1 #define GL_GLEXT_PROTOTYPES 1
6 #define BUFFER_OFFSET(i) ((char *)NULL + (i))
8 #define HSV_WHEEL_SIZE 128
14 #include <SDL/SDL_opengl.h>
15 #include <SDL/SDL_image.h>
23 #define check_error() { int err = glGetError(); if (err != GL_NO_ERROR) { printf("GL error 0x%x at line %d\n", err, __LINE__); exit(1); } }
26 unsigned char result[WIDTH * HEIGHT * 4];
28 float lift_theta = 0.0f, lift_rad = 0.0f, lift_v = 0.0f;
29 float gamma_theta = 0.0f, gamma_rad = 0.0f, gamma_v = 0.5f;
30 float gain_theta = 0.0f, gain_rad = 0.0f, gain_v = 0.25f;
31 float saturation = 1.0f;
33 float lift_r = 0.0f, lift_g = 0.0f, lift_b = 0.0f;
34 float gamma_r = 1.0f, gamma_g = 1.0f, gamma_b = 1.0f;
35 float gain_r = 1.0f, gain_g = 1.0f, gain_b = 1.0f;
44 // assumes h in [0, 2pi> or [-pi, pi>
45 void hsv2rgb(float h, float s, float v, float *r, float *g, float *b)
51 float hp = (h * 180.0 / M_PI) / 60.0;
52 float x = c * (1 - fabs(fmod(hp, 2.0f) - 1.0f));
54 if (hp >= 0 && hp < 1) {
58 } else if (hp >= 1 && hp < 2) {
62 } else if (hp >= 2 && hp < 3) {
66 } else if (hp >= 3 && hp < 4) {
70 } else if (hp >= 4 && hp < 5) {
86 GLhandleARB read_shader(const char* filename, GLenum type)
88 static char buf[131072];
89 FILE *fp = fopen(filename, "r");
95 int len = fread(buf, 1, sizeof(buf), fp);
98 GLhandleARB obj = glCreateShaderObjectARB(type);
99 const GLchar* source[] = { buf };
100 const GLint length[] = { len };
101 glShaderSource(obj, 1, source, length);
102 glCompileShader(obj);
104 GLchar info_log[4096];
105 GLsizei log_length = sizeof(info_log) - 1;
106 glGetShaderInfoLog(obj, log_length, &log_length, info_log);
107 info_log[log_length] = 0;
108 printf("shader compile log: %s\n", info_log);
111 glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
112 if (status == GL_FALSE) {
119 void draw_picture_quad(GLint prog, int frame)
121 glUseProgramObjectARB(prog);
124 glActiveTexture(GL_TEXTURE0);
125 glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
126 glUniform1i(glGetUniformLocation(prog, "tex"), 0);
128 glActiveTexture(GL_TEXTURE1);
129 glBindTexture(GL_TEXTURE_1D, SRGB_LUT);
130 glUniform1i(glGetUniformLocation(prog, "srgb_tex"), 1);
132 glActiveTexture(GL_TEXTURE2);
133 glBindTexture(GL_TEXTURE_1D, SRGB_REVERSE_LUT);
134 glUniform1i(glGetUniformLocation(prog, "srgb_reverse_tex"), 2);
136 glUniform3f(glGetUniformLocation(prog, "lift"), lift_r, lift_g, lift_b);
137 //glUniform3f(glGetUniformLocation(prog, "gamma"), gamma_r, gamma_g, gamma_b);
138 glUniform3f(glGetUniformLocation(prog, "inv_gamma_22"),
142 glUniform3f(glGetUniformLocation(prog, "gain_pow_inv_gamma"),
143 pow(gain_r, 1.0f / gamma_r),
144 pow(gain_g, 1.0f / gamma_g),
145 pow(gain_b, 1.0f / gamma_b));
146 glUniform1f(glGetUniformLocation(prog, "saturation"), saturation);
150 glDisable(GL_DEPTH_TEST);
152 glDepthMask(GL_FALSE);
155 glMatrixMode(GL_PROJECTION);
157 glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
159 glMatrixMode(GL_MODELVIEW);
162 glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
163 // glClear(GL_COLOR_BUFFER_BIT);
168 glTexCoord2f(0.0f, 1.0f);
169 glVertex2f(0.0f, 0.0f);
171 glTexCoord2f(1.0f, 1.0f);
172 glVertex2f(1.0f, 0.0f);
174 glTexCoord2f(1.0f, 0.0f);
175 glVertex2f(1.0f, 1.0f);
177 glTexCoord2f(0.0f, 0.0f);
178 glVertex2f(0.0f, 1.0f);
184 void draw_hsv_wheel(float y, float rad, float theta, float value)
186 glUseProgramObjectARB(0);
188 glActiveTexture(GL_TEXTURE0);
190 glEnable(GL_TEXTURE_2D);
192 glBindTexture(GL_TEXTURE_2D, HSV_WHEEL);
194 glActiveTexture(GL_TEXTURE1);
196 glBindTexture(GL_TEXTURE_2D, 0);
198 glActiveTexture(GL_TEXTURE0);
201 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
207 glTexCoord2f(0.0f, 1.0f);
210 glTexCoord2f(1.0f, 1.0f);
211 glVertex2f(0.2f * 9.0f / 16.0f, y);
213 glTexCoord2f(1.0f, 0.0f);
214 glVertex2f(0.2f * 9.0f / 16.0f, y + 0.2f);
216 glTexCoord2f(0.0f, 0.0f);
217 glVertex2f(0.0f, y + 0.2f);
222 glDisable(GL_TEXTURE_2D);
223 glColor3f(0.0f, 0.0f, 0.0f);
226 glVertex2f((0.1f + rad * cos(theta) * 0.1f) * 9.0f / 16.0f, y + 0.1f - rad * sin(theta) * 0.1f);
230 glDisable(GL_TEXTURE_2D);
233 glColor3f(0.0f, 0.0f, 0.0f);
234 glVertex2f(0.22f * 9.0f / 16.0f, y);
235 glVertex2f(0.24f * 9.0f / 16.0f, y);
237 glColor3f(1.0f, 1.0f, 1.0f);
238 glVertex2f(0.24f * 9.0f / 16.0f, y + 0.2f);
239 glVertex2f(0.22f * 9.0f / 16.0f, y + 0.2f);
244 glColor3f(0.0f, 0.0f, 0.0f);
247 glVertex2f(0.23f * 9.0f / 16.0f, y + value * 0.2f);
250 glColor3f(1.0f, 1.0f, 1.0f);
253 void draw_saturation_bar(float y)
255 glUseProgramObjectARB(0);
259 glDisable(GL_TEXTURE_2D);
262 glColor3f(0.0f, 0.0f, 0.0f);
263 glVertex2f(0.0f * 9.0f / 16.0f, y + 0.02f);
264 glVertex2f(0.0f * 9.0f / 16.0f, y);
266 glColor3f(1.0f, 1.0f, 1.0f);
267 glVertex2f(0.2f * 9.0f / 16.0f, y);
268 glVertex2f(0.2f * 9.0f / 16.0f, y + 0.02f);
273 glColor3f(0.0f, 0.0f, 0.0f);
276 glVertex2f(0.2f * (saturation / 4.0f) * 9.0f / 16.0f, y + 0.01f);
279 glColor3f(1.0f, 1.0f, 1.0f);
282 void make_hsv_wheel_texture()
284 static unsigned char hsv_pix[HSV_WHEEL_SIZE * HSV_WHEEL_SIZE * 4];
285 for (int y = 0; y < HSV_WHEEL_SIZE; ++y) {
286 for (int x = 0; x < HSV_WHEEL_SIZE; ++x) {
287 float yf = 2.0f * y / (float)(HSV_WHEEL_SIZE) - 1.0f;
288 float xf = 2.0f * x / (float)(HSV_WHEEL_SIZE) - 1.0f;
289 float rad = hypot(xf, yf);
290 float theta = atan2(yf, xf);
293 hsv2rgb(theta, rad, 1.0f, &r, &g, &b);
294 hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 0] = lrintf(r * 255.0f);
295 hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 1] = lrintf(g * 255.0f);
296 hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 2] = lrintf(b * 255.0f);
299 hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 3] = 0;
301 hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 3] = 255;
307 glBindTexture(GL_TEXTURE_2D, HSV_WHEEL);
309 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
311 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, HSV_WHEEL_SIZE, HSV_WHEEL_SIZE, 0, GL_RGBA, GL_UNSIGNED_BYTE, hsv_pix);
317 hsv2rgb(lift_theta, lift_rad, lift_v, &lift_r, &lift_g, &lift_b);
318 hsv2rgb(gamma_theta, gamma_rad, gamma_v * 2.0f, &gamma_r, &gamma_g, &gamma_b);
319 hsv2rgb(gain_theta, gain_rad, gain_v * 4.0f, &gain_r, &gain_g, &gain_b);
321 if (saturation < 0.0) {
325 printf("lift: %f %f %f\n", lift_r, lift_g, lift_b);
326 printf("gamma: %f %f %f\n", gamma_r, gamma_g, gamma_b);
327 printf("gain: %f %f %f\n", gain_r, gain_g, gain_b);
328 printf("saturation: %f\n", saturation);
332 void read_colorwheel(float xf, float yf, float *rad, float *theta, float *value)
334 if (xf < 0.2f && yf < 0.2f) {
335 float xp = 2.0f * xf / 0.2f - 1.0f;
336 float yp = -(2.0f * yf / 0.2f - 1.0f);
337 *rad = hypot(xp, yp);
338 *theta = atan2(yp, xp);
342 } else if (xf >= 0.22f && xf <= 0.24f) {
347 void mouse(int x, int y)
349 float xf = (x / (float)WIDTH) * 16.0f / 9.0f;
350 float yf = (HEIGHT - y) / (float)HEIGHT;
353 read_colorwheel(xf, yf, &lift_rad, &lift_theta, &lift_v);
354 } else if (yf >= 0.2f && yf < 0.4f) {
355 read_colorwheel(xf, yf - 0.2f, &gamma_rad, &gamma_theta, &gamma_v);
356 } else if (yf >= 0.4f && yf < 0.6f) {
357 read_colorwheel(xf, yf - 0.4f, &gain_rad, &gain_theta, &gain_v);
358 } else if (yf >= 0.6f && yf < 0.62f && xf < 0.2f) {
359 saturation = (xf / 0.2f) * 4.0f;
365 void load_texture(const char *filename)
367 SDL_Surface *img = IMG_Load(filename);
369 fprintf(stderr, "Load of '%s' failed\n", filename);
374 SDL_PixelFormat *fmt = img->format;
375 SDL_LockSurface(img);
376 unsigned char *src_pixels = (unsigned char *)img->pixels;
377 unsigned char *dst_pixels = (unsigned char *)malloc(img->w * img->h * 3);
378 for (unsigned i = 0; i < img->w * img->h; ++i) {
379 unsigned char r, g, b;
381 unsigned int pixel = *(unsigned int *)(src_pixels + i * fmt->BytesPerPixel);
383 temp = pixel & fmt->Rmask;
384 temp = temp >> fmt->Rshift;
385 temp = temp << fmt->Rloss;
388 temp = pixel & fmt->Gmask;
389 temp = temp >> fmt->Gshift;
390 temp = temp << fmt->Gloss;
393 temp = pixel & fmt->Bmask;
394 temp = temp >> fmt->Bshift;
395 temp = temp << fmt->Bloss;
398 dst_pixels[i * 3 + 0] = r;
399 dst_pixels[i * 3 + 1] = g;
400 dst_pixels[i * 3 + 2] = b;
402 SDL_UnlockSurface(img);
405 // we will convert to sRGB in the shader
406 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, img->w, img->h, 0, GL_RGB, GL_UNSIGNED_BYTE, dst_pixels);
409 // implicit sRGB conversion in hardware
410 glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8, img->w, img->h, 0, GL_RGB, GL_UNSIGNED_BYTE, dst_pixels);
414 SDL_FreeSurface(img);
417 void write_ppm(const char *filename, unsigned char *screenbuf)
419 FILE *fp = fopen(filename, "w");
420 fprintf(fp, "P6\n%d %d\n255\n", WIDTH, HEIGHT);
421 for (unsigned y = 0; y < HEIGHT; ++y) {
422 unsigned char *srcptr = screenbuf + ((HEIGHT - y - 1) * WIDTH) * 4;
423 for (unsigned x = 0; x < WIDTH; ++x) {
424 fputc(srcptr[x * 4 + 2], fp);
425 fputc(srcptr[x * 4 + 1], fp);
426 fputc(srcptr[x * 4 + 0], fp);
432 int main(int argc, char **argv)
436 SDL_Init(SDL_INIT_EVERYTHING);
437 SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 0);
438 SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 0);
439 SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
440 SDL_SetVideoMode(WIDTH, HEIGHT, 0, SDL_OPENGL);
441 SDL_WM_SetCaption("OpenGL window", NULL);
444 glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
445 glPixelStorei(GL_PACK_ALIGNMENT, 1);
447 glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
449 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
452 load_texture("blg_wheels_woman_1.jpg");
453 //glGenerateMipmap(GL_TEXTURE_2D);
454 //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 4);
457 //load_texture("maserati_gts_wallpaper_1280x720_01.jpg");
458 //load_texture("90630d1295075297-console-games-wallpapers-wallpaper_need_for_speed_prostreet_09_1920x1080.jpg");
459 //load_texture("glacier-lake-1280-720-4087.jpg");
463 glBindTexture(GL_TEXTURE_1D, SRGB_REVERSE_LUT);
465 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
466 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
468 float srgb_reverse_tex[4096];
469 for (unsigned i = 0; i < 4096; ++i) {
470 float x = i / 4095.0;
471 if (x < 0.0031308f) {
472 srgb_reverse_tex[i] = 12.92f * x;
474 srgb_reverse_tex[i] = 1.055f * pow(x, 1.0f / 2.4f) - 0.055f;
477 glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE16F_ARB, 4096, 0, GL_LUMINANCE, GL_FLOAT, srgb_reverse_tex);
481 glBindTexture(GL_TEXTURE_1D, SRGB_LUT);
483 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
484 glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
487 for (unsigned i = 0; i < 256; ++i) {
490 srgb_tex[i] = x * (1.0f / 12.92f);
492 srgb_tex[i] = pow((x + 0.055) * (1.0 / 1.055f), 2.4);
495 glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE16F_ARB, 256, 0, GL_LUMINANCE, GL_FLOAT, srgb_tex);
499 // generate a PDO to hold the data we read back with glReadPixels()
500 // (Intel/DRI goes into a slow path if we don't read to PDO)
501 glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 1);
502 glBufferData(GL_PIXEL_PACK_BUFFER_ARB, WIDTH * HEIGHT * 4, NULL, GL_STREAM_READ);
504 make_hsv_wheel_texture();
507 int prog = glCreateProgram();
508 GLhandleARB vs_obj = read_shader("vs.glsl", GL_VERTEX_SHADER);
509 GLhandleARB fs_obj = read_shader("fs.glsl", GL_FRAGMENT_SHADER);
510 glAttachObjectARB(prog, vs_obj);
512 glAttachObjectARB(prog, fs_obj);
517 GLchar info_log[4096];
518 GLsizei log_length = sizeof(info_log) - 1;
519 log_length = sizeof(info_log) - 1;
520 glGetProgramInfoLog(prog, log_length, &log_length, info_log);
521 info_log[log_length] = 0;
522 printf("link: %s\n", info_log);
524 struct timespec start, now;
525 int frame = 0, screenshot = 0;
526 clock_gettime(CLOCK_MONOTONIC, &start);
530 while (SDL_PollEvent(&event)) {
531 if (event.type == SDL_QUIT) {
533 } else if (event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_ESCAPE) {
535 } else if (event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_F1) {
537 } else if (event.type == SDL_MOUSEBUTTONDOWN && event.button.button == SDL_BUTTON_LEFT) {
538 mouse(event.button.x, event.button.y);
539 } else if (event.type == SDL_MOUSEMOTION && (event.motion.state & SDL_BUTTON(1))) {
540 mouse(event.motion.x, event.motion.y);
546 draw_picture_quad(prog, frame);
548 glReadPixels(0, 0, WIDTH, HEIGHT, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, BUFFER_OFFSET(0));
551 draw_hsv_wheel(0.0f, lift_rad, lift_theta, lift_v);
552 draw_hsv_wheel(0.2f, gamma_rad, gamma_theta, gamma_v);
553 draw_hsv_wheel(0.4f, gain_rad, gain_theta, gain_v);
554 draw_saturation_bar(0.6f);
556 SDL_GL_SwapBuffers();
559 unsigned char *screenbuf = (unsigned char *)glMapBuffer(GL_PIXEL_PACK_BUFFER_ARB, GL_READ_ONLY);
563 sprintf(filename, "frame%05d.ppm", frame);
564 write_ppm(filename, screenbuf);
565 printf("Screenshot: %s\n", filename);
568 glUnmapBuffer(GL_PIXEL_PACK_BUFFER_ARB);
572 clock_gettime(CLOCK_MONOTONIC, &now);
573 double elapsed = now.tv_sec - start.tv_sec +
574 1e-9 * (now.tv_nsec - start.tv_nsec);
575 printf("%d frames in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
576 frame, elapsed, frame / elapsed,
577 1e3 * elapsed / frame);