#include <SDL.h>
#include <SDL_image.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <errno.h>
#include <string.h>
#include <assert.h>
#include "kiss.h"

char *title = "SDL 14 - Animated Sprites";
SDL_Window *window;
SDL_Renderer *renderer;
SDL_Texture *sprite_sheet;
SDL_Rect sprite[] = {
   { 0, 0, 100, 200 },
   { 100, 0, 100, 200 },
   { 200, 0, 100, 200 },
   { 300, 0, 100, 200 },
};

int
init_sdl(void)
{
   int status = -1;
   int x = SDL_WINDOWPOS_UNDEFINED;
   int y = SDL_WINDOWPOS_UNDEFINED;
   int width = 800;
   int height = 600;
   int flags = 0;       // SDL_WINDOW_FULLSCREEN_DESKTOP

   SDL_INIT(SDL_INIT_VIDEO);
   IMG_INIT(IMG_INIT_PNG);
   window = SDL_CREATEWINDOW(title, x, y, width, height, flags);
   renderer = SDL_CREATERENDERER(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
   status = 0;
error:
   return status;
}

#define INIT_SDL(...) SDL_ZERO(init_sdl, __VA_ARGS__)

SDL_Texture *
load_texture(char *path)
{
   SDL_Texture *ret = NULL;
   SDL_Texture *texture = NULL;
   SDL_Surface *surface = NULL;
   surface = IMG_LOAD(path);
//	SDL_SETCOLORKEY(surface, SDL_TRUE, SDL_MapRGB(surface->format, 0x00, 0xFF, 0xFF));
   texture = SDL_CREATETEXTUREFROMSURFACE(renderer, surface);
   SDL_SETTEXTUREBLENDMODE(texture, SDL_BLENDMODE_BLEND);
   ret = texture;
error:
   if (!ret)
     SDL_DestroyTexture(texture);
   SDL_FreeSurface(surface);
   return ret;
}

#define LOAD_TEXTURE(...) SDL_CHK(load_texture, __VA_ARGS__)

int
sprite_draw_ex(SDL_Rect *sprite, int x, int y, double zoom, double angle, SDL_RendererFlip flip, const SDL_Color *c)
{
   int status = -1;
   SDL_Rect target = { x, y, sprite->w * zoom, sprite->h * zoom };
   if (c)
     {
        SDL_SETTEXTURECOLORMOD(sprite_sheet, c->r, c->g, c->b);
        SDL_SETTEXTUREALPHAMOD(sprite_sheet, c->a);
     }
   SDL_RENDERCOPYEX(renderer, sprite_sheet, sprite, &target, angle, NULL, flip);
   if (c)
     {
        SDL_SETTEXTURECOLORMOD(sprite_sheet, 0xFF, 0xFF, 0xFF);
        SDL_SETTEXTUREALPHAMOD(sprite_sheet, 0xFF);
     }
   status = 0;
error:
   return status;
}

#define SPRITE_DRAW_EX(...) SDL_ZERO(sprite_draw_ex, __VA_ARGS__)

void
close_sdl(void)
{
   SDL_DestroyRenderer(renderer);
   SDL_DestroyWindow(window);
   IMG_Quit();
   SDL_Quit();
}

double x = 0;
double y = 0;
double dx = 0;
double dy = 0;
double angle = 0;
SDL_Color tint = { 0xFF, 0xFF, 0xFF, 0xFF };
int flip = 0;

int frame = 0;

int
draw(void)
{
   int status = -1;
   int w, h;
   double zoom = 1;
   SDL_GetWindowSize(window, &w, &h);
   SDL_RendererFlip sdl_flip = 0;

   SDL_SetRenderDrawColor(renderer, 0x7F, 0x7F, 0x7F, 0xFF);
   SDL_RENDERCLEAR(renderer);
   if (dx < 0)
     flip = 1;
   if (dx > 0)
     flip = 0;
   if (flip)
     sdl_flip = SDL_FLIP_HORIZONTAL;
   SPRITE_DRAW_EX(&sprite[(frame / 16) % NELEMS(sprite)], (int)x, (int)y, zoom, angle, sdl_flip, &tint);
   SDL_RenderPresent(renderer);
   if (dx > 4) dx = 4;
   if (dx < -4) dx = -4;
   if (dy > 4) dy = 4;
   if (dy < -4) dy = -4;
   if (dx || dy)
     frame += (int)hypot(dx, dy);
   x += dx * cos(RAD(angle)) - dy *sin(RAD(angle));
   y += dx * sin(RAD(angle)) + dy *cos(RAD(angle));
   status = 0;
error:
   return status;
}

#define DRAW(...) SDL_ZERO(draw, __VA_ARGS__)

void
key_down(SDL_Keycode k)
{
   switch (k)
     {
      case SDLK_LEFT: dx -= 2; break;

      case SDLK_RIGHT: dx += 2; break;

      case SDLK_UP: dy -= 2; break;

      case SDLK_DOWN: dy += 2; break;

      case SDLK_q: tint.r += 4; break;

      case SDLK_w: tint.g += 4; break;

      case SDLK_e: tint.b += 4; break;

      case SDLK_r: tint.a += 4; break;

      case SDLK_a: tint.r -= 4; break;

      case SDLK_s: tint.g -= 4; break;

      case SDLK_d: tint.b -= 4; break;

      case SDLK_f: tint.a -= 4; break;

      case SDLK_t: angle += 15; break;

      case SDLK_g: angle -= 15; break;

      default: dx = 0; dy = 0; break;
     }
}

int
main(void)
{
   int exit_status = EXIT_FAILURE;
   bool quit = 0;
   SDL_Event e;

   INIT_SDL();

   sprite_sheet = LOAD_TEXTURE("animation.png");

   while (!quit)
     {
        DRAW();
        if (SDL_PollEvent(&e))
          {
             if (e.type == SDL_QUIT)
               quit = 1;
             else if (e.type == SDL_KEYDOWN)
               key_down(e.key.keysym.sym);
          }
     }

   exit_status = EXIT_SUCCESS;
error:
   SDL_DestroyTexture(sprite_sheet);
   close_sdl();
   exit(exit_status);
}