// SPDX-License-Identifier: GPL-2.1-or-later
/*
 * Copyright (C) 2009-2010 Jiri "BlueBear" Dluhos
 *                         <jiri.bluebear.dluhos@gmail.com>
 *
 * Copyright (C) 2009-2021 Cyril Hrubis <metan@ucw.cz>
 */

 /*

   This example shows how to mix SDL2 with GFXprim.

  */

#include <stdio.h>
#include <stdlib.h>
#include <SDL2/SDL.h>
#include <gfxprim.h>
#include <backends/gp_sdl_pixmap.h>

#define W 320
#define H 240

static SDL_Surface *surface = NULL;
static SDL_Window *window = NULL;
static gp_pixmap pixmap;

static gp_pixel black_pixel, darkgray_pixel;

void redraw_screen(void)
{
        SDL_LockSurface(surface);

        int w = pixmap.w;
        int h = pixmap.h;

        gp_fill(&pixmap, black_pixel);

        gp_text(&pixmap, NULL, w/2, 20, GP_ALIGN_CENTER | GP_VALIGN_BELOW,
                darkgray_pixel, black_pixel, "GFXprim SDL2 Demo");

        gp_line(&pixmap, 0, 0, w-1, h-1, darkgray_pixel);
        gp_line(&pixmap, 0, h-1, w-1, 0, darkgray_pixel);

        SDL_UnlockSurface(surface);
}

void event_loop(void)
{
        SDL_Event event;

        while (SDL_WaitEvent(&event) > 0) {
                switch (event.type) {
                case SDL_WINDOWEVENT:
                        if (event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED ||
                            event.window.event == SDL_WINDOWEVENT_RESIZED) {
                                SDL_FreeSurface(surface);
                                surface = SDL_GetWindowSurface(window);
                                gp_pixmap_from_sdl_surface(&pixmap, surface);
                        }

                        if (event.window.event == SDL_WINDOWEVENT_EXPOSED ||
                            event.window.event == SDL_WINDOWEVENT_SIZE_CHANGED ||
                            event.window.event == SDL_WINDOWEVENT_RESIZED) {
                                redraw_screen();
                                SDL_UpdateWindowSurface(window);
                        }
                break;
                case SDL_KEYDOWN:
                        switch (event.key.keysym.sym) {
                        case SDLK_ESCAPE:
                                return;
                        default:
                        break;
                        }
                break;
                case SDL_QUIT:
                        return;
                }
        }
}

int main(void)
{
        if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER) != 0) {
                fprintf(stderr, "Could not initialize SDL: %s\n", SDL_GetError());
                return 1;
        }

        window = SDL_CreateWindow("GFXprim SDL2 Demo", SDL_WINDOWPOS_CENTERED,
                                  SDL_WINDOWPOS_CENTERED, W, H, SDL_WINDOW_RESIZABLE);
        if (!window) {
                fprintf(stderr, "Could not open window: %s\n", SDL_GetError());
                SDL_Quit();
                return 1;
        }

        surface = SDL_GetWindowSurface(window);

        gp_pixmap_from_sdl_surface(&pixmap, surface);

        black_pixel = gp_rgb_to_pixmap_pixel(0x00, 0x00, 0x00, &pixmap);
        darkgray_pixel = gp_rgb_to_pixmap_pixel(0x7f, 0x7f, 0x7f, &pixmap);

        redraw_screen();
        SDL_UpdateWindowSurface(window);

        event_loop();

        SDL_FreeSurface(surface);
        SDL_DestroyWindow(window);
        SDL_Quit();
        return 0;
}