//Source: https://bitbucket.org/dandago/gigilabs/src/master/Sdl2PixelDrawing/Sdl2PixelDrawing/main.cpp
#include <unistd.h>
#include <iostream>
#include <SDL2/SDL.h>
//Define window height, width
#define height 1280
#define width   760
int main(){
    bool leftMouseButtonDown = false;
    bool quit = false;
    SDL_Event event;
    SDL_Init(SDL_INIT_VIDEO);
    SDL_Window * window = SDL_CreateWindow("SDL2 Pixel Drawing",  SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, height, width, SDL_WINDOW_FULLSCREEN);
    SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
    //SDL_Renderer * renderer = SDL_CreateRenderer(window, -1, 0);
    SDL_Texture * texture = SDL_CreateTexture(renderer,  SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STATIC, height, width);
    Uint32 * pixels = new Uint32[height * width];
    Uint32 colour =  0xFF0000;
 
    memset(pixels, 255, height * width * sizeof(Uint32)); //int is bg color

    while (!quit){
        SDL_UpdateTexture(texture, NULL, pixels, height * sizeof(Uint32));
        SDL_WaitEvent(&event);

        switch (event.type){
            case SDL_QUIT:
                quit = true;
                break;
            case SDL_MOUSEBUTTONUP:
                if (event.button.button == SDL_BUTTON_LEFT)
                    leftMouseButtonDown = true;
                break;
            case SDL_MOUSEBUTTONDOWN:
                if(event.button.button ==SDL_BUTTON_RIGHT ){
                    memset(pixels, 23, height * width * sizeof(Uint32)); //int is bg color
					}
                 
                if (event.button.button == SDL_BUTTON_LEFT)
                    leftMouseButtonDown = true;
            case SDL_MOUSEMOTION:
                if (leftMouseButtonDown){
                    int mouseX = event.motion.x;
                    int mouseY = event.motion.y;
                    colour+=mouseY*8+mouseX*8;  //makes a nice scaling effect. 
                    if(colour>=0xFFFFFF)
                    colour=0xFF0000;
                    pixels[mouseY * height+ mouseX] = colour;
                    
                     }
                break;
        }
        SDL_RenderClear(renderer);
        SDL_RenderCopy(renderer, texture, NULL, NULL);
        SDL_RenderPresent(renderer);
    }

    delete[] pixels;
    SDL_DestroyTexture(texture);
    SDL_DestroyRenderer(renderer);

    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}