Atlas - happy.c
Home / ext / SDL2 / Xcode-iOS / Demos / src
Lines: 1 | Size: 4607 bytes
[Download] [Show on GitHub] [Search similar files] [Raw] [Raw (proxy)] 
[FILE BEGIN]
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 HAPPY_FACE_SIZE 32      /* width and height of happyface */
12
13static SDL_Texture *texture = 0;    /* reference to texture holding happyface */
14
15static struct
16{
17    float x, y;                 /* position of happyface */
18    float xvel, yvel;           /* velocity of happyface */
19} faces[NUM_HAPPY_FACES];
20
21/*
22    Sets initial positions and velocities of happyfaces
23    units of velocity are pixels per millesecond
24*/
25void
26initializeHappyFaces(SDL_Renderer *renderer)
27{
28    int i;
29    int w;
30    int h;
31    SDL_RenderGetLogicalSize(renderer, &w, &h);
32
33    for (i = 0; i < NUM_HAPPY_FACES; i++) {
34        faces[i].x = randomFloat(0.0f, w - HAPPY_FACE_SIZE);
35        faces[i].y = randomFloat(0.0f, h - HAPPY_FACE_SIZE);
36        faces[i].xvel = randomFloat(-60.0f, 60.0f);
37        faces[i].yvel = randomFloat(-60.0f, 60.0f);
38    }
39}
40
41void
42render(SDL_Renderer *renderer, double deltaTime)
43{
44    int i;
45    SDL_Rect srcRect;
46    SDL_Rect dstRect;
47    int w;
48    int h;
49
50    SDL_RenderGetLogicalSize(renderer, &w, &h);
51
52    /* setup boundaries for happyface bouncing */
53    int maxx = w - HAPPY_FACE_SIZE;
54    int maxy = h - HAPPY_FACE_SIZE;
55    int minx = 0;
56    int miny = 0;
57
58    /* setup rects for drawing */
59    srcRect.x = 0;
60    srcRect.y = 0;
61    srcRect.w = HAPPY_FACE_SIZE;
62    srcRect.h = HAPPY_FACE_SIZE;
63    dstRect.w = HAPPY_FACE_SIZE;
64    dstRect.h = HAPPY_FACE_SIZE;
65
66    /* fill background in with black */
67    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
68    SDL_RenderClear(renderer);
69
70    /*
71       loop through all the happy faces:
72       - update position
73       - update velocity (if boundary is hit)
74       - draw
75     */
76    for (i = 0; i < NUM_HAPPY_FACES; i++) {
77        faces[i].x += faces[i].xvel * deltaTime;
78        faces[i].y += faces[i].yvel * deltaTime;
79        if (faces[i].x > maxx) {
80            faces[i].x = maxx;
81            faces[i].xvel = -faces[i].xvel;
82        } else if (faces[i].y > maxy) {
83            faces[i].y = maxy;
84            faces[i].yvel = -faces[i].yvel;
85        }
86        if (faces[i].x < minx) {
87            faces[i].x = minx;
88            faces[i].xvel = -faces[i].xvel;
89        } else if (faces[i].y < miny) {
90            faces[i].y = miny;
91            faces[i].yvel = -faces[i].yvel;
92        }
93        dstRect.x = faces[i].x;
94        dstRect.y = faces[i].y;
95        SDL_RenderCopy(renderer, texture, &srcRect, &dstRect);
96    }
97    /* update screen */
98    SDL_RenderPresent(renderer);
99
100}
101
102/*
103    loads the happyface graphic into a texture
104*/
105void
106initializeTexture(SDL_Renderer *renderer)
107{
108    SDL_Surface *bmp_surface;
109    /* load the bmp */
110    bmp_surface = SDL_LoadBMP("icon.bmp");
111    if (bmp_surface == NULL) {
112        fatalError("could not load bmp");
113    }
114    /* set white to transparent on the happyface */
115    SDL_SetColorKey(bmp_surface, 1,
116                    SDL_MapRGB(bmp_surface->format, 255, 255, 255));
117
118    /* convert RGBA surface to texture */
119    texture = SDL_CreateTextureFromSurface(renderer, bmp_surface);
120    if (texture == 0) {
121        fatalError("could not create texture");
122    }
123    SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
124
125    /* free up allocated memory */
126    SDL_FreeSurface(bmp_surface);
127}
128
129int
130main(int argc, char *argv[])
131{
132    SDL_Window *window;
133    SDL_Renderer *renderer;
134    int done;
135    int width;
136    int height;
137
138    /* initialize SDL */
139    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
140        fatalError("Could not initialize SDL");
141    }
142
143    /* The specified window size doesn't matter - except for its aspect ratio,
144     * which determines whether the window is in portrait or landscape on iOS
145     * (if SDL_WINDOW_RESIZABLE isn't specified). */
146    window = SDL_CreateWindow(NULL, 0, 0, 320, 480, SDL_WINDOW_FULLSCREEN | SDL_WINDOW_ALLOW_HIGHDPI);
147
148    renderer = SDL_CreateRenderer(window, -1, 0);
149
150    SDL_GetWindowSize(window, &width, &height);
151    SDL_RenderSetLogicalSize(renderer, width, height);
152
153    initializeTexture(renderer);
154    initializeHappyFaces(renderer);
155
156
157    /* main loop */
158    done = 0;
159    while (!done) {
160        SDL_Event event;
161        double deltaTime = updateDeltaTime();
162
163        while (SDL_PollEvent(&event)) {
164            if (event.type == SDL_QUIT) {
165                done = 1;
166            }
167        }
168
169        render(renderer, deltaTime);
170        SDL_Delay(1);
171    }
172
173    /* cleanup */
174    SDL_DestroyTexture(texture);
175    /* shutdown SDL */
176    SDL_Quit();
177
178    return 0;
179
180}
181
[FILE END]
(C) 2025 0x4248
(C) 2025 4248 Media and 4248 Systems, All part of 0x4248
See LICENCE files for more information. Not all files are by 0x4248 always check Licencing.