testspriteminimal.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
/*
Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely.
*/
/* Simple program: Move N sprites around on the screen as fast as possible */
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include "SDL.h"
#define WINDOW_WIDTH 640
#define WINDOW_HEIGHT 480
#define NUM_SPRITES 100
#define MAX_SPEED 1
static SDL_Texture *sprite;
static SDL_Rect positions[NUM_SPRITES];
static SDL_Rect velocities[NUM_SPRITES];
static int sprite_w, sprite_h;
/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void
quit(int rc)
{
exit(rc);
}
int
LoadSprite(char *file, SDL_Renderer *renderer)
{
SDL_Surface *temp;
/* Load the sprite image */
temp = SDL_LoadBMP(file);
if (temp == NULL) {
45
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't load %s: %s\n", file, SDL_GetError());
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
return (-1);
}
sprite_w = temp->w;
sprite_h = temp->h;
/* Set transparent pixel as the pixel at (0,0) */
if (temp->format->palette) {
SDL_SetColorKey(temp, SDL_TRUE, *(Uint8 *) temp->pixels);
} else {
switch (temp->format->BitsPerPixel) {
case 15:
SDL_SetColorKey(temp, SDL_TRUE,
(*(Uint16 *) temp->pixels) & 0x00007FFF);
break;
case 16:
SDL_SetColorKey(temp, SDL_TRUE, *(Uint16 *) temp->pixels);
break;
case 24:
SDL_SetColorKey(temp, SDL_TRUE,
(*(Uint32 *) temp->pixels) & 0x00FFFFFF);
break;
case 32:
SDL_SetColorKey(temp, SDL_TRUE, *(Uint32 *) temp->pixels);
break;
}
}
/* Create textures from the image */
sprite = SDL_CreateTextureFromSurface(renderer, temp);
if (!sprite) {
76
SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "Couldn't create texture: %s\n", SDL_GetError());
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
SDL_FreeSurface(temp);
return (-1);
}
SDL_FreeSurface(temp);
/* We're ready to roll. :) */
return (0);
}
void
MoveSprites(SDL_Renderer * renderer, SDL_Texture * sprite)
{
int i;
int window_w = WINDOW_WIDTH;
int window_h = WINDOW_HEIGHT;
SDL_Rect *position, *velocity;
/* Draw a gray background */
SDL_SetRenderDrawColor(renderer, 0xA0, 0xA0, 0xA0, 0xFF);
SDL_RenderClear(renderer);
/* Move the sprite, bounce at the wall, and draw */
for (i = 0; i < NUM_SPRITES; ++i) {
position = &positions[i];
velocity = &velocities[i];
position->x += velocity->x;
if ((position->x < 0) || (position->x >= (window_w - sprite_w))) {
velocity->x = -velocity->x;
position->x += velocity->x;
}
position->y += velocity->y;
if ((position->y < 0) || (position->y >= (window_h - sprite_h))) {
velocity->y = -velocity->y;
position->y += velocity->y;
}
/* Blit the sprite onto the screen */
SDL_RenderCopy(renderer, sprite, NULL, position);
}
/* Update the screen! */
SDL_RenderPresent(renderer);
}
int
main(int argc, char *argv[])
{
SDL_Window *window;
SDL_Renderer *renderer;
int i, done;
SDL_Event event;
129
130
131
/* Enable standard application logging */
SDL_LogSetPriority(SDL_LOG_CATEGORY_APPLICATION, SDL_LOG_PRIORITY_INFO);
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
if (SDL_CreateWindowAndRenderer(WINDOW_WIDTH, WINDOW_HEIGHT, 0, &window, &renderer) < 0) {
quit(2);
}
if (LoadSprite("icon.bmp", renderer) < 0) {
quit(2);
}
/* Initialize the sprite positions */
srand(time(NULL));
for (i = 0; i < NUM_SPRITES; ++i) {
positions[i].x = rand() % (WINDOW_WIDTH - sprite_w);
positions[i].y = rand() % (WINDOW_HEIGHT - sprite_h);
positions[i].w = sprite_w;
positions[i].h = sprite_h;
velocities[i].x = 0;
velocities[i].y = 0;
while (!velocities[i].x && !velocities[i].y) {
velocities[i].x = (rand() % (MAX_SPEED * 2 + 1)) - MAX_SPEED;
velocities[i].y = (rand() % (MAX_SPEED * 2 + 1)) - MAX_SPEED;
}
}
/* Main render loop */
done = 0;
while (!done) {
/* Check for events */
while (SDL_PollEvent(&event)) {
if (event.type == SDL_QUIT || event.type == SDL_KEYDOWN) {
done = 1;
}
}
MoveSprites(renderer, sprite);
}
quit(0);
return 0; /* to prevent compiler warning */
}
/* vi: set ts=4 sw=4 expandtab: */