#include <stdint.h>
#include <stdbool.h>
#include <SDL2/SDL.h>
#include "display.h"
#include "vector.h"

////////////////////////////////////////////////////////////
// Declare an array of points
////////////////////////////////////////////////////////////
#define N_POINTS  (9 * 9 * 9)
vec3_t cube_points[N_POINTS];
vec2_t projected_points[N_POINTS];

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);

	// 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);

	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) / 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];
    point.z -= camera_position.z;
		vec2_t projected_point = project(point);

		projected_points[i] = projected_point;
	}
}


void render(void) {
	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
		);
	}

	render_color_buffer();
	clear_color_buffer(0xFF000000);

	SDL_RenderPresent(renderer);
}


int main(void) {
	is_running = initialize_window();
	setup();

	while (is_running) {
	process_input();
		update();
		render();
	}
	destroy_window();
	return 0;
}