From d38ce455afd950ef82ea1a296a9e6318d0cbac2d Mon Sep 17 00:00:00 2001
From: Tyrel Souza <tyrel@tyrelsouza.com>
Date: Sat, 13 Apr 2024 00:51:28 -0400
Subject: [PATCH] add a cube

---
 Makefile   |   5 +-
 src/main.c | 135 +++++++++++++++++++++++++++--------------------------
 2 files changed, 71 insertions(+), 69 deletions(-)

diff --git a/Makefile b/Makefile
index 5a7f6c0..3700046 100644
--- a/Makefile
+++ b/Makefile
@@ -2,11 +2,10 @@ SRCS = $(shell find ./src -type f -name *.c)
 
 build:
 	gcc -Wall -std=c99 $(SRCS) -lSDL2 -o renderer
+	./renderer
 
 run: build
 	./renderer
 
 clean:
-	rm renderer
-
-all: clean build run
+	rm renderer
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index 7b82d17..ca5944c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -10,102 +10,105 @@
 #define N_POINTS  (9 * 9 * 9)
 vec3_t cube_points[N_POINTS];
 vec2_t projected_points[N_POINTS];
-float fov_factor = 128;
+
+vec3_t camera_position = {0, 0, -5};
+float fov_factor = 640;
 
 
 bool is_running = false;
 
 void setup(void) {
-  // Allocate the required memory in bytes to hold color buffer
-  color_buffer = (uint32_t *) malloc(sizeof(uint32_t) * window_width * window_height);
+	// Allocate the required memory in bytes to hold color buffer
+	color_buffer = (uint32_t *) malloc(sizeof(uint32_t) * window_width * window_height);
 
-  // Creating the SDL Texture that is uses to display the color buffer
-  color_buffer_texture = SDL_CreateTexture(
-    renderer,
-    SDL_PIXELFORMAT_ARGB8888,
-    SDL_TEXTUREACCESS_STREAMING,
-    window_width,
-    window_height
-  );
-  int point_count = 0;
-  for (float x = -1; x <= 1; x += 0.25) {
-    for (float y = -1; y <= 1; y += 0.25) {
-      for (float z = -1; z <= 1; z += 0.25) {
-        vec3_t new_point = { .x = x, .y = y, .z = z };
-        cube_points[point_count++] = new_point;
-      }
-    }
-  }
+	// Creating the SDL Texture that is uses to display the color buffer
+	color_buffer_texture = SDL_CreateTexture(
+		renderer,
+		SDL_PIXELFORMAT_ARGB8888,
+		SDL_TEXTUREACCESS_STREAMING,
+		window_width,
+		window_height
+	);
+	int point_count = 0;
+	for (float x = -1; x <= 1; x += 0.25) {
+		for (float y = -1; y <= 1; y += 0.25) {
+			for (float z = -1; z <= 1; z += 0.25) {
+				vec3_t new_point = { .x = x, .y = y, .z = z };
+				cube_points[point_count++] = new_point;
+			}
+		}
+	}
 }
 
 void process_input(void) {
-  SDL_Event event;
-  SDL_PollEvent(&event);
+	SDL_Event event;
+	SDL_PollEvent(&event);
 
-  switch (event.type) {
-    case SDL_QUIT:
-      is_running = false;
-      break;
-    case SDL_KEYDOWN:
-      if (event.key.keysym.sym == SDLK_ESCAPE) {
-        is_running = false;
-      }
-      break;
-  }
+	switch (event.type) {
+		case SDL_QUIT:
+			is_running = false;
+		break;
+		case SDL_KEYDOWN:
+			if (event.key.keysym.sym == SDLK_ESCAPE) {
+				is_running = false;
+			}
+		break;
+	}
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Function that receives a 3d Vector and returns a 2d projected point
 ////////////////////////////////////////////////////////////////////////////////
 vec2_t project(vec3_t point) {
-  vec2_t projected_point = {
-    .x = (fov_factor * point.x),
-    .y = (fov_factor * point.y),
-  };
-  return projected_point;
+	vec2_t projected_point = {
+		.x = (fov_factor * point.x) / point.z,
+		.y = (fov_factor * point.y) / point.z,
+	};
+	return projected_point;
 }
 
 
 void update(void) {
-    for (int i = 0; i < N_POINTS; i++){
-        vec3_t point = cube_points[i];
-        vec2_t projected_point = project(point);
-        
-        projected_points[i] = projected_point;
-    }
+	for (int i = 0; i < N_POINTS; i++){
+		vec3_t point = cube_points[i];
+    point.z -= camera_position.z;
+		vec2_t projected_point = project(point);
+
+		projected_points[i] = projected_point;
+	}
 }
 
 
 void render(void) {
-  draw_grid();
+	draw_grid();
 
-  for (int i = 0; i < N_POINTS; i++){
-    vec2_t projected_point = projected_points[i];
-    draw_rect(
-      projected_point.x + (window_width/2),
-      projected_point.y + (window_height/2),
-      4,
-      4,
-      0xFFFFFF00
-    );
-  }
+	for (int i = 0; i < N_POINTS; i++){
+		vec2_t projected_point = projected_points[i];
+		draw_rect(
+			projected_point.x + (window_width/2),
+			projected_point.y + (window_height/2),
+			4,
+			4,
+			0xFFFFFF00
+		);
+	}
 
-  render_color_buffer();
-  clear_color_buffer(0xFF000000);
+	render_color_buffer();
+	clear_color_buffer(0xFF000000);
 
-  SDL_RenderPresent(renderer);
+	SDL_RenderPresent(renderer);
 }
 
 
 int main(void) {
-  is_running = initialize_window();
-  setup();
+	is_running = initialize_window();
+	setup();
 
-  while (is_running) {
-    process_input();
-    update();
-    render();
-  }
-  destroy_window();
-  return 0;
+	while (is_running) {
+	process_input();
+		update();
+		render();
+	}
+	destroy_window();
+	return 0;
 }