oculus2_psprite
view src/main.c @ 10:3d224ad45cac
linux fixes
| author | John Tsiombikas <nuclear@member.fsf.org> |
|---|---|
| date | Sun, 26 Oct 2014 23:10:14 +0200 |
| parents | 9c36ae39ad95 |
| children | 256d8fcf02f1 |
line source
1 /* Very simple OculusSDK OpenGL usage example.
2 *
3 * Uses SDL2 (www.libsdl.org) for event handling and OpenGL context management.
4 * Uses GLEW (glew.sourceforge.net) for OpenGL extension wrangling.
5 *
6 * Author: John Tsiombikas <nuclear@member.fsf.org>
7 * This code is in the public domain. Do whatever you like with it.
8 */
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <assert.h>
12 #include <SDL2/SDL.h>
13 #include <GL/glew.h>
14 #include <X11/Xlib.h>
15 #include <GL/glx.h>
17 #ifdef WIN32
18 #define OVR_OS_WIN32
19 #elif defined(__APPLE__)
20 #define OVR_OS_MAC
21 #else
22 #define OVR_OS_LINUX
23 #endif
25 #include <OVR_CAPI.h>
26 #include <OVR_CAPI_GL.h>
28 int init(void);
29 void cleanup(void);
30 void toggle_hmd_fullscreen(void);
31 void display(void);
32 void draw_scene(void);
33 void draw_box(float xsz, float ysz, float zsz, float norm_sign);
34 void update_rtarg(int width, int height);
35 int handle_event(SDL_Event *ev);
36 int key_event(int key, int state);
37 void reshape(int x, int y);
38 unsigned int next_pow2(unsigned int x);
39 void quat_to_matrix(const float *quat, float *mat);
40 unsigned int gen_chess_tex(float r0, float g0, float b0, float r1, float g1, float b1);
42 /* forward declaration to avoid including non-public headers of libovr */
43 OVR_EXPORT void ovrhmd_EnableHSWDisplaySDKRender(ovrHmd hmd, ovrBool enable);
45 static SDL_Window *win;
46 static SDL_GLContext ctx;
47 static int win_width, win_height;
49 static unsigned int fbo, fb_tex, fb_depth;
50 static int fb_width, fb_height;
51 static int fb_tex_width, fb_tex_height;
53 static ovrHmd hmd;
54 static ovrSizei eyeres[2];
55 static ovrEyeRenderDesc eye_rdesc[2];
56 static ovrGLTexture fb_ovr_tex[2];
58 static unsigned int chess_tex;
61 int main(int argc, char **argv)
62 {
63 if(init() == -1) {
64 return 1;
65 }
67 for(;;) {
68 SDL_Event ev;
69 while(SDL_PollEvent(&ev)) {
70 if(handle_event(&ev) == -1) {
71 goto done;
72 }
73 }
74 display();
75 }
77 done:
78 cleanup();
79 return 0;
80 }
83 int init(void)
84 {
85 int i, x, y;
86 unsigned int flags, dcaps;
87 union ovrGLConfig glcfg;
89 /* libovr must be initialized before we create the OpenGL context */
90 ovr_Initialize();
92 SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER);
94 x = y = SDL_WINDOWPOS_UNDEFINED;
95 flags = SDL_WINDOW_OPENGL;
96 if(!(win = SDL_CreateWindow("press 'f' to move to the HMD", x, y, 1280, 800, flags))) {
97 fprintf(stderr, "failed to create window\n");
98 return -1;
99 }
100 if(!(ctx = SDL_GL_CreateContext(win))) {
101 fprintf(stderr, "failed to create OpenGL context\n");
102 return -1;
103 }
105 XSynchronize(glXGetCurrentDisplay(), True);
107 glewInit();
109 if(!(hmd = ovrHmd_Create(0))) {
110 fprintf(stderr, "failed to open Oculus HMD, falling back to virtual debug HMD\n");
111 if(!(hmd = ovrHmd_CreateDebug(ovrHmd_DK2))) {
112 fprintf(stderr, "failed to create virtual debug HMD\n");
113 return -1;
114 }
115 }
116 printf("initialized HMD: %s - %s\n", hmd->Manufacturer, hmd->ProductName);
118 /* resize our window to match the HMD resolution */
119 SDL_SetWindowSize(win, hmd->Resolution.w, hmd->Resolution.h);
120 SDL_SetWindowPosition(win, SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED);
121 win_width = hmd->Resolution.w;
122 win_height = hmd->Resolution.h;
124 /* enable position and rotation tracking (and anything else they might add in the future) */
125 ovrHmd_ConfigureTracking(hmd, 0xffffffff, 0);
126 /* retrieve the optimal render target resolution for each eye */
127 eyeres[0] = ovrHmd_GetFovTextureSize(hmd, ovrEye_Left, hmd->DefaultEyeFov[0], 1.0);
128 eyeres[1] = ovrHmd_GetFovTextureSize(hmd, ovrEye_Right, hmd->DefaultEyeFov[1], 1.0);
130 /* and create a single render target texture to encompass both eyes */
131 fb_width = eyeres[0].w + eyeres[1].w;
132 fb_height = eyeres[0].h > eyeres[1].h ? eyeres[0].h : eyeres[1].h;
133 update_rtarg(fb_width, fb_height);
135 /* fill in the ovrGLTexture structures that describe our render target texture */
136 for(i=0; i<2; i++) {
137 fb_ovr_tex[i].OGL.Header.API = ovrRenderAPI_OpenGL;
138 fb_ovr_tex[i].OGL.Header.TextureSize.w = fb_tex_width;
139 fb_ovr_tex[i].OGL.Header.TextureSize.h = fb_tex_height;
140 /* this next field is the only one that differs between the two eyes */
141 fb_ovr_tex[i].OGL.Header.RenderViewport.Pos.x = i == 0 ? 0 : fb_width / 2.0;
142 fb_ovr_tex[i].OGL.Header.RenderViewport.Pos.y = fb_tex_height - fb_height;
143 fb_ovr_tex[i].OGL.Header.RenderViewport.Size.w = fb_width / 2.0;
144 fb_ovr_tex[i].OGL.Header.RenderViewport.Size.h = fb_height;
145 fb_ovr_tex[i].OGL.TexId = fb_tex; /* both eyes will use the same texture id */
146 }
148 /* fill in the ovrGLConfig structure needed by the SDK to draw our stereo pair
149 * to the actual HMD display (SDK-distortion mode)
150 */
151 memset(&glcfg, 0, sizeof glcfg);
152 glcfg.OGL.Header.API = ovrRenderAPI_OpenGL;
153 glcfg.OGL.Header.RTSize = hmd->Resolution;
154 glcfg.OGL.Header.Multisample = 1;
156 if(hmd->HmdCaps & ovrHmdCap_ExtendDesktop) {
157 printf("running in \"extended desktop\" mode\n");
158 } else {
159 /* to sucessfully draw to the HMD display in "direct-hmd" mode, we have to
160 * call ovrHmd_AttachToWindow
161 * XXX: this doesn't work properly yet due to bugs in the oculus 0.4.1 sdk/driver
162 */
163 #ifdef WIN32
164 HWND sys_win = GetActiveWindow();
165 glcfg.OGL.Window = sys_win;
166 glcfg.OGL.DC = wglGetCurrentDC();
167 ovrHmd_AttachToWindow(hmd, sys_win, 0, 0);
168 #else
169 Display *dpy = glXGetCurrentDisplay();
170 Window win = glXGetCurrentDrawable();
171 assert(dpy && win);
173 glcfg.OGL.Disp = dpy;
174 glcfg.OGL.Win = win;
175 ovrHmd_AttachToWindow(hmd, (void*)win, 0, 0);
176 #endif
177 printf("running in \"direct-hmd\" mode\n");
178 }
180 /* enable low-persistence display and dynamic prediction for lattency compensation */
181 ovrHmd_SetEnabledCaps(hmd, ovrHmdCap_LowPersistence | ovrHmdCap_DynamicPrediction);
183 /* configure SDK-rendering and enable chromatic abberation correction, vignetting, and
184 * timewrap, which shifts the image before drawing to counter any lattency between the call
185 * to ovrHmd_GetEyePose and ovrHmd_EndFrame.
186 */
187 dcaps = ovrDistortionCap_Chromatic | ovrDistortionCap_Vignette | ovrDistortionCap_TimeWarp |
188 ovrDistortionCap_Overdrive;
189 if(!ovrHmd_ConfigureRendering(hmd, &glcfg.Config, dcaps, hmd->DefaultEyeFov, eye_rdesc)) {
190 fprintf(stderr, "failed to configure distortion renderer\n");
191 }
193 /* disable the retarded "health and safety warning" */
194 ovrhmd_EnableHSWDisplaySDKRender(hmd, 0);
196 glEnable(GL_DEPTH_TEST);
197 glEnable(GL_CULL_FACE);
198 glEnable(GL_LIGHTING);
199 glEnable(GL_LIGHT0);
200 glEnable(GL_LIGHT1);
201 glEnable(GL_NORMALIZE);
203 glClearColor(0.1, 0.1, 0.1, 1);
205 chess_tex = gen_chess_tex(1.0, 0.7, 0.4, 0.4, 0.7, 1.0);
206 return 0;
207 }
209 void cleanup(void)
210 {
211 if(hmd) {
212 ovrHmd_Destroy(hmd);
213 }
214 ovr_Shutdown();
216 SDL_Quit();
217 }
219 void toggle_hmd_fullscreen(void)
220 {
221 static int fullscr, prev_x, prev_y;
222 fullscr = !fullscr;
224 if(fullscr) {
225 /* going fullscreen on the rift. save current window position, and move it
226 * to the rift's part of the desktop before going fullscreen
227 */
228 SDL_GetWindowPosition(win, &prev_x, &prev_y);
229 SDL_SetWindowPosition(win, hmd->WindowsPos.x, hmd->WindowsPos.y);
230 SDL_SetWindowFullscreen(win, SDL_WINDOW_FULLSCREEN_DESKTOP);
231 } else {
232 /* return to windowed mode and move the window back to its original position */
233 SDL_SetWindowFullscreen(win, 0);
234 SDL_SetWindowPosition(win, prev_x, prev_y);
235 }
236 }
238 void display(void)
239 {
240 int i;
241 ovrMatrix4f proj;
242 ovrPosef pose[2];
243 float rot_mat[16];
245 /* the drawing starts with a call to ovrHmd_BeginFrame */
246 ovrHmd_BeginFrame(hmd, 0);
248 /* start drawing onto our texture render target */
249 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
250 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
252 /* for each eye ... */
253 for(i=0; i<2; i++) {
254 ovrEyeType eye = hmd->EyeRenderOrder[i];
256 /* -- viewport transformation --
257 * setup the viewport to draw in the left half of the framebuffer when we're
258 * rendering the left eye's view (0, 0, width/2, height), and in the right half
259 * of the framebuffer for the right eye's view (width/2, 0, width/2, height)
260 */
261 glViewport(eye == ovrEye_Left ? 0 : fb_width / 2, 0, fb_width / 2, fb_height);
263 /* -- projection transformation --
264 * we'll just have to use the projection matrix supplied by the oculus SDK for this eye
265 * note that libovr matrices are the transpose of what OpenGL expects, so we have to
266 * use glLoadTransposeMatrixf instead of glLoadMatrixf to load it.
267 */
268 proj = ovrMatrix4f_Projection(hmd->DefaultEyeFov[eye], 0.5, 500.0, 1);
269 glMatrixMode(GL_PROJECTION);
270 glLoadTransposeMatrixf(proj.M[0]);
272 /* -- view/camera transformation --
273 * we need to construct a view matrix by combining all the information provided by the oculus
274 * SDK, about the position and orientation of the user's head in the world.
275 */
276 /* TODO: use ovrHmd_GetEyePoses out of the loop instead */
277 pose[eye] = ovrHmd_GetHmdPosePerEye(hmd, eye);
278 glMatrixMode(GL_MODELVIEW);
279 glLoadIdentity();
280 glTranslatef(eye_rdesc[eye].HmdToEyeViewOffset.x,
281 eye_rdesc[eye].HmdToEyeViewOffset.y,
282 eye_rdesc[eye].HmdToEyeViewOffset.z);
283 /* retrieve the orientation quaternion and convert it to a rotation matrix */
284 quat_to_matrix(&pose[eye].Orientation.x, rot_mat);
285 glMultMatrixf(rot_mat);
286 /* translate the view matrix with the positional tracking */
287 glTranslatef(-pose[eye].Position.x, -pose[eye].Position.y, -pose[eye].Position.z);
288 /* move the camera to the eye level of the user */
289 glTranslatef(0, -ovrHmd_GetFloat(hmd, OVR_KEY_EYE_HEIGHT, 1.65), 0);
291 /* finally draw the scene for this eye */
292 draw_scene();
293 }
295 /* after drawing both eyes into the texture render target, revert to drawing directly to the
296 * display, and we call ovrHmd_EndFrame, to let the Oculus SDK draw both images properly
297 * compensated for lens distortion and chromatic abberation onto the HMD screen.
298 */
299 glBindFramebuffer(GL_FRAMEBUFFER, 0);
300 glViewport(0, 0, win_width, win_height);
302 ovrHmd_EndFrame(hmd, pose, &fb_ovr_tex[0].Texture);
304 assert(glGetError() == GL_NO_ERROR);
305 }
307 void draw_scene(void)
308 {
309 int i;
310 float grey[] = {0.8, 0.8, 0.8, 1};
311 float col[] = {0, 0, 0, 1};
312 float lpos[][4] = {
313 {-8, 2, 10, 1},
314 {0, 15, 0, 1}
315 };
316 float lcol[][4] = {
317 {0.8, 0.8, 0.8, 1},
318 {0.4, 0.3, 0.3, 1}
319 };
321 for(i=0; i<2; i++) {
322 glLightfv(GL_LIGHT0 + i, GL_POSITION, lpos[i]);
323 glLightfv(GL_LIGHT0 + i, GL_DIFFUSE, lcol[i]);
324 }
326 glMatrixMode(GL_MODELVIEW);
328 glPushMatrix();
329 glTranslatef(0, 10, 0);
330 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, grey);
331 glBindTexture(GL_TEXTURE_2D, chess_tex);
332 glEnable(GL_TEXTURE_2D);
333 draw_box(30, 20, 30, -1.0);
334 glDisable(GL_TEXTURE_2D);
335 glPopMatrix();
337 for(i=0; i<4; i++) {
338 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, grey);
339 glPushMatrix();
340 glTranslatef(i & 1 ? 5 : -5, 1, i & 2 ? -5 : 5);
341 draw_box(0.5, 2, 0.5, 1.0);
342 glPopMatrix();
344 col[0] = i & 1 ? 1.0 : 0.3;
345 col[1] = i == 0 ? 1.0 : 0.3;
346 col[2] = i & 2 ? 1.0 : 0.3;
347 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, col);
349 glPushMatrix();
350 if(i & 1) {
351 glTranslatef(0, 0.25, i & 2 ? 2 : -2);
352 } else {
353 glTranslatef(i & 2 ? 2 : -2, 0.25, 0);
354 }
355 draw_box(0.5, 0.5, 0.5, 1.0);
356 glPopMatrix();
357 }
358 }
360 void draw_box(float xsz, float ysz, float zsz, float norm_sign)
361 {
362 glMatrixMode(GL_MODELVIEW);
363 glScalef(xsz * 0.5, ysz * 0.5, zsz * 0.5);
365 if(norm_sign < 0.0) {
366 glFrontFace(GL_CW);
367 }
369 glBegin(GL_QUADS);
370 glNormal3f(0, 0, 1 * norm_sign);
371 glTexCoord2f(0, 0); glVertex3f(-1, -1, 1);
372 glTexCoord2f(1, 0); glVertex3f(1, -1, 1);
373 glTexCoord2f(1, 1); glVertex3f(1, 1, 1);
374 glTexCoord2f(0, 1); glVertex3f(-1, 1, 1);
375 glNormal3f(1 * norm_sign, 0, 0);
376 glTexCoord2f(0, 0); glVertex3f(1, -1, 1);
377 glTexCoord2f(1, 0); glVertex3f(1, -1, -1);
378 glTexCoord2f(1, 1); glVertex3f(1, 1, -1);
379 glTexCoord2f(0, 1); glVertex3f(1, 1, 1);
380 glNormal3f(0, 0, -1 * norm_sign);
381 glTexCoord2f(0, 0); glVertex3f(1, -1, -1);
382 glTexCoord2f(1, 0); glVertex3f(-1, -1, -1);
383 glTexCoord2f(1, 1); glVertex3f(-1, 1, -1);
384 glTexCoord2f(0, 1); glVertex3f(1, 1, -1);
385 glNormal3f(-1 * norm_sign, 0, 0);
386 glTexCoord2f(0, 0); glVertex3f(-1, -1, -1);
387 glTexCoord2f(1, 0); glVertex3f(-1, -1, 1);
388 glTexCoord2f(1, 1); glVertex3f(-1, 1, 1);
389 glTexCoord2f(0, 1); glVertex3f(-1, 1, -1);
390 glEnd();
391 glBegin(GL_TRIANGLE_FAN);
392 glNormal3f(0, 1 * norm_sign, 0);
393 glTexCoord2f(0.5, 0.5); glVertex3f(0, 1, 0);
394 glTexCoord2f(0, 0); glVertex3f(-1, 1, 1);
395 glTexCoord2f(1, 0); glVertex3f(1, 1, 1);
396 glTexCoord2f(1, 1); glVertex3f(1, 1, -1);
397 glTexCoord2f(0, 1); glVertex3f(-1, 1, -1);
398 glTexCoord2f(0, 0); glVertex3f(-1, 1, 1);
399 glEnd();
400 glBegin(GL_TRIANGLE_FAN);
401 glNormal3f(0, -1 * norm_sign, 0);
402 glTexCoord2f(0.5, 0.5); glVertex3f(0, -1, 0);
403 glTexCoord2f(0, 0); glVertex3f(-1, -1, -1);
404 glTexCoord2f(1, 0); glVertex3f(1, -1, -1);
405 glTexCoord2f(1, 1); glVertex3f(1, -1, 1);
406 glTexCoord2f(0, 1); glVertex3f(-1, -1, 1);
407 glTexCoord2f(0, 0); glVertex3f(-1, -1, -1);
408 glEnd();
410 glFrontFace(GL_CCW);
411 }
413 /* update_rtarg creates (and/or resizes) the render target used to draw the two stero views */
414 void update_rtarg(int width, int height)
415 {
416 if(!fbo) {
417 /* if fbo does not exist, then nothing does... create every opengl object */
418 glGenFramebuffers(1, &fbo);
419 glGenTextures(1, &fb_tex);
420 glGenRenderbuffers(1, &fb_depth);
422 glBindTexture(GL_TEXTURE_2D, fb_tex);
423 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
424 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
425 }
427 glBindFramebuffer(GL_FRAMEBUFFER, fbo);
429 /* calculate the next power of two in both dimensions and use that as a texture size */
430 fb_tex_width = next_pow2(width);
431 fb_tex_height = next_pow2(height);
433 /* create and attach the texture that will be used as a color buffer */
434 glBindTexture(GL_TEXTURE_2D, fb_tex);
435 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, fb_tex_width, fb_tex_height, 0,
436 GL_RGBA, GL_UNSIGNED_BYTE, 0);
437 glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, fb_tex, 0);
439 /* create and attach the renderbuffer that will serve as our z-buffer */
440 glBindRenderbuffer(GL_RENDERBUFFER, fb_depth);
441 glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, fb_tex_width, fb_tex_height);
442 glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, fb_depth);
444 if(glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
445 fprintf(stderr, "incomplete framebuffer!\n");
446 }
448 glBindFramebuffer(GL_FRAMEBUFFER, 0);
449 printf("created render target: %dx%d (texture size: %dx%d)\n", width, height, fb_tex_width, fb_tex_height);
450 }
452 int handle_event(SDL_Event *ev)
453 {
454 switch(ev->type) {
455 case SDL_QUIT:
456 return -1;
458 case SDL_KEYDOWN:
459 case SDL_KEYUP:
460 if(key_event(ev->key.keysym.sym, ev->key.state == SDL_PRESSED) == -1) {
461 return -1;
462 }
463 break;
465 default:
466 break;
467 }
469 return 0;
470 }
472 int key_event(int key, int state)
473 {
474 if(state) {
475 /*
476 ovrHSWDisplayState hsw;
477 ovrHmd_GetHSWDisplayState(hmd, &hsw);
478 if(hsw.Displayed) {
479 ovrHmd_DismissHSWDisplay(hmd);
480 }
481 */
483 switch(key) {
484 case 27:
485 return -1;
487 case ' ':
488 /* allow the user to recenter by pressing space */
489 ovrHmd_RecenterPose(hmd);
490 break;
492 case 'f':
493 /* press f to move the window to the HMD */
494 toggle_hmd_fullscreen();
495 break;
497 default:
498 break;
499 }
500 }
501 return 0;
502 }
504 unsigned int next_pow2(unsigned int x)
505 {
506 x -= 1;
507 x |= x >> 1;
508 x |= x >> 2;
509 x |= x >> 4;
510 x |= x >> 8;
511 x |= x >> 16;
512 return x + 1;
513 }
515 /* convert a quaternion to a rotation matrix */
516 void quat_to_matrix(const float *quat, float *mat)
517 {
518 mat[0] = 1.0 - 2.0 * quat[1] * quat[1] - 2.0 * quat[2] * quat[2];
519 mat[4] = 2.0 * quat[0] * quat[1] + 2.0 * quat[3] * quat[2];
520 mat[8] = 2.0 * quat[2] * quat[0] - 2.0 * quat[3] * quat[1];
521 mat[12] = 0.0f;
523 mat[1] = 2.0 * quat[0] * quat[1] - 2.0 * quat[3] * quat[2];
524 mat[5] = 1.0 - 2.0 * quat[0]*quat[0] - 2.0 * quat[2]*quat[2];
525 mat[9] = 2.0 * quat[1] * quat[2] + 2.0 * quat[3] * quat[0];
526 mat[13] = 0.0f;
528 mat[2] = 2.0 * quat[2] * quat[0] + 2.0 * quat[3] * quat[1];
529 mat[6] = 2.0 * quat[1] * quat[2] - 2.0 * quat[3] * quat[0];
530 mat[10] = 1.0 - 2.0 * quat[0]*quat[0] - 2.0 * quat[1]*quat[1];
531 mat[14] = 0.0f;
533 mat[3] = mat[7] = mat[11] = 0.0f;
534 mat[15] = 1.0f;
535 }
537 /* generate a chessboard texture with tiles colored (r0, g0, b0) and (r1, g1, b1) */
538 unsigned int gen_chess_tex(float r0, float g0, float b0, float r1, float g1, float b1)
539 {
540 int i, j;
541 unsigned int tex;
542 unsigned char img[8 * 8 * 3];
543 unsigned char *pix = img;
545 for(i=0; i<8; i++) {
546 for(j=0; j<8; j++) {
547 int black = (i & 1) == (j & 1);
548 pix[0] = (black ? r0 : r1) * 255;
549 pix[1] = (black ? g0 : g1) * 255;
550 pix[2] = (black ? b0 : b1) * 255;
551 pix += 3;
552 }
553 }
555 glGenTextures(1, &tex);
556 glBindTexture(GL_TEXTURE_2D, tex);
557 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
558 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
559 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 8, 8, 0, GL_RGB, GL_UNSIGNED_BYTE, img);
561 return tex;
562 }