SDL  2.0
testdrawchessboard.c
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1 /*
2  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
3 
4  This software is provided 'as-is', without any express or implied
5  warranty. In no event will the authors be held liable for any damages
6  arising from the use of this software.
7 
8  Permission is granted to anyone to use this software for any purpose,
9  including commercial applications, and to alter it and redistribute it
10  freely.
11 
12  This file is created by : Nitin Jain (nitin.j4@samsung.com)
13 */
14 
15 /* Sample program: Draw a Chess Board by using SDL_CreateSoftwareRenderer API */
16 
17 #include <stdlib.h>
18 #include <stdio.h>
19 
20 #ifdef __EMSCRIPTEN__
21 #include <emscripten/emscripten.h>
22 #endif
23 
24 #include "SDL.h"
25 
26 SDL_Window *window;
27 SDL_Renderer *renderer;
28 SDL_Surface *surface;
29 int done;
30 
31 void
32 DrawChessBoard(SDL_Renderer * renderer)
33 {
34  int row = 0,column = 0,x = 0;
35  SDL_Rect rect, darea;
36 
37  /* Get the Size of drawing surface */
38  SDL_RenderGetViewport(renderer, &darea);
39 
40  for( ; row < 8; row++)
41  {
42  column = row%2;
43  x = column;
44  for( ; column < 4+(row%2); column++)
45  {
46  SDL_SetRenderDrawColor(renderer, 0, 0, 0, 0xFF);
47 
48  rect.w = darea.w/8;
49  rect.h = darea.h/8;
50  rect.x = x * rect.w;
51  rect.y = row * rect.h;
52  x = x + 2;
53  SDL_RenderFillRect(renderer, &rect);
54  }
55  }
56 }
57 
58 void
59 loop()
60 {
61  SDL_Event e;
62  while (SDL_PollEvent(&e)) {
63 
64  /* Re-create when window has been resized */
65  if ((e.type == SDL_WINDOWEVENT) && (e.window.event == SDL_WINDOWEVENT_SIZE_CHANGED)) {
66 
67  SDL_DestroyRenderer(renderer);
68 
69  surface = SDL_GetWindowSurface(window);
70  renderer = SDL_CreateSoftwareRenderer(surface);
71  /* Clear the rendering surface with the specified color */
72  SDL_SetRenderDrawColor(renderer, 0xFF, 0xFF, 0xFF, 0xFF);
73  SDL_RenderClear(renderer);
74  }
75 
76  if (e.type == SDL_QUIT) {
77  done = 1;
78 #ifdef __EMSCRIPTEN__
79  emscripten_cancel_main_loop();
80 #endif
81  return;
82  }
83 
84  if ((e.type == SDL_KEYDOWN) && (e.key.keysym.sym == SDLK_ESCAPE)) {
85  done = 1;
86 #ifdef __EMSCRIPTEN__
87  emscripten_cancel_main_loop();
88 #endif
89  return;
90  }
91  }
92 
93  DrawChessBoard(renderer);
94 
95  /* Got everything on rendering surface,
96  now Update the drawing image on window screen */
97  SDL_UpdateWindowSurface(window);
98 }
99 
100 int
101 main(int argc, char *argv[])
102 {
103  /* Enable standard application logging */
104  SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
105 
106  /* Initialize SDL */
107  if(SDL_Init(SDL_INIT_VIDEO) != 0)
108  {
109  SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "SDL_Init fail : %s\n", SDL_GetError());
110  return 1;
111  }
112 
113 
114  /* Create window and renderer for given surface */
115  window = SDL_CreateWindow("Chess Board", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_RESIZABLE);
116  if(!window)
117  {
118  SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Window creation fail : %s\n",SDL_GetError());
119  return 1;
120  }
121  surface = SDL_GetWindowSurface(window);
122  renderer = SDL_CreateSoftwareRenderer(surface);
123  if(!renderer)
124  {
125  SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Render creation for surface fail : %s\n",SDL_GetError());
126  return 1;
127  }
128 
129  /* Clear the rendering surface with the specified color */
130  SDL_SetRenderDrawColor(renderer, 0xFF, 0xFF, 0xFF, 0xFF);
131  SDL_RenderClear(renderer);
132 
133 
134  /* Draw the Image on rendering surface */
135  done = 0;
136 #ifdef __EMSCRIPTEN__
137  emscripten_set_main_loop(loop, 0, 1);
138 #else
139  while (!done) {
140  loop();
141  }
142 #endif
143 
144  SDL_Quit();
145  return 0;
146 }
147