This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
/
testdyngles.c
226 lines (184 loc) · 6.08 KB
1
2
3
4
5
6
7
8
9
10
11
/*
Copyright (C) 1997-2011 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.
*/
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
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
/*
* Small SDL example to demonstrate dynamically loading
* OpenGL lib and functions
*
* (FYI it was supposed to look like snow in the wind or something...)
*
* Compile with :
* gcc testdyngl.c `sdl-config --libs --cflags` -o testdyngl -DHAVE_OPENGL
*
* You can specify a different OpenGL lib on the command line, i.e. :
* ./testdyngl /usr/X11R6/lib/libGL.so.1.2
* or
* ./testdyngl /usr/lib/libGL.so.1.0.4496
*
*/
#include <stdio.h>
#include <stdlib.h>
#include "SDL.h"
#ifdef __IPHONEOS__
#define HAVE_OPENGLES
#endif
#ifdef HAVE_OPENGLES
#include "SDL_opengles.h"
/* Call this instead of exit(), so we can clean up SDL: atexit() is evil. */
static void
quit(int rc)
{
SDL_Quit();
exit(rc);
}
void *
get_funcaddr(const char *p)
{
void *f = SDL_GL_GetProcAddress(p);
if (f) {
return f;
} else {
printf("Unable to get function pointer for %s\n", p);
quit(1);
}
return NULL;
}
typedef struct
{
void (APIENTRY * glEnableClientState) (GLenum array);
65
void (APIENTRY * glDisableClientState) (GLenum array);
66
67
68
69
70
71
72
73
74
75
void (APIENTRY * glVertexPointer) (GLint size, GLenum type,
GLsizei stride,
const GLvoid * pointer);
void (APIENTRY * glDrawArrays) (GLenum mode, GLint first, GLsizei count);
void (APIENTRY * glClearColor) (GLfloat, GLfloat, GLfloat, GLfloat);
void (APIENTRY * glClear) (GLbitfield);
void (APIENTRY * glDisable) (GLenum);
void (APIENTRY * glEnable) (GLenum);
76
void (APIENTRY * glColor4f) (GLfloat, GLfloat, GLfloat, GLfloat);
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
void (APIENTRY * glPointSize) (GLfloat);
void (APIENTRY * glHint) (GLenum, GLenum);
void (APIENTRY * glBlendFunc) (GLenum, GLenum);
void (APIENTRY * glMatrixMode) (GLenum);
void (APIENTRY * glLoadIdentity) ();
void (APIENTRY * glOrthof) (GLfloat, GLfloat, GLfloat, GLfloat,
GLfloat, GLfloat);
void (APIENTRY * glRotatef) (GLfloat, GLfloat, GLfloat, GLfloat);
void (APIENTRY * glViewport) (GLint, GLint, GLsizei, GLsizei);
void (APIENTRY * glFogf) (GLenum, GLfloat);
}
glfuncs;
void
init_glfuncs(glfuncs * f)
{
f->glEnableClientState = get_funcaddr("glEnableClientState");
94
f->glDisableClientState = get_funcaddr("glDisableClientState");
95
96
97
98
99
100
f->glVertexPointer = get_funcaddr("glVertexPointer");
f->glDrawArrays = get_funcaddr("glDrawArrays");
f->glClearColor = get_funcaddr("glClearColor");
f->glClear = get_funcaddr("glClear");
f->glDisable = get_funcaddr("glDisable");
f->glEnable = get_funcaddr("glEnable");
101
f->glColor4f = get_funcaddr("glColor4f");
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
129
130
131
132
133
134
135
136
137
138
139
140
f->glPointSize = get_funcaddr("glPointSize");
f->glHint = get_funcaddr("glHint");
f->glBlendFunc = get_funcaddr("glBlendFunc");
f->glMatrixMode = get_funcaddr("glMatrixMode");
f->glLoadIdentity = get_funcaddr("glLoadIdentity");
f->glOrthof = get_funcaddr("glOrthof");
f->glRotatef = get_funcaddr("glRotatef");
f->glViewport = get_funcaddr("glViewport");
f->glFogf = get_funcaddr("glFogf");
}
#define NB_PIXELS 1000
int
main(int argc, char *argv[])
{
glfuncs f;
int i;
SDL_Event event;
int done = 0;
GLfloat pixels[NB_PIXELS * 3];
const char *gl_library = NULL; /* Use the default GL library */
int video_w, video_h;
/* you may want to change these according to the platform */
video_w = 320;
video_h = 480;
if (argv[1]) {
gl_library = argv[1];
}
if (SDL_Init(SDL_INIT_VIDEO) < 0) {
printf("Unable to init SDL : %s\n", SDL_GetError());
return (1);
}
if (SDL_GL_LoadLibrary(gl_library) < 0) {
141
printf("Unable to dynamically open GL ES lib : %s\n", SDL_GetError());
142
143
144
145
146
147
148
149
150
quit(1);
}
if (SDL_SetVideoMode(video_h, video_w, 0, SDL_OPENGL) == NULL) {
printf("Unable to open video mode : %s\n", SDL_GetError());
quit(1);
}
/* Set the window manager title bar */
151
SDL_WM_SetCaption("SDL Dynamic OpenGL ES Loading Test", "testdyngles");
152
153
154
155
156
157
158
159
160
init_glfuncs(&f);
for (i = 0; i < NB_PIXELS; i++) {
pixels[3 * i] = rand() % 250 - 125;
pixels[3 * i + 1] = rand() % 250 - 125;
pixels[3 * i + 2] = rand() % 250 - 125;
}
161
f.glViewport(0, 0, video_w, video_h);
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
f.glMatrixMode(GL_PROJECTION);
f.glLoadIdentity();
f.glOrthof(-100, 100, -100, 100, -500, 500);
f.glMatrixMode(GL_MODELVIEW);
f.glLoadIdentity();
f.glEnable(GL_DEPTH_TEST);
f.glDisable(GL_TEXTURE_2D);
f.glEnable(GL_BLEND);
f.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
f.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
f.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
f.glEnable(GL_POINT_SMOOTH);
f.glHint(GL_POINT_SMOOTH_HINT, GL_NICEST);
179
f.glPointSize(1.0f);
180
181
182
183
184
f.glEnable(GL_FOG);
f.glFogf(GL_FOG_START, -500);
f.glFogf(GL_FOG_END, 500);
f.glFogf(GL_FOG_DENSITY, 0.005);
185
186
187
f.glVertexPointer(3, GL_FLOAT, 0, pixels);
f.glEnableClientState(GL_VERTEX_ARRAY);
188
189
190
191
192
193
do {
f.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
f.glRotatef(2.0, 1.0, 1.0, 1.0);
f.glRotatef(1.0, 0.0, 1.0, 1.0);
194
f.glColor4f(1.0, 1.0, 1.0, 1.0);
195
196
197
198
199
200
f.glDrawArrays(GL_POINTS, 0, NB_PIXELS);
SDL_GL_SwapBuffers();
while (SDL_PollEvent(&event)) {
201
202
if (event.type == SDL_QUIT)
done = 1;
203
204
205
206
207
208
209
210
if (event.type == SDL_KEYDOWN)
done = 1;
}
SDL_Delay(20);
}
while (!done);
211
212
f.glDisableClientState(GL_VERTEX_ARRAY);
213
214
215
216
217
218
219
220
221
SDL_Quit();
return 0;
}
#else /* HAVE_OPENGLES */
int
main(int argc, char *argv[])
{
222
printf("No OpenGL ES support on this system\n");
223
224
225
226
return 1;
}
#endif /* HAVE_OPENGLES */