#ifndef GLAD
#define GLAD
#include <glad/glad.h>
#endif 

#include <GLFW/glfw3.h>
#include <cmath>
#include <stdio.h>
#include <string.h>
#include <iostream>
#include <ostream>
#include <png.h>

#include "block.hpp"
#include "chunk.hpp"

unsigned char* loadImage(const char* fileName, int* width, int* height, int* numberOfChannels){
	png_image image;
	//Standard practice when working with libpng
	image.version= PNG_IMAGE_VERSION;
	image.opaque=NULL;

	png_image_begin_read_from_file(&image,fileName);

	//Error handling
	switch(image.warning_or_error){
		case 0:
			break;
		case 1:
			printf("Warning while reading %s: %s\n",fileName,image.message);
			break;
		case 2:
		case 3:
			printf("Error while reading %s: %s\n",fileName, image.message);
			return(NULL);
	}

#define FORMAT PNG_FORMAT_RGBA
	image.format = FORMAT;


	//The amount of memory one row of the image takes up
	size_t row_stride = PNG_IMAGE_SAMPLE_CHANNELS(FORMAT)*image.width;


	//create the buffer
	unsigned char* buffer = (unsigned char*)malloc(row_stride*image.height);

	//Reads the image and stores it in buffer
   	png_image_finish_read(&image, NULL, buffer, row_stride, NULL);


	*width = image.width;
	*height = image.height;
	*numberOfChannels = PNG_IMAGE_SAMPLE_CHANNELS(FORMAT);
	
	png_image_free(&image);

	return(buffer);
}
unsigned int createTexture(const char* pngFile){
	int width,height,nrChannels;
	unsigned char* data = loadImage(pngFile, &width,&height,&nrChannels);

	unsigned int texture;
	glGenTextures(1,&texture);
	glBindTexture(GL_TEXTURE_2D,texture);

	//This makes sure the texture is pixelated and not blurry
   	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
   	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

	//Sends the bitmap to the GPU
	glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,width,height,0,GL_RGBA,GL_UNSIGNED_BYTE,data);
	free(data);
	return(texture);
}