#include <stdlib.h>
#include <math.h>
#include <stdio.h>
#include "SDL.h"
#include "SDL_shape.h"

#define SHAPED_WINDOW_X 150
#define SHAPED_WINDOW_Y 150
#define SHAPED_WINDOW_DIMENSION 640

#define TICK_INTERVAL 1000/10

typedef struct LoadedPicture {
	SDL_Surface *surface;
	SDL_Texture *texture;
	SDL_WindowShapeMode mode;
} LoadedPicture;

void render(SDL_Window* window,SDL_Texture *texture,SDL_Rect texture_dimensions) {
	SDL_SelectRenderer(window);
	
	//Clear render-target to blue.
	SDL_SetRenderDrawColor(0x00,0x00,0xff,0xff);
	SDL_RenderClear();
	
	//Render the texture.
	SDL_RenderCopy(texture,&texture_dimensions,&texture_dimensions);
	
	SDL_RenderPresent();
}

static Uint32 next_time;

Uint32 time_left() {
    Uint32 now = SDL_GetTicks();
    if(next_time <= now)
        return 0;
	else
        return next_time - now;
}

int main(int argc,char** argv) {
	Uint8 num_pictures;
	LoadedPicture* pictures;
	int i, j;
	SDL_PixelFormat* format = NULL;
	SDL_Window *window;
	SDL_Color black = {0,0,0,0xff};
	SDL_Event event;
	int event_pending = 0;
	int should_exit = 0;
	unsigned int current_picture;
	int button_down;
	Uint32 pixelFormat = 0;
	int access = 0;
	SDL_Rect texture_dimensions;;

	if(argc < 2) {
    	printf("SDL_Shape requires at least one bitmap file as argument.\n");
    	exit(-1);
    }
	
	if(SDL_VideoInit(NULL) == -1) {
		printf("Could not initialize SDL video.\n");
		exit(-2);
	}
	
	num_pictures = argc - 1;
	pictures = (LoadedPicture *)malloc(sizeof(LoadedPicture)*num_pictures);
	for(i=0;i<num_pictures;i++)
		pictures[i].surface = NULL;
	for(i=0;i<num_pictures;i++) {
		pictures[i].surface = SDL_LoadBMP(argv[i+1]);
		if(pictures[i].surface == NULL) {
			j = 0;
			for(j=0;j<num_pictures;j++)
				if(pictures[j].surface != NULL)
					SDL_FreeSurface(pictures[j].surface);
			free(pictures);
			SDL_VideoQuit();
			printf("Could not load surface from named bitmap file.\n");
			exit(-3);
		}

		format = pictures[i].surface->format;
		if(format->Amask != 0) {
			pictures[i].mode.mode = ShapeModeBinarizeAlpha;
			pictures[i].mode.parameters.binarizationCutoff = 255;
		}
		else {
			pictures[i].mode.mode = ShapeModeColorKey;
			pictures[i].mode.parameters.colorKey = black;
		}
	}
	
	window = SDL_CreateShapedWindow("SDL_Shape test",SHAPED_WINDOW_X,SHAPED_WINDOW_Y,SHAPED_WINDOW_DIMENSION,SHAPED_WINDOW_DIMENSION,SDL_WINDOW_RESIZABLE | SDL_WINDOW_SHOWN);
	if(window == NULL) {
		for(i=0;i<num_pictures;i++)
			SDL_FreeSurface(pictures[i].surface);
		free(pictures);
		SDL_VideoQuit();
		printf("Could not create shaped window for SDL_Shape.\n");
		exit(-4);
	}
	if(SDL_CreateRenderer(window,-1,SDL_RENDERER_PRESENTFLIP2) == -1) {
		SDL_DestroyWindow(window);
		for(i=0;i<num_pictures;i++)
			SDL_FreeSurface(pictures[i].surface);
		free(pictures);
		SDL_VideoQuit();
		printf("Could not create rendering context for SDL_Shape window.\n");
		exit(-5);
	}
	
	for(i=0;i<num_pictures;i++)
		pictures[i].texture = NULL;
	for(i=0;i<num_pictures;i++) {
		pictures[i].texture = SDL_CreateTextureFromSurface(0,pictures[i].surface);
		if(pictures[i].texture == NULL) {
			j = 0;
			for(j=0;j<num_pictures;i++)
				if(pictures[i].texture != NULL)
					SDL_DestroyTexture(pictures[i].texture);
			for(i=0;i<num_pictures;i++)
				SDL_FreeSurface(pictures[i].surface);
			free(pictures);
			SDL_DestroyRenderer(window);
			SDL_DestroyWindow(window);
			SDL_VideoQuit();
			printf("Could not create texture for SDL_shape.\n");
			exit(-6);
		}
	}
	
	event_pending = 0;
	should_exit = 0;
	event_pending = SDL_PollEvent(&event);
	current_picture = 0;
	button_down = 0;
	texture_dimensions.h = 0;
	texture_dimensions.w = 0;
	texture_dimensions.x = 0;
	texture_dimensions.y = 0;
	SDL_QueryTexture(pictures[current_picture].texture,(Uint32 *)&pixelFormat,(int *)&access,&texture_dimensions.w,&texture_dimensions.h);
	SDL_SetWindowSize(window,texture_dimensions.w,texture_dimensions.h);
	SDL_SetWindowShape(window,pictures[current_picture].surface,&pictures[current_picture].mode);
	next_time = SDL_GetTicks() + TICK_INTERVAL;
	while(should_exit == 0) {
		event_pending = SDL_PollEvent(&event);
		if(event_pending == 1) {
			if(event.type == SDL_KEYDOWN) {
				button_down = 1;
				if(event.key.keysym.sym == SDLK_ESCAPE)
					should_exit = 1;
			}
			if(button_down && event.type == SDL_KEYUP) {
				button_down = 0;
				current_picture += 1;
				if(current_picture >= num_pictures)
					current_picture = 0;
				SDL_QueryTexture(pictures[current_picture].texture,(Uint32 *)&pixelFormat,(int *)&access,&texture_dimensions.w,&texture_dimensions.h);
				SDL_SetWindowSize(window,texture_dimensions.w,texture_dimensions.h);
				SDL_SetWindowShape(window,pictures[current_picture].surface,&pictures[current_picture].mode);
			}
			if(event.type == SDL_QUIT)
				should_exit = 1;
			event_pending = 0;
		}
		render(window,pictures[current_picture].texture,texture_dimensions);
		SDL_Delay(time_left());
		next_time += TICK_INTERVAL;
	}
	
	//Free the textures.
	for(i=0;i<num_pictures;i++)
		SDL_DestroyTexture(pictures[i].texture);
	//Destroy the window.
	SDL_DestroyWindow(window);
	//Free the original surfaces backing the textures.
	for(i=0;i<num_pictures;i++)
		SDL_FreeSurface(pictures[i].surface);
	free(pictures);
	//Call SDL_VideoQuit() before quitting.
	SDL_VideoQuit();

	return 0;
}