for (u64 i = 0; i < triangles->count; ++i) {
+    scene_triangle_t triangle = list_get(triangles, i);
+    triangle_t tri = {
+        .p0 = list_get(projected, triangle.idx0),
+        .p1 = list_get(projected, triangle.idx1),
+        .p2 = list_get(projected, triangle.idx2),
+        .h0 = 1.0f,
+        .h1 = 1.0f,
+        .h2 = 1.0f,
+        .colour = triangle.colour,
+    };
+    draw_wireframe_triangle(wnd, arena, tri);
+  }
+}
+
 void draw_wireframe_triangle(window_t *wnd, Arena *arena, triangle_t triangle) {
   order_triangle_points(&triangle);