Reformat

.gitignore

@@ -1,6 +1,6 @@
 .cache
 compile_commands.json
-tiny
+/tiny
 *.pam
 resources/*.png
 .venv

src/main.c

@@ -1,113 +1,6 @@
-#include "img.h"
-#include "mem_arena.h"
-#include "misc_utils.h"
-#include "obj.h"
-#include "render.h"
-#include "shaders.h"
-#include "str.h"
-#include "vec.h"
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/stat.h>
-#include <time.h>
+#include "aliases.h"
+#include "tiny.h"
 
-#define IMAGE_DIMENSION 1200
-
-enum {
-  TINY_EXIT_SUCCESS,
-  TINY_EXIT_MISSING_ARGS,
-  TINY_EXIT_OBJ_NOT_EXIST,
-  TINY_EXIT_ARENA_INIT_FAILED,
-  TINY_EXIT_RENDER_INIT_FAILED,
-  TINY_EXIT_MODEL_LOAD_FAILED,
-};
-
-typedef struct tiny_args TinyArgs;
-struct tiny_args {
-  Str8 obj;
-  Str8 diffuse;
-  Str8 tangent;
-};
-
-internal TinyArgs parse_args(Arena *arena, int argc, char *argv[]);
-internal i32      tinyrenderer(Arena *arena, TinyArgs args);
-internal bool     file_exists(const Str8 *path);
-
-i32 main(int argc, char *argv[]) {
-  Arena *arena = NULL;
-  if (!wapp_mem_arena_init(&arena, GB(10))) {
-    return TINY_EXIT_ARENA_INIT_FAILED;
-  }
-
-  TinyArgs args   = parse_args(arena, argc, argv);
-  i32      output = tinyrenderer(arena, args);
-
-  wapp_mem_arena_destroy(&arena);
-
-  return output;
-}
-
-internal TinyArgs parse_args(Arena *arena, int argc, char *argv[]) {
-  if (argc < 2) {
-    exit(TINY_EXIT_MISSING_ARGS);
-  }
-
-  TinyArgs args = {
-      .obj = str8_lit(argv[1]),
-  };
-
-  if (!file_exists(&args.obj)) {
-    exit(TINY_EXIT_OBJ_NOT_EXIST);
-  }
-
-  u64 substr_end = args.obj.length - 4;
-
-  args.diffuse = str8_substr(arena, &args.obj, 0, substr_end);
-  str8_concat(arena, &args.diffuse, "_diffuse.pnm");
-  if (!file_exists(&args.diffuse)) {
-    args.diffuse = (Str8){0};
-  }
-
-  args.tangent = str8_substr(arena, &args.obj, 0, substr_end);
-  str8_concat(arena, &args.tangent, "_tangent.pnm");
-  if (!file_exists(&args.tangent)) {
-    args.tangent = (Str8){0};
-  }
-
-  return args;
-}
-
-internal i32 tinyrenderer(Arena *arena, TinyArgs args) {
-  Colour bg          = {.r = 42, .g = 45,  .b = 52,  .a = 255};
-  Colour main_colour = {.r = 14, .g = 156, .b = 208, .a = 255};
-
-  Render render;
-  if (!init_render(arena, &render, IMAGE_DIMENSION, IMAGE_DIMENSION)) {
-    return TINY_EXIT_RENDER_INIT_FAILED;
-  }
-
-  const char *diffuse = args.diffuse.length > 0 ? args.diffuse.str : NULL;
-  const char *tangent = args.tangent.length > 0 ? args.tangent.str : NULL;
-
-  Model obj = load_obj_file(arena, args.obj.str, diffuse, tangent);
-  if (IS_INVALID_MODEL(obj)) {
-    return TINY_EXIT_MODEL_LOAD_FAILED;
-  }
-
-  load_shaders(viewport(0, 0, IMAGE_DIMENSION, IMAGE_DIMENSION));
-
-  clear_buffer(&(render.img), &bg);
-
-  // render_model(&obj, &render, depth, RENDER_TYPE_SHADED, main_colour);
-  render_model(&obj, &render, perspective_diffuse, RENDER_TYPE_SHADED, main_colour);
-  save_image(&(render.img), "result.pam");
-
-  return TINY_EXIT_SUCCESS;
-}
-
-internal bool file_exists(const Str8 *path) {
-  struct stat st;
-  return stat(path->str, &st) == 0;
+i32 main(i32 argc, char *argv[]) {
+  return tiny_main(argc, argv);
 }

src/model/render.c

@@ -9,6 +9,8 @@
 #include <stdint.h>
 #include <math.h>
 
+Render g_render_passes[COUNT_RENDER_PASS] = {0};
+
 typedef struct triangle_bbox TriangleBBox;
 struct triangle_bbox {
   u64 x0;
@@ -42,8 +44,7 @@ bool init_render(Arena *arena, Render *render, u64 width, u64 height) {
   return true;
 }
 
-void render_model(const Model *model, Render *render, ShaderID shader,
-                  RenderType render_type, Colour colour) {
+void render_model(const Model *model, Render *render, ShaderID shader, RenderType render_type, Colour colour) {
   Triangle triangle;
   for (u64 i = 0; i < model->triangles->count; ++i) {
     triangle = list_get(model->triangles, i);
@@ -79,8 +80,8 @@ internal void render_triangle(const Triangle *triangle, const Model *model, Shad
 
 internal void fill_triangle(Render *render, ShaderID shader, VertexData vertices[TRIANGLE_VERTICES],
                             Colour colour, const Model *model, RenderType type) {
-  Image *img   = &(render->img);
-  Depth *depth = &(render->depth);
+  Image   *img   = &(render->img);
+  Depth   *depth = &(render->depth);
 
   V2f vp_verts[TRIANGLE_VERTICES] = {0};
   for (u64 i = 0; i < TRIANGLE_VERTICES; ++i) {

src/model/render.h

@@ -5,14 +5,13 @@
 #include "mem_arena.h"
 #include "obj.h"
 #include "shader.h"
-#include <stdbool.h>
 
 typedef enum {
   RENDER_TYPE_WIREFRAME,
   RENDER_TYPE_FILLED,
   RENDER_TYPE_SHADED,
 
-  COUNT_RENDER_TYPES,
+  COUNT_RENDER_TYPE,
 } RenderType;
 
 typedef enum {
@@ -28,8 +27,16 @@ struct render {
   Depth depth;
 };
 
+enum render_pass {
+  RENDER_PASS_SHADOW,
+  RENDER_PASS_MAIN,
+
+  COUNT_RENDER_PASS,
+};
+
+extern Render g_render_passes[COUNT_RENDER_PASS];
+
 bool init_render(Arena *arena, Render *render, u64 width, u64 height);
-void render_model(const Model *model, Render *render, ShaderID shader,
-                  RenderType render_type, Colour colour);
+void render_model(const Model *model, Render *render, ShaderID shader, RenderType render_type, Colour colour);
 
 #endif // RENDER_H

src/shader/depth_shader.c

@@ -1,26 +0,0 @@
-#include "depth_shader.h"
-#include "shader.h"
-
-VertexData depth_shader_vertex(void *shader, const VertexData *vert, u8 index, const Model *model) {
-  DepthShader *shdr = (DepthShader *)shader;
-
-  V4f vh = V3_to_V4(vert->position);
-  vh.y   = 0.0 - vh.y;
-  vh     = mat4x4_mul_vec4(shdr->final, vh);
-  shdr->vertices[index].position = project_vec4(vh);
-
-  return shdr->vertices[index];
-}
-
-FragmentResult depth_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
-                                     const Model *model) {
-  DepthShader *shdr = (DepthShader *)shader;
-
-  M3x3f pos_mat = {.rows = {shdr->vertices[0].position, shdr->vertices[1].position, shdr->vertices[2].position}};
-  pos_mat       = mat3x3_transpose(pos_mat);
-
-  V3f position = mat3x3_mul_vec3(pos_mat, (*barycentric));
-  V4f output   = {.r = position.z, .g = position.z, .b = position.z, .a = 255};
-
-  return (FragmentResult){.colour = output};
-}

src/shader/depth_shader.h

@@ -1,17 +0,0 @@
-#ifndef DEPTH_SHADER_H
-#define DEPTH_SHADER_H
-
-#include "constants.h"
-#include "shader.h"
-#include "vec.h"
-
-typedef struct depth_shader DepthShader;
-struct depth_shader {
-#include "shader_base.inc"
-};
-
-VertexData     depth_shader_vertex(void *shader, const VertexData *vert, u8 index, const Model *model);
-FragmentResult depth_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
-                                     const Model *model);
-
-#endif // !DEPTH_SHADER_H

src/shader/main_shader.c

@@ -1,6 +1,7 @@
 #include "main_shader.h"
 #include "img.h"
 #include "obj.h"
+#include "render.h"
 #include "shader.h"
 #include "utils.h"
 #include "vec.h"
@@ -15,9 +16,8 @@ VertexData general_shader_vertex(void *shader, const VertexData *vert, u8 index,
   shdr->vertices[index].position = project_vec4(vh);
   shdr->vertices[index].uv       = vert->uv;
 
-  M4x4f inv_transpose          = mat4x4_inv(mat4x4_transpose(shdr->proj_mv));
   V4f hnorm                    = V3_to_V4(vert->normal);
-  hnorm                        = mat4x4_mul_vec4(inv_transpose, hnorm);
+  hnorm                        = mat4x4_mul_vec4(shdr->proj_mv_inv_t, hnorm);
   shdr->vertices[index].normal = project_vec4(hnorm);
   normalise_v3(shdr->vertices[index].normal);
 
@@ -39,6 +39,15 @@ FragmentResult diffuse_shader_fragment(void *shader, const V3f *barycentric, con
   V3f normal   = mat3x3_mul_vec3(normal_mat, (*barycentric));
   V2f uv       = mat2x3_mul_vec3(uv_mat, (*barycentric));
 
+  V4f shadow_position_h = V3_to_V4(position);
+  shadow_position_h     = mat4x4_mul_vec4(shdr->shadow_matrix, shadow_position_h);
+  V3f shadow_position   = project_vec4(shadow_position_h);
+
+  // Calculate shadow
+  const Render *shadow_pass = &(g_render_passes[RENDER_PASS_SHADOW]);
+  f32 shadow_z              = get_pixel(f32, &(shadow_pass->depth), shadow_position.x, shadow_position.y);
+  f32 shadow                = 0.3f + 0.7f * (shadow_z < shadow_position.z + 10.0f);
+
 #pragma region darboux_frame_tangent_normals
   /**
    * Based on the following section of the tinyrenderer tutorial
@@ -97,9 +106,9 @@ FragmentResult diffuse_shader_fragment(void *shader, const V3f *barycentric, con
   f32 g         = clamp(intensity + shdr->ambient.g, 0.0f, 1.0f);
   f32 b         = clamp(intensity + shdr->ambient.b, 0.0f, 1.0f);
 
-  output.r *= r;
-  output.g *= g;
-  output.b *= b;
+  output.r *= r * shadow;
+  output.g *= g * shadow;
+  output.b *= b * shadow;
 
   return (FragmentResult){.colour = output};
 }

src/shader/main_shader.h

@@ -6,7 +6,8 @@
 
 typedef struct shader Shader;
 struct shader {
-#include "shader_base.inc"
+  #include "shader_base.inc"
+  M4x4f shadow_matrix;
 };
 
 VertexData     general_shader_vertex(void *shader, const VertexData *vert, u8 index, const Model *model);

src/shader/shader_base.inc

@@ -4,4 +4,5 @@ M4x4f proj_mv;
 M4x4f proj_mv_inv_t;
 M4x4f viewport;
 M4x4f final;
+M4x4f final_inv;
 VertexData vertices[TRIANGLE_VERTICES];

src/shader/shaders.c

@@ -1,20 +1,20 @@
 #include "shaders.h"
 #include "aliases.h"
-#include "depth_shader.h"
+#include "shadow_shader.h"
 #include "main_shader.h"
 #include "render.h"
 #include "shader.h"
 #include "vec.h"
 
+ShaderID depth                = {0};
 ShaderID perspective_diffuse  = {0};
 ShaderID perspective_albedo   = {0};
 ShaderID orthographic_diffuse = {0};
 ShaderID orthographic_albedo  = {0};
-ShaderID depth                = {0};
 
-internal Shader      perspective  = {0};
-internal Shader      orthographic = {0};
-internal DepthShader depth_shader = {0};
+internal ShadowShader depth_shader = {0};
+internal Shader       perspective  = {0};
+internal Shader       orthographic = {0};
 
 internal V3f g_ambient_light = {0.1f, 0.1f, 0.1f};
 internal V3f g_eye           = {0.2f, -0.1f, 0.5f};
@@ -25,6 +25,19 @@ internal V3f g_light_dir     = {1.0f, -1.0f, 1.0f};
 internal M4x4f get_projection_matrix(ProjectionType projection_type);
 
 void load_shaders(M4x4f vp) {
+  // Set up depth shader matrices
+  M4x4f depth_model_view = lookat(g_light_dir, g_target, g_up);
+  M4x4f depth_projection = projection(0.0f);
+
+  // Set up depth shader
+  depth_shader.proj_mv       = mat4x4_mul(depth_projection, depth_model_view);
+  depth_shader.proj_mv_inv_t = mat4x4_inv(mat4x4_transpose(depth_shader.proj_mv));
+  depth_shader.viewport      = vp;
+  depth_shader.final         = mat4x4_mul(depth_shader.viewport, depth_shader.proj_mv);
+  depth_shader.light_dir     = mat3x3_mul_vec3(depth_shader.proj_mv, g_light_dir);
+  normalise_v3(depth_shader.light_dir);
+
+  // Set up main shader matrices
   M4x4f model_view              = lookat(g_eye, g_target, g_up);
   M4x4f orthographic_projection = get_projection_matrix(PROJECTION_TYPE_ORTHOGRAPHIC);
   M4x4f perspective_projection  = get_projection_matrix(PROJECTION_TYPE_PERSPECTIVE);
@@ -34,36 +47,29 @@ void load_shaders(M4x4f vp) {
   perspective.proj_mv_inv_t = mat4x4_inv(mat4x4_transpose(perspective.proj_mv));
   perspective.viewport      = vp;
   perspective.final         = mat4x4_mul(perspective.viewport, perspective.proj_mv);
+  perspective.final_inv     = mat4x4_inv(perspective.final);
+  perspective.ambient       = g_ambient_light;
   perspective.light_dir     = mat3x3_mul_vec3(perspective.proj_mv, g_light_dir);
   normalise_v3(perspective.light_dir);
-  perspective.ambient       = g_ambient_light;
+  perspective.shadow_matrix = mat4x4_mul(depth_shader.final, perspective.final_inv);
 
   // Set up orthographic shader
   orthographic.proj_mv       = mat4x4_mul(orthographic_projection, model_view);
   orthographic.proj_mv_inv_t = mat4x4_inv(mat4x4_transpose(orthographic.proj_mv));
   orthographic.viewport      = vp;
   orthographic.final         = mat4x4_mul(orthographic.viewport, orthographic.proj_mv);
+  orthographic.final_inv     = mat4x4_inv(perspective.final);
+  orthographic.shadow_matrix = mat4x4_mul(depth_shader.final, orthographic.final_inv);
   orthographic.light_dir     = mat3x3_mul_vec3(orthographic.proj_mv, g_light_dir);
   normalise_v3(orthographic.light_dir);
   orthographic.ambient       = g_ambient_light;
 
-  // Set up depth shader
-  M4x4f depth_model_view = lookat(g_light_dir, g_target, g_up);
-  M4x4f depth_projection = projection(0.0f);
-
-  depth_shader.proj_mv       = mat4x4_mul(depth_projection, depth_model_view);
-  depth_shader.proj_mv_inv_t = mat4x4_inv(mat4x4_transpose(depth_shader.proj_mv));
-  depth_shader.viewport      = vp;
-  depth_shader.final         = mat4x4_mul(depth_shader.viewport, depth_shader.proj_mv);
-  depth_shader.light_dir     = mat3x3_mul_vec3(depth_shader.proj_mv, g_light_dir);
-  normalise_v3(depth_shader.light_dir);
-
   // Register shaders
-  perspective_diffuse  = register_shader(&perspective, general_shader_vertex, diffuse_shader_fragment);
-  perspective_albedo   = register_shader(&perspective, general_shader_vertex, albedo_shader_fragment);
+  depth                = register_shader(&depth_shader, shadow_shader_vertex,  shadow_shader_fragment);
+  perspective_diffuse  = register_shader(&perspective,  general_shader_vertex, diffuse_shader_fragment);
+  perspective_albedo   = register_shader(&perspective,  general_shader_vertex, albedo_shader_fragment);
   orthographic_diffuse = register_shader(&orthographic, general_shader_vertex, diffuse_shader_fragment);
   orthographic_albedo  = register_shader(&orthographic, general_shader_vertex, albedo_shader_fragment);
-  depth                = register_shader(&depth_shader, depth_shader_vertex, depth_shader_fragment);
 }
 
 internal M4x4f get_projection_matrix(ProjectionType projection_type) {

src/shader/shaders.h

@@ -3,11 +3,11 @@
 
 #include "shader.h"
 
+extern ShaderID depth;
 extern ShaderID perspective_diffuse;
 extern ShaderID perspective_albedo;
 extern ShaderID orthographic_diffuse;
 extern ShaderID orthographic_albedo;
-extern ShaderID depth;
 
 void load_shaders(M4x4f vp);
 

src/shader/shadow_shader.c

@@ -0,0 +1,30 @@
+#include "shadow_shader.h"
+#include "constants.h"
+#include "shader.h"
+#include "utils.h"
+
+VertexData shadow_shader_vertex(void *shader, const VertexData *vert, u8 index, const Model *model) {
+  ShadowShader *shdr = (ShadowShader *)shader;
+
+  V4f vh = V3_to_V4(vert->position);
+  vh.y   = 0.0 - vh.y;
+  vh     = mat4x4_mul_vec4(shdr->final, vh);
+
+  shdr->vertices[index].position = project_vec4(vh);
+
+  return shdr->vertices[index];
+}
+
+FragmentResult shadow_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
+                                     const Model *model) {
+  ShadowShader *shdr = (ShadowShader *)shader;
+
+  M3x3f pos_mat = {.rows = {shdr->vertices[0].position, shdr->vertices[1].position, shdr->vertices[2].position}};
+  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 = channel, .g = channel, .b = channel, .a = 255};
+
+  return (FragmentResult){.colour = output};
+}

src/shader/shadow_shader.h

@@ -0,0 +1,17 @@
+#ifndef SHADOW_SHADER_H
+#define SHADOW_SHADER_H
+
+#include "constants.h"
+#include "shader.h"
+#include "vec.h"
+
+typedef struct shadow_shader ShadowShader;
+struct shadow_shader {
+  #include "shader_base.inc"
+};
+
+VertexData     shadow_shader_vertex(void *shader, const VertexData *vert, u8 index, const Model *model);
+FragmentResult shadow_shader_fragment(void *shader, const V3f *barycentric, const V4f *colour,
+                                      const Model *model);
+
+#endif // !SHADOW_SHADER_H

src/tiny/tiny.c

@@ -0,0 +1,116 @@
+#include "img.h"
+#include "mem_arena.h"
+#include "misc_utils.h"
+#include "obj.h"
+#include "render.h"
+#include "shaders.h"
+#include "str.h"
+#include "vec.h"
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <time.h>
+
+#define IMAGE_DIMENSION 1200
+
+enum {
+  TINY_EXIT_SUCCESS,
+  TINY_EXIT_MISSING_ARGS,
+  TINY_EXIT_OBJ_NOT_EXIST,
+  TINY_EXIT_ARENA_INIT_FAILED,
+  TINY_EXIT_RENDER_INIT_FAILED,
+  TINY_EXIT_MODEL_LOAD_FAILED,
+};
+
+typedef struct tiny_args TinyArgs;
+struct tiny_args {
+  Str8 obj;
+  Str8 diffuse;
+  Str8 tangent;
+};
+
+internal TinyArgs parse_args(Arena *arena, int argc, char *argv[]);
+internal i32      tinyrenderer(Arena *arena, TinyArgs args);
+internal bool     file_exists(const Str8 *path);
+
+i32 tiny_main(i32 argc, char *argv[]) {
+  Arena *arena = NULL;
+  if (!wapp_mem_arena_init(&arena, GB(10))) {
+    return TINY_EXIT_ARENA_INIT_FAILED;
+  }
+
+  TinyArgs args   = parse_args(arena, argc, argv);
+  i32      output = tinyrenderer(arena, args);
+
+  wapp_mem_arena_destroy(&arena);
+
+  return output;
+}
+
+internal TinyArgs parse_args(Arena *arena, int argc, char *argv[]) {
+  if (argc < 2) {
+    exit(TINY_EXIT_MISSING_ARGS);
+  }
+
+  TinyArgs args = {
+      .obj = str8_lit(argv[1]),
+  };
+
+  if (!file_exists(&args.obj)) {
+    exit(TINY_EXIT_OBJ_NOT_EXIST);
+  }
+
+  u64 substr_end = args.obj.length - 4;
+
+  args.diffuse = str8_substr(arena, &args.obj, 0, substr_end);
+  str8_concat(arena, &args.diffuse, "_diffuse.pnm");
+  if (!file_exists(&args.diffuse)) {
+    args.diffuse = (Str8){0};
+  }
+
+  args.tangent = str8_substr(arena, &args.obj, 0, substr_end);
+  str8_concat(arena, &args.tangent, "_tangent.pnm");
+  if (!file_exists(&args.tangent)) {
+    args.tangent = (Str8){0};
+  }
+
+  return args;
+}
+
+internal i32 tinyrenderer(Arena *arena, TinyArgs args) {
+  Colour bg          = {.r = 42, .g = 45,  .b = 52,  .a = 255};
+  Colour main_colour = {.r = 14, .g = 156, .b = 208, .a = 255};
+
+  Render *shadowbuffer = &(g_render_passes[RENDER_PASS_SHADOW]);
+  Render *framebuffer  = &(g_render_passes[RENDER_PASS_MAIN]);
+  if (!init_render(arena, shadowbuffer, IMAGE_DIMENSION, IMAGE_DIMENSION) ||
+      !init_render(arena, framebuffer,  IMAGE_DIMENSION, IMAGE_DIMENSION)) {
+    return TINY_EXIT_RENDER_INIT_FAILED;
+  }
+
+  const char *diffuse = args.diffuse.length > 0 ? args.diffuse.str : NULL;
+  const char *tangent = args.tangent.length > 0 ? args.tangent.str : NULL;
+
+  Model obj = load_obj_file(arena, args.obj.str, diffuse, tangent);
+  if (IS_INVALID_MODEL(obj)) {
+    return TINY_EXIT_MODEL_LOAD_FAILED;
+  }
+
+  load_shaders(viewport(0, 0, IMAGE_DIMENSION, IMAGE_DIMENSION));
+
+  clear_buffer(&(framebuffer->img), &bg);
+
+  render_model(&obj, shadowbuffer, depth,               RENDER_TYPE_SHADED, main_colour);
+  render_model(&obj, framebuffer,  perspective_diffuse, RENDER_TYPE_SHADED, main_colour);
+
+  save_image(&(framebuffer->img), "result.pam");
+
+  return TINY_EXIT_SUCCESS;
+}
+
+internal bool file_exists(const Str8 *path) {
+  struct stat st;
+  return stat(path->str, &st) == 0;
+}

src/tiny/tiny.h

@@ -0,0 +1,8 @@
+#ifndef TINY_H
+#define TINY_H
+
+#include "aliases.h"
+
+i32 tiny_main(i32 argc, char *argv[]);
+
+#endif // !TINY_H

src/vec/vec.h

@@ -135,6 +135,35 @@ MAKE_LIST_TYPE(V2f);
 
 #define dot_v2(V1, V2) ((f32)V1.x * (f32)V2.x + (f32)V1.y * (f32)V2.y)
 
+#define add_v2(V1, V2)                                                         \
+  ((V2f){                                                                      \
+      .x = V1.x + V2.x,                                                        \
+      .y = V1.y + V2.y,                                                        \
+  })
+
+#define sub_v2(V1, V2)                                                         \
+  ((V2f){                                                                      \
+      .x = V1.x - V2.x,                                                        \
+      .y = V1.y - V2.y,                                                        \
+  })
+
+#define mul_v2(V1, V2)                                                         \
+  ((V2f){                                                                      \
+      .x = V1.x * V2.x,                                                        \
+      .y = V1.y * V2.y,                                                        \
+  })
+
+#define num_mul_v2(V, N) ((V2f){.x = (N) * V.x, .y = (N) * V.y})
+
+#define magnitude_v2(V) (sqrtf(dot_v2(V, V)))
+
+#define normalise_v2(V)                                                        \
+  do {                                                                         \
+    f32 magnitude = magnitude_v2(V);                                           \
+    V.x /= magnitude;                                                          \
+    V.y /= magnitude;                                                          \
+  } while (0)
+
 #define dot_v3(V1, V2)                                                         \
   ((f32)V1.x * (f32)V2.x + (f32)V1.y * (f32)V2.y + (f32)V1.z * (f32)V2.z)