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
45
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
76
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
129
130
131
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
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
|
/**************************************************************************
*
* Copyright 2008 VMware, Inc.
* All Rights Reserved.
*
**************************************************************************/
/*
* Draw a triangle with X/EGL and OpenGL ES 2.x
*/
#define USE_FULL_GL 0
#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/keysym.h>
#if USE_FULL_GL
#include "gl_wrap.h" /* use full OpenGL */
#else
#include <GLES2/gl2.h> /* use OpenGL ES 2.x */
#endif
#include <EGL/egl.h>
#define FLOAT_TO_FIXED(X) ((X) * 65535.0)
static GLfloat view_rotx = 0.0, view_roty = 0.0;
static GLint u_matrix = -1;
static GLint attr_pos = 0, attr_color = 1;
static void
make_z_rot_matrix(GLfloat angle, GLfloat *m)
{
float c = cos(angle * M_PI / 180.0);
float s = sin(angle * M_PI / 180.0);
int i;
for (i = 0; i < 16; i++)
m[i] = 0.0;
m[0] = m[5] = m[10] = m[15] = 1.0;
m[0] = c;
m[1] = s;
m[4] = -s;
m[5] = c;
}
static void
make_scale_matrix(GLfloat xs, GLfloat ys, GLfloat zs, GLfloat *m)
{
int i;
for (i = 0; i < 16; i++)
m[i] = 0.0;
m[0] = xs;
m[5] = ys;
m[10] = zs;
m[15] = 1.0;
}
static void
mul_matrix(GLfloat *prod, const GLfloat *a, const GLfloat *b)
{
#define A(row,col) a[(col<<2)+row]
#define B(row,col) b[(col<<2)+row]
#define P(row,col) p[(col<<2)+row]
GLfloat p[16];
GLint i;
for (i = 0; i < 4; i++) {
const GLfloat ai0=A(i,0), ai1=A(i,1), ai2=A(i,2), ai3=A(i,3);
P(i,0) = ai0 * B(0,0) + ai1 * B(1,0) + ai2 * B(2,0) + ai3 * B(3,0);
P(i,1) = ai0 * B(0,1) + ai1 * B(1,1) + ai2 * B(2,1) + ai3 * B(3,1);
P(i,2) = ai0 * B(0,2) + ai1 * B(1,2) + ai2 * B(2,2) + ai3 * B(3,2);
P(i,3) = ai0 * B(0,3) + ai1 * B(1,3) + ai2 * B(2,3) + ai3 * B(3,3);
}
memcpy(prod, p, sizeof(p));
#undef A
#undef B
#undef PROD
}
static void
draw(void)
{
static const GLfloat verts[3][2] = {
{ -1, -1 },
{ 1, -1 },
{ 0, 1 }
};
static const GLfloat colors[3][3] = {
{ 1, 0, 0 },
{ 0, 1, 0 },
{ 0, 0, 1 }
};
GLfloat mat[16], rot[16], scale[16];
/* Set modelview/projection matrix */
make_z_rot_matrix(view_rotx, rot);
make_scale_matrix(0.5, 0.5, 0.5, scale);
mul_matrix(mat, rot, scale);
glUniformMatrix4fv(u_matrix, 1, GL_FALSE, mat);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
{
glVertexAttribPointer(attr_pos, 2, GL_FLOAT, GL_FALSE, 0, verts);
glVertexAttribPointer(attr_color, 3, GL_FLOAT, GL_FALSE, 0, colors);
glEnableVertexAttribArray(attr_pos);
glEnableVertexAttribArray(attr_color);
glDrawArrays(GL_TRIANGLES, 0, 3);
glDisableVertexAttribArray(attr_pos);
glDisableVertexAttribArray(attr_color);
}
}
/* new window size or exposure */
static void
reshape(int width, int height)
{
glViewport(0, 0, (GLint) width, (GLint) height);
}
static void
create_shaders(void)
{
static const char *fragShaderText =
"precision mediump float;\n"
"varying vec4 v_color;\n"
"void main() {\n"
" gl_FragColor = v_color;\n"
"}\n";
static const char *vertShaderText =
"uniform mat4 modelviewProjection;\n"
"attribute vec4 pos;\n"
"attribute vec4 color;\n"
"varying vec4 v_color;\n"
"void main() {\n"
" gl_Position = modelviewProjection * pos;\n"
" v_color = color;\n"
"}\n";
GLuint fragShader, vertShader, program;
GLint stat;
fragShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragShader, 1, (const char **) &fragShaderText, NULL);
glCompileShader(fragShader);
glGetShaderiv(fragShader, GL_COMPILE_STATUS, &stat);
if (!stat) {
printf("Error: fragment shader did not compile!\n");
exit(1);
}
vertShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertShader, 1, (const char **) &vertShaderText, NULL);
glCompileShader(vertShader);
glGetShaderiv(vertShader, GL_COMPILE_STATUS, &stat);
if (!stat) {
printf("Error: vertex shader did not compile!\n");
exit(1);
}
program = glCreateProgram();
glAttachShader(program, fragShader);
glAttachShader(program, vertShader);
glLinkProgram(program);
glGetProgramiv(program, GL_LINK_STATUS, &stat);
if (!stat) {
char log[1000];
GLsizei len;
glGetProgramInfoLog(program, 1000, &len, log);
printf("Error: linking:\n%s\n", log);
exit(1);
}
glUseProgram(program);
if (1) {
/* test setting attrib locations */
glBindAttribLocation(program, attr_pos, "pos");
glBindAttribLocation(program, attr_color, "color");
glLinkProgram(program); /* needed to put attribs into effect */
}
else {
/* test automatic attrib locations */
attr_pos = glGetAttribLocation(program, "pos");
attr_color = glGetAttribLocation(program, "color");
}
u_matrix = glGetUniformLocation(program, "modelviewProjection");
printf("Uniform modelviewProjection at %d\n", u_matrix);
printf("Attrib pos at %d\n", attr_pos);
printf("Attrib color at %d\n", attr_color);
}
static void
init(void)
{
typedef void (*proc)();
#if 1 /* test code */
proc p = eglGetProcAddress("glMapBufferOES");
assert(p);
#endif
glClearColor(0.4, 0.4, 0.4, 0.0);
create_shaders();
}
/*
* Create an RGB, double-buffered X window.
* Return the window and context handles.
*/
static void
make_x_window(Display *x_dpy, EGLDisplay egl_dpy,
const char *name,
int x, int y, int width, int height,
Window *winRet,
EGLContext *ctxRet,
EGLSurface *surfRet)
{
static const EGLint attribs[] = {
EGL_RED_SIZE, 1,
EGL_GREEN_SIZE, 1,
EGL_BLUE_SIZE, 1,
EGL_DEPTH_SIZE, 1,
EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
EGL_NONE
};
#if USE_FULL_GL
static const EGLint ctx_attribs[] = {
EGL_NONE
};
#else
static const EGLint ctx_attribs[] = {
EGL_CONTEXT_CLIENT_VERSION, 2,
EGL_NONE
};
#endif
int scrnum;
XSetWindowAttributes attr;
unsigned long mask;
Window root;
Window win;
XVisualInfo *visInfo, visTemplate;
int num_visuals;
EGLContext ctx;
EGLConfig config;
EGLint num_configs;
EGLint vid;
scrnum = DefaultScreen( x_dpy );
root = RootWindow( x_dpy, scrnum );
if (!eglChooseConfig( egl_dpy, attribs, &config, 1, &num_configs)) {
printf("Error: couldn't get an EGL visual config\n");
exit(1);
}
assert(config);
assert(num_configs > 0);
if (!eglGetConfigAttrib(egl_dpy, config, EGL_NATIVE_VISUAL_ID, &vid)) {
printf("Error: eglGetConfigAttrib() failed\n");
exit(1);
}
/* The X window visual must match the EGL config */
visTemplate.visualid = vid;
visInfo = XGetVisualInfo(x_dpy, VisualIDMask, &visTemplate, &num_visuals);
if (!visInfo) {
printf("Error: couldn't get X visual\n");
exit(1);
}
/* window attributes */
attr.background_pixel = 0;
attr.border_pixel = 0;
attr.colormap = XCreateColormap( x_dpy, root, visInfo->visual, AllocNone);
attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
win = XCreateWindow( x_dpy, root, 0, 0, width, height,
0, visInfo->depth, InputOutput,
visInfo->visual, mask, &attr );
/* set hints and properties */
{
XSizeHints sizehints;
sizehints.x = x;
sizehints.y = y;
sizehints.width = width;
sizehints.height = height;
sizehints.flags = USSize | USPosition;
XSetNormalHints(x_dpy, win, &sizehints);
XSetStandardProperties(x_dpy, win, name, name,
None, (char **)NULL, 0, &sizehints);
}
#if USE_FULL_GL /* XXX fix this when eglBindAPI() works */
eglBindAPI(EGL_OPENGL_API);
#else
eglBindAPI(EGL_OPENGL_ES_API);
#endif
ctx = eglCreateContext(egl_dpy, config, EGL_NO_CONTEXT, ctx_attribs );
if (!ctx) {
printf("Error: eglCreateContext failed\n");
exit(1);
}
#if !USE_FULL_GL
/* test eglQueryContext() */
{
EGLint val;
eglQueryContext(egl_dpy, ctx, EGL_CONTEXT_CLIENT_VERSION, &val);
assert(val == 2);
}
#endif
*surfRet = eglCreateWindowSurface(egl_dpy, config, win, NULL);
if (!*surfRet) {
printf("Error: eglCreateWindowSurface failed\n");
exit(1);
}
/* sanity checks */
{
EGLint val;
eglQuerySurface(egl_dpy, *surfRet, EGL_WIDTH, &val);
assert(val == width);
eglQuerySurface(egl_dpy, *surfRet, EGL_HEIGHT, &val);
assert(val == height);
assert(eglGetConfigAttrib(egl_dpy, config, EGL_SURFACE_TYPE, &val));
assert(val & EGL_WINDOW_BIT);
}
XFree(visInfo);
*winRet = win;
*ctxRet = ctx;
}
static void
event_loop(Display *dpy, Window win,
EGLDisplay egl_dpy, EGLSurface egl_surf)
{
while (1) {
int redraw = 0;
XEvent event;
XNextEvent(dpy, &event);
switch (event.type) {
case Expose:
redraw = 1;
break;
case ConfigureNotify:
reshape(event.xconfigure.width, event.xconfigure.height);
break;
case KeyPress:
{
char buffer[10];
int r, code;
code = XLookupKeysym(&event.xkey, 0);
if (code == XK_Left) {
view_roty += 5.0;
}
else if (code == XK_Right) {
view_roty -= 5.0;
}
else if (code == XK_Up) {
view_rotx += 5.0;
}
else if (code == XK_Down) {
view_rotx -= 5.0;
}
else {
r = XLookupString(&event.xkey, buffer, sizeof(buffer),
NULL, NULL);
if (buffer[0] == 27) {
/* escape */
return;
}
}
}
redraw = 1;
break;
default:
; /*no-op*/
}
if (redraw) {
draw();
eglSwapBuffers(egl_dpy, egl_surf);
}
}
}
static void
usage(void)
{
printf("Usage:\n");
printf(" -display <displayname> set the display to run on\n");
printf(" -info display OpenGL renderer info\n");
}
int
main(int argc, char *argv[])
{
const int winWidth = 300, winHeight = 300;
Display *x_dpy;
Window win;
EGLSurface egl_surf;
EGLContext egl_ctx;
EGLDisplay egl_dpy;
char *dpyName = NULL;
GLboolean printInfo = GL_FALSE;
EGLint egl_major, egl_minor;
int i;
const char *s;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-display") == 0) {
dpyName = argv[i+1];
i++;
}
else if (strcmp(argv[i], "-info") == 0) {
printInfo = GL_TRUE;
}
else {
usage();
return -1;
}
}
x_dpy = XOpenDisplay(dpyName);
if (!x_dpy) {
printf("Error: couldn't open display %s\n",
dpyName ? dpyName : getenv("DISPLAY"));
return -1;
}
egl_dpy = eglGetDisplay(x_dpy);
if (!egl_dpy) {
printf("Error: eglGetDisplay() failed\n");
return -1;
}
if (!eglInitialize(egl_dpy, &egl_major, &egl_minor)) {
printf("Error: eglInitialize() failed\n");
return -1;
}
s = eglQueryString(egl_dpy, EGL_VERSION);
printf("EGL_VERSION = %s\n", s);
s = eglQueryString(egl_dpy, EGL_VENDOR);
printf("EGL_VENDOR = %s\n", s);
s = eglQueryString(egl_dpy, EGL_EXTENSIONS);
printf("EGL_EXTENSIONS = %s\n", s);
s = eglQueryString(egl_dpy, EGL_CLIENT_APIS);
printf("EGL_CLIENT_APIS = %s\n", s);
make_x_window(x_dpy, egl_dpy,
"OpenGL ES 2.x tri", 0, 0, winWidth, winHeight,
&win, &egl_ctx, &egl_surf);
XMapWindow(x_dpy, win);
if (!eglMakeCurrent(egl_dpy, egl_surf, egl_surf, egl_ctx)) {
printf("Error: eglMakeCurrent() failed\n");
return -1;
}
if (printInfo) {
printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
printf("GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR));
printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
}
init();
/* Set initial projection/viewing transformation.
* We can't be sure we'll get a ConfigureNotify event when the window
* first appears.
*/
reshape(winWidth, winHeight);
event_loop(x_dpy, win, egl_dpy, egl_surf);
eglDestroyContext(egl_dpy, egl_ctx);
eglDestroySurface(egl_dpy, egl_surf);
eglTerminate(egl_dpy);
XDestroyWindow(x_dpy, win);
XCloseDisplay(x_dpy);
return 0;
}
|