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comparison XCodeiPhoneOS/Demos/src/happy.c @ 2765:f55c87ae336b

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Final merge of Google Summer of Code 2008 work... Bring SDL to iPhone and iPod Touch by Holmes Futrell, mentored by Sam Lantinga
author Sam Lantinga <slouken@libsdl.org>
date Sat, 04 Oct 2008 06:46:59 +0000
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children 9dde605c7540
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2764:4868c0df2e83 2765:f55c87ae336b
1 /*
2 * happy.c
3 * written by Holmes Futrell
4 * use however you want
5 */
6
7 #include "SDL.h"
8 #include "common.h"
9
10 #define NUM_HAPPY_FACES 100 /* number of faces to draw */
11 #define MILLESECONDS_PER_FRAME 16 /* about 60 frames per second */
12 #define HAPPY_FACE_SIZE 32 /* width and height of happyface (pixels) */
13
14 static SDL_TextureID texture_id = 0; /* reference to texture holding happyface */
15
16 static struct
17 {
18 float x, y; /* position of happyface */
19 float xvel, yvel; /* velocity of happyface */
20 } faces[NUM_HAPPY_FACES];
21
22 /*
23 Sets initial positions and velocities of happyfaces
24 units of velocity are pixels per millesecond
25 */
26 void
27 initializeHappyFaces()
28 {
29 int i;
30 for (i = 0; i < NUM_HAPPY_FACES; i++) {
31 faces[i].x = randomFloat(0.0f, SCREEN_WIDTH - HAPPY_FACE_SIZE);
32 faces[i].y = randomFloat(0.0f, SCREEN_HEIGHT - HAPPY_FACE_SIZE);
33 faces[i].xvel = randomFloat(-0.1f, 0.1f);
34 faces[i].yvel = randomFloat(-0.1f, 0.1f);
35 }
36 }
37
38 void
39 render(void)
40 {
41
42 int i;
43 SDL_Rect srcRect;
44 SDL_Rect dstRect;
45
46 /* setup boundaries for happyface bouncing */
47 Uint16 maxx = SCREEN_WIDTH - HAPPY_FACE_SIZE;
48 Uint16 maxy = SCREEN_HEIGHT - HAPPY_FACE_SIZE;
49 Uint16 minx = 0;
50 Uint16 miny = 0;
51
52 /* setup rects for drawing */
53 srcRect.x = 0;
54 srcRect.y = 0;
55 srcRect.w = HAPPY_FACE_SIZE;
56 srcRect.h = HAPPY_FACE_SIZE;
57 dstRect.w = HAPPY_FACE_SIZE;
58 dstRect.h = HAPPY_FACE_SIZE;
59
60 /* fill background in with black */
61 SDL_RenderFill(0, 0, 0, 255, NULL);
62
63 /*
64 loop through all the happy faces:
65 - update position
66 - update velocity (if boundary is hit)
67 - draw
68 */
69 for (i = 0; i < NUM_HAPPY_FACES; i++) {
70 faces[i].x += faces[i].xvel * MILLESECONDS_PER_FRAME;
71 faces[i].y += faces[i].yvel * MILLESECONDS_PER_FRAME;
72 if (faces[i].x > maxx) {
73 faces[i].x = maxx;
74 faces[i].xvel = -faces[i].xvel;
75 } else if (faces[i].y > maxy) {
76 faces[i].y = maxy;
77 faces[i].yvel = -faces[i].yvel;
78 }
79 if (faces[i].x < minx) {
80 faces[i].x = minx;
81 faces[i].xvel = -faces[i].xvel;
82 } else if (faces[i].y < miny) {
83 faces[i].y = miny;
84 faces[i].yvel = -faces[i].yvel;
85 }
86 dstRect.x = faces[i].x;
87 dstRect.y = faces[i].y;
88 SDL_RenderCopy(texture_id, &srcRect, &dstRect);
89 }
90 /* update screen */
91 SDL_RenderPresent();
92
93 }
94
95 /*
96 loads the happyface graphic into a texture
97 */
98 void
99 initializeTexture()
100 {
101 SDL_Surface *bmp_surface;
102 SDL_Surface *bmp_surface_rgba;
103 int format = SDL_PIXELFORMAT_ABGR8888; /* desired texture format */
104 Uint32 Rmask, Gmask, Bmask, Amask; /* masks for desired format */
105 int bpp; /* bits per pixel for desired format */
106 /* load the bmp */
107 bmp_surface = SDL_LoadBMP("icon.bmp");
108 if (bmp_surface == NULL) {
109 fatalError("could not load bmp");
110 }
111 /* set white to transparent on the happyface */
112 SDL_SetColorKey(bmp_surface, 1,
113 SDL_MapRGB(bmp_surface->format, 255, 255, 255));
114 SDL_PixelFormatEnumToMasks(format, &bpp, &Rmask, &Gmask, &Bmask, &Amask);
115 /*
116 create a new RGBA surface and blit the bmp to it
117 this is an extra step, but it seems to be necessary
118 is this a bug?
119 */
120 bmp_surface_rgba =
121 SDL_CreateRGBSurface(0, bmp_surface->w, bmp_surface->h, bpp, Rmask,
122 Gmask, Bmask, Amask);
123 SDL_BlitSurface(bmp_surface, NULL, bmp_surface_rgba, NULL);
124
125 /* convert RGBA surface to texture */
126 texture_id = SDL_CreateTextureFromSurface(format, bmp_surface_rgba);
127 if (texture_id == 0) {
128 fatalError("could not create texture");
129 }
130 SDL_SetTextureBlendMode(texture_id, SDL_TEXTUREBLENDMODE_BLEND);
131
132 /* free up allocated memory */
133 SDL_FreeSurface(bmp_surface_rgba);
134 SDL_FreeSurface(bmp_surface);
135 }
136
137 int
138 main(int argc, char *argv[])
139 {
140
141 SDL_WindowID windowID;
142 Uint32 startFrame;
143 Uint32 endFrame;
144 Uint32 delay;
145 int done;
146
147 /* initialize SDL */
148 if (SDL_Init(SDL_INIT_VIDEO) < 0) {
149 fatalError("Could not initialize SDL");
150 }
151 windowID = SDL_CreateWindow(NULL, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT,
152 SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN |
153 SDL_WINDOW_BORDERLESS);
154
155 SDL_CreateRenderer(windowID, -1, 0);
156
157 initializeTexture();
158 initializeHappyFaces();
159
160 /* main loop */
161 done = 0;
162 while (!done) {
163 startFrame = SDL_GetTicks();
164 SDL_Event event;
165 while (SDL_PollEvent(&event)) {
166 if (event.type == SDL_QUIT) {
167 done = 1;
168 }
169 }
170 render();
171 endFrame = SDL_GetTicks();
172
173 /* figure out how much time we have left, and then sleep */
174 delay = MILLESECONDS_PER_FRAME - (endFrame - startFrame);
175 if (delay < 0) {
176 delay = 0;
177 } else if (delay > MILLESECONDS_PER_FRAME) {
178 delay = MILLESECONDS_PER_FRAME;
179 }
180 SDL_Delay(delay);
181 }
182
183 /* cleanup */
184 SDL_DestroyTexture(texture_id);
185 /* shutdown SDL */
186 SDL_Quit();
187
188 return 0;
189
190 }