/*
 * Copyright (C) 2025 Matheus Klein Schaefer
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see .
 */

#include "raylib.h"

#if defined(PLATFORM_WEB)
#define CUSTOM_MODAL_DIALOGS          
#include 
#endif

static const char *vs = "#version 100\n"
	"attribute vec3 vertexPosition;\n"
	"attribute vec2 vertexTexCoord;\n"
	"uniform mat4 mvp;\n"
	"uniform vec2 uResolution;\n"
	"varying vec3 FragPos;\n"
	"varying vec2 TexCoord;\n"
	"void main()\n"
	"{\n"
	"	vec4 clip_pos = mvp * vec4(vertexPosition, 1.0);\n"
	"	vec3 ndc = clip_pos.xyz / clip_pos.w;\n"
	"	vec2 screen_pos = (ndc.xy * 0.5 + 0.5) * uResolution;\n"
	"	screen_pos = floor(screen_pos) + 0.5;\n"
	"	vec2 ndc_q = (screen_pos / uResolution) * 2.0 - 1.0;\n"
	"	vec2 clip_xy_q = ndc_q * clip_pos.w;\n"
	"	FragPos  = vertexPosition;\n"
	"	TexCoord = vertexTexCoord;\n"
	"	gl_Position = vec4(clip_xy_q, clip_pos.z, clip_pos.w);\n"
	"}\n"
	"\0";

static const char *fs = "#version 100\n"
	"precision mediump float;\n"
	"varying vec3 FragPos;\n"
	"varying vec2 TexCoord;\n"
	"uniform sampler2D diffuse;\n"
	"uniform vec4 colDiffuse;\n"
	"void main()\n"
	"{\n"
	"	vec4 texel = texture2D(diffuse, TexCoord);\n"
	"	gl_FragColor = texel * colDiffuse;\n"
	"}\n"
	"\0";

void UpdateDrawFrame(void);

Model model;

Camera camera = { 0 };

int main(void)
{
	const int screenWidth = 640;
	const int screenHeight = 480;

	InitWindow(screenWidth, screenHeight, "Shader demo");

	camera.position = (Vector3){ 5.0f, 5.0f, 5.0f };
	camera.target = (Vector3){ 0.0f, 0.0f, 0.0f };
	camera.up = (Vector3){ 0.0f, 1.0f, 0.0f };
	camera.fovy = 45.0f;
	camera.projection = CAMERA_PERSPECTIVE;

	Shader shader = LoadShaderFromMemory(vs, fs);
	int resloc = GetShaderLocation(shader, "uResolution");
	float res[2] = {screenWidth, screenHeight};
	SetShaderValue(shader, resloc, res, SHADER_UNIFORM_VEC2);
	
	model = LoadModel("assets/cube.m3d");
	Texture texture = LoadTexture("assets/tile.qoi");
	for(int i = 0; i < model.materialCount; i++)
	{
		model.materials[i].shader = shader;
		model.materials[i].maps[MATERIAL_MAP_DIFFUSE].texture = texture;
	}

	emscripten_set_main_loop(UpdateDrawFrame, 60, 1);

	CloseWindow();

	return 0;
}

void UpdateDrawFrame(void)
{
	UpdateCamera(&camera, CAMERA_ORBITAL);
	BeginDrawing();
		ClearBackground(BLACK);
		BeginMode3D(camera);
			DrawModel(model, (Vector3){ 0 }, 1.0f, WHITE);
		EndMode3D();
		DrawFPS(10, 10);
	EndDrawing();
}