--- /dev/null
+#define GL_GLEXT_PROTOTYPES 1
+#define NO_SDL_GLEXT 1
+
+#define WIDTH 1280
+#define HEIGHT 720
+#define BUFFER_OFFSET(i) ((char *)NULL + (i))
+
+#define HSV_WHEEL_SIZE 128
+
+#include <math.h>
+#include <time.h>
+
+#include <SDL/SDL.h>
+#include <SDL/SDL_opengl.h>
+#include <SDL/SDL_image.h>
+
+#include <GL/gl.h>
+#include <GL/glext.h>
+
+#ifdef NDEBUG
+#define check_error()
+#else
+#define check_error() { int err = glGetError(); if (err != GL_NO_ERROR) { printf("GL error 0x%x at line %d\n", err, __LINE__); exit(1); } }
+#endif
+
+unsigned char result[WIDTH * HEIGHT * 4];
+
+float lift_theta = 0.0f, lift_rad = 0.0f, lift_v = 0.0f;
+float gamma_theta = 0.0f, gamma_rad = 0.0f, gamma_v = 0.5f;
+float gain_theta = 0.0f, gain_rad = 0.0f, gain_v = 0.25f;
+float saturation = 1.0f;
+
+float lift_r = 0.0f, lift_g = 0.0f, lift_b = 0.0f;
+float gamma_r = 1.0f, gamma_g = 1.0f, gamma_b = 1.0f;
+float gain_r = 1.0f, gain_g = 1.0f, gain_b = 1.0f;
+
+enum textures {
+ SOURCE_IMAGE = 1,
+ SRGB_LUT = 2,
+ SRGB_REVERSE_LUT = 3,
+ HSV_WHEEL = 4,
+};
+
+// assumes h in [0, 2pi> or [-pi, pi>
+void hsv2rgb(float h, float s, float v, float *r, float *g, float *b)
+{
+ if (h < 0.0f) {
+ h += 2.0f * M_PI;
+ }
+ float c = v * s;
+ float hp = (h * 180.0 / M_PI) / 60.0;
+ float x = c * (1 - fabs(fmod(hp, 2.0f) - 1.0f));
+
+ if (hp >= 0 && hp < 1) {
+ *r = c;
+ *g = x;
+ *b = 0.0f;
+ } else if (hp >= 1 && hp < 2) {
+ *r = x;
+ *g = c;
+ *b = 0.0f;
+ } else if (hp >= 2 && hp < 3) {
+ *r = 0.0f;
+ *g = c;
+ *b = x;
+ } else if (hp >= 3 && hp < 4) {
+ *r = 0.0f;
+ *g = x;
+ *b = c;
+ } else if (hp >= 4 && hp < 5) {
+ *r = x;
+ *g = 0.0f;
+ *b = c;
+ } else {
+ *r = c;
+ *g = 0.0f;
+ *b = x;
+ }
+
+ float m = v - c;
+ *r += m;
+ *g += m;
+ *b += m;
+}
+
+GLhandleARB read_shader(const char* filename, GLenum type)
+{
+ static char buf[131072];
+ FILE *fp = fopen(filename, "r");
+ if (fp == NULL) {
+ perror(filename);
+ exit(1);
+ }
+
+ int len = fread(buf, 1, sizeof(buf), fp);
+ fclose(fp);
+
+ GLhandleARB obj = glCreateShaderObjectARB(type);
+ const GLchar* source[] = { buf };
+ const GLint length[] = { len };
+ glShaderSource(obj, 1, source, length);
+ glCompileShader(obj);
+
+ GLchar info_log[4096];
+ GLsizei log_length = sizeof(info_log) - 1;
+ glGetShaderInfoLog(obj, log_length, &log_length, info_log);
+ info_log[log_length] = 0;
+ printf("shader compile log: %s\n", info_log);
+
+ GLint status;
+ glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
+ if (status == GL_FALSE) {
+ exit(1);
+ }
+
+ return obj;
+}
+
+void draw_picture_quad(GLint prog, int frame)
+{
+ glUseProgramObjectARB(prog);
+ check_error();
+
+ glActiveTexture(GL_TEXTURE0);
+ glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
+ glUniform1i(glGetUniformLocation(prog, "tex"), 0);
+
+ glActiveTexture(GL_TEXTURE1);
+ glBindTexture(GL_TEXTURE_1D, SRGB_LUT);
+ glUniform1i(glGetUniformLocation(prog, "srgb_tex"), 1);
+
+ glActiveTexture(GL_TEXTURE2);
+ glBindTexture(GL_TEXTURE_1D, SRGB_REVERSE_LUT);
+ glUniform1i(glGetUniformLocation(prog, "srgb_reverse_tex"), 2);
+
+ glUniform3f(glGetUniformLocation(prog, "lift"), lift_r, lift_g, lift_b);
+ //glUniform3f(glGetUniformLocation(prog, "gamma"), gamma_r, gamma_g, gamma_b);
+ glUniform3f(glGetUniformLocation(prog, "inv_gamma_22"),
+ 2.2f / gamma_r,
+ 2.2f / gamma_g,
+ 2.2f / gamma_b);
+ glUniform3f(glGetUniformLocation(prog, "gain_pow_inv_gamma"),
+ pow(gain_r, 1.0f / gamma_r),
+ pow(gain_g, 1.0f / gamma_g),
+ pow(gain_b, 1.0f / gamma_b));
+ glUniform1f(glGetUniformLocation(prog, "saturation"), saturation);
+
+ glDisable(GL_BLEND);
+ check_error();
+ glDisable(GL_DEPTH_TEST);
+ check_error();
+ glDepthMask(GL_FALSE);
+ check_error();
+
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
+
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+
+ glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
+// glClear(GL_COLOR_BUFFER_BIT);
+ check_error();
+
+ glBegin(GL_QUADS);
+
+ glTexCoord2f(0.0f, 1.0f);
+ glVertex2f(0.0f, 0.0f);
+
+ glTexCoord2f(1.0f, 1.0f);
+ glVertex2f(1.0f, 0.0f);
+
+ glTexCoord2f(1.0f, 0.0f);
+ glVertex2f(1.0f, 1.0f);
+
+ glTexCoord2f(0.0f, 0.0f);
+ glVertex2f(0.0f, 1.0f);
+
+ glEnd();
+ check_error();
+}
+
+void draw_hsv_wheel(float y, float rad, float theta, float value)
+{
+ glUseProgramObjectARB(0);
+ check_error();
+ glActiveTexture(GL_TEXTURE0);
+ check_error();
+ glEnable(GL_TEXTURE_2D);
+ check_error();
+ glBindTexture(GL_TEXTURE_2D, HSV_WHEEL);
+ check_error();
+ glActiveTexture(GL_TEXTURE1);
+ check_error();
+ glBindTexture(GL_TEXTURE_2D, 0);
+ check_error();
+ glActiveTexture(GL_TEXTURE0);
+ glEnable(GL_BLEND);
+ check_error();
+ glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+ check_error();
+
+ // wheel
+ glBegin(GL_QUADS);
+
+ glTexCoord2f(0.0f, 1.0f);
+ glVertex2f(0.0f, y);
+
+ glTexCoord2f(1.0f, 1.0f);
+ glVertex2f(0.2f * 9.0f / 16.0f, y);
+
+ glTexCoord2f(1.0f, 0.0f);
+ glVertex2f(0.2f * 9.0f / 16.0f, y + 0.2f);
+
+ glTexCoord2f(0.0f, 0.0f);
+ glVertex2f(0.0f, y + 0.2f);
+
+ glEnd();
+
+ // wheel selector
+ glDisable(GL_TEXTURE_2D);
+ glColor3f(0.0f, 0.0f, 0.0f);
+ glPointSize(5.0f);
+ glBegin(GL_POINTS);
+ glVertex2f((0.1f + rad * cos(theta) * 0.1f) * 9.0f / 16.0f, y + 0.1f - rad * sin(theta) * 0.1f);
+ glEnd();
+
+ // value slider
+ glDisable(GL_TEXTURE_2D);
+ glBegin(GL_QUADS);
+
+ glColor3f(0.0f, 0.0f, 0.0f);
+ glVertex2f(0.22f * 9.0f / 16.0f, y);
+ glVertex2f(0.24f * 9.0f / 16.0f, y);
+
+ glColor3f(1.0f, 1.0f, 1.0f);
+ glVertex2f(0.24f * 9.0f / 16.0f, y + 0.2f);
+ glVertex2f(0.22f * 9.0f / 16.0f, y + 0.2f);
+
+ glEnd();
+
+ // value selector
+ glColor3f(0.0f, 0.0f, 0.0f);
+ glPointSize(5.0f);
+ glBegin(GL_POINTS);
+ glVertex2f(0.23f * 9.0f / 16.0f, y + value * 0.2f);
+ glEnd();
+
+ glColor3f(1.0f, 1.0f, 1.0f);
+}
+
+void draw_saturation_bar(float y)
+{
+ glUseProgramObjectARB(0);
+ check_error();
+
+ // value slider
+ glDisable(GL_TEXTURE_2D);
+ glBegin(GL_QUADS);
+
+ glColor3f(0.0f, 0.0f, 0.0f);
+ glVertex2f(0.0f * 9.0f / 16.0f, y + 0.02f);
+ glVertex2f(0.0f * 9.0f / 16.0f, y);
+
+ glColor3f(1.0f, 1.0f, 1.0f);
+ glVertex2f(0.2f * 9.0f / 16.0f, y);
+ glVertex2f(0.2f * 9.0f / 16.0f, y + 0.02f);
+
+ glEnd();
+
+ // value selector
+ glColor3f(0.0f, 0.0f, 0.0f);
+ glPointSize(5.0f);
+ glBegin(GL_POINTS);
+ glVertex2f(0.2f * (saturation / 4.0f) * 9.0f / 16.0f, y + 0.01f);
+ glEnd();
+
+ glColor3f(1.0f, 1.0f, 1.0f);
+}
+
+void make_hsv_wheel_texture()
+{
+ static unsigned char hsv_pix[HSV_WHEEL_SIZE * HSV_WHEEL_SIZE * 4];
+ for (int y = 0; y < HSV_WHEEL_SIZE; ++y) {
+ for (int x = 0; x < HSV_WHEEL_SIZE; ++x) {
+ float yf = 2.0f * y / (float)(HSV_WHEEL_SIZE) - 1.0f;
+ float xf = 2.0f * x / (float)(HSV_WHEEL_SIZE) - 1.0f;
+ float rad = hypot(xf, yf);
+ float theta = atan2(yf, xf);
+
+ float r, g, b;
+ hsv2rgb(theta, rad, 1.0f, &r, &g, &b);
+ hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 0] = lrintf(r * 255.0f);
+ hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 1] = lrintf(g * 255.0f);
+ hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 2] = lrintf(b * 255.0f);
+
+ if (rad > 1.0f) {
+ hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 3] = 0;
+ } else {
+ hsv_pix[(y * HSV_WHEEL_SIZE + x) * 4 + 3] = 255;
+ }
+ }
+ printf("\n");
+ }
+
+ glBindTexture(GL_TEXTURE_2D, HSV_WHEEL);
+ check_error();
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ check_error();
+ glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, HSV_WHEEL_SIZE, HSV_WHEEL_SIZE, 0, GL_RGBA, GL_UNSIGNED_BYTE, hsv_pix);
+ check_error();
+}
+
+void update_hsv()
+{
+ hsv2rgb(lift_theta, lift_rad, lift_v, &lift_r, &lift_g, &lift_b);
+ hsv2rgb(gamma_theta, gamma_rad, gamma_v * 2.0f, &gamma_r, &gamma_g, &gamma_b);
+ hsv2rgb(gain_theta, gain_rad, gain_v * 4.0f, &gain_r, &gain_g, &gain_b);
+
+ if (saturation < 0.0) {
+ saturation = 0.0;
+ }
+
+ printf("lift: %f %f %f\n", lift_r, lift_g, lift_b);
+ printf("gamma: %f %f %f\n", gamma_r, gamma_g, gamma_b);
+ printf("gain: %f %f %f\n", gain_r, gain_g, gain_b);
+ printf("saturation: %f\n", saturation);
+ printf("\n");
+}
+
+void read_colorwheel(float xf, float yf, float *rad, float *theta, float *value)
+{
+ if (xf < 0.2f && yf < 0.2f) {
+ float xp = 2.0f * xf / 0.2f - 1.0f;
+ float yp = -(2.0f * yf / 0.2f - 1.0f);
+ *rad = hypot(xp, yp);
+ *theta = atan2(yp, xp);
+ if (*rad > 1.0) {
+ *rad = 1.0;
+ }
+ } else if (xf >= 0.22f && xf <= 0.24f) {
+ *value = yf / 0.2f;
+ }
+}
+
+void mouse(int x, int y)
+{
+ float xf = (x / (float)WIDTH) * 16.0f / 9.0f;
+ float yf = (HEIGHT - y) / (float)HEIGHT;
+
+ if (yf < 0.2f) {
+ read_colorwheel(xf, yf, &lift_rad, &lift_theta, &lift_v);
+ } else if (yf >= 0.2f && yf < 0.4f) {
+ read_colorwheel(xf, yf - 0.2f, &gamma_rad, &gamma_theta, &gamma_v);
+ } else if (yf >= 0.4f && yf < 0.6f) {
+ read_colorwheel(xf, yf - 0.4f, &gain_rad, &gain_theta, &gain_v);
+ } else if (yf >= 0.6f && yf < 0.62f && xf < 0.2f) {
+ saturation = (xf / 0.2f) * 4.0f;
+ }
+
+ update_hsv();
+}
+
+void load_texture(const char *filename)
+{
+ SDL_Surface *img = IMG_Load(filename);
+ if (img == NULL) {
+ fprintf(stderr, "Load of '%s' failed\n", filename);
+ exit(1);
+ }
+
+ // Convert to RGB.
+ SDL_PixelFormat *fmt = img->format;
+ SDL_LockSurface(img);
+ unsigned char *src_pixels = (unsigned char *)img->pixels;
+ unsigned char *dst_pixels = (unsigned char *)malloc(img->w * img->h * 3);
+ for (unsigned i = 0; i < img->w * img->h; ++i) {
+ unsigned char r, g, b;
+ unsigned int temp;
+ unsigned int pixel = *(unsigned int *)(src_pixels + i * fmt->BytesPerPixel);
+
+ temp = pixel & fmt->Rmask;
+ temp = temp >> fmt->Rshift;
+ temp = temp << fmt->Rloss;
+ r = temp;
+
+ temp = pixel & fmt->Gmask;
+ temp = temp >> fmt->Gshift;
+ temp = temp << fmt->Gloss;
+ g = temp;
+
+ temp = pixel & fmt->Bmask;
+ temp = temp >> fmt->Bshift;
+ temp = temp << fmt->Bloss;
+ b = temp;
+
+ dst_pixels[i * 3 + 0] = r;
+ dst_pixels[i * 3 + 1] = g;
+ dst_pixels[i * 3 + 2] = b;
+ }
+ SDL_UnlockSurface(img);
+
+#if 1
+ // we will convert to sRGB in the shader
+ glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, img->w, img->h, 0, GL_RGB, GL_UNSIGNED_BYTE, dst_pixels);
+ check_error();
+#else
+ // implicit sRGB conversion in hardware
+ glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8, img->w, img->h, 0, GL_RGB, GL_UNSIGNED_BYTE, dst_pixels);
+ check_error();
+#endif
+ free(dst_pixels);
+ SDL_FreeSurface(img);
+}
+
+void write_ppm(const char *filename, unsigned char *screenbuf)
+{
+ FILE *fp = fopen(filename, "w");
+ fprintf(fp, "P6\n%d %d\n255\n", WIDTH, HEIGHT);
+ for (unsigned y = 0; y < HEIGHT; ++y) {
+ unsigned char *srcptr = screenbuf + ((HEIGHT - y - 1) * WIDTH) * 4;
+ for (unsigned x = 0; x < WIDTH; ++x) {
+ fputc(srcptr[x * 4 + 2], fp);
+ fputc(srcptr[x * 4 + 1], fp);
+ fputc(srcptr[x * 4 + 0], fp);
+ }
+ }
+ fclose(fp);
+}
+
+int main(int argc, char **argv)
+{
+ int quit = 0;
+
+ SDL_Init(SDL_INIT_EVERYTHING);
+ SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 0);
+ SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 0);
+ SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+ SDL_SetVideoMode(WIDTH, HEIGHT, 0, SDL_OPENGL);
+ SDL_WM_SetCaption("OpenGL window", NULL);
+
+ // geez
+ glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+ glPixelStorei(GL_PACK_ALIGNMENT, 1);
+
+ glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
+ check_error();
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ check_error();
+
+ load_texture("blg_wheels_woman_1.jpg");
+ //glGenerateMipmap(GL_TEXTURE_2D);
+ //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 4);
+ //check_error();
+
+ //load_texture("maserati_gts_wallpaper_1280x720_01.jpg");
+ //load_texture("90630d1295075297-console-games-wallpapers-wallpaper_need_for_speed_prostreet_09_1920x1080.jpg");
+ //load_texture("glacier-lake-1280-720-4087.jpg");
+
+#if 0
+ // sRGB reverse LUT
+ glBindTexture(GL_TEXTURE_1D, SRGB_REVERSE_LUT);
+ check_error();
+ glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+ check_error();
+ float srgb_reverse_tex[4096];
+ for (unsigned i = 0; i < 4096; ++i) {
+ float x = i / 4095.0;
+ if (x < 0.0031308f) {
+ srgb_reverse_tex[i] = 12.92f * x;
+ } else {
+ srgb_reverse_tex[i] = 1.055f * pow(x, 1.0f / 2.4f) - 0.055f;
+ }
+ }
+ glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE16F_ARB, 4096, 0, GL_LUMINANCE, GL_FLOAT, srgb_reverse_tex);
+ check_error();
+
+ // sRGB LUT
+ glBindTexture(GL_TEXTURE_1D, SRGB_LUT);
+ check_error();
+ glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+ glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+ check_error();
+ float srgb_tex[256];
+ for (unsigned i = 0; i < 256; ++i) {
+ float x = i / 255.0;
+ if (x < 0.04045f) {
+ srgb_tex[i] = x * (1.0f / 12.92f);
+ } else {
+ srgb_tex[i] = pow((x + 0.055) * (1.0 / 1.055f), 2.4);
+ }
+ }
+ glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE16F_ARB, 256, 0, GL_LUMINANCE, GL_FLOAT, srgb_tex);
+ check_error();
+#endif
+
+ // generate a PDO to hold the data we read back with glReadPixels()
+ // (Intel/DRI goes into a slow path if we don't read to PDO)
+ glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 1);
+ glBufferData(GL_PIXEL_PACK_BUFFER_ARB, WIDTH * HEIGHT * 4, NULL, GL_STREAM_READ);
+
+ make_hsv_wheel_texture();
+ update_hsv();
+
+ int prog = glCreateProgram();
+ GLhandleARB vs_obj = read_shader("vs.glsl", GL_VERTEX_SHADER);
+ GLhandleARB fs_obj = read_shader("fs.glsl", GL_FRAGMENT_SHADER);
+ glAttachObjectARB(prog, vs_obj);
+ check_error();
+ glAttachObjectARB(prog, fs_obj);
+ check_error();
+ glLinkProgram(prog);
+ check_error();
+
+ GLchar info_log[4096];
+ GLsizei log_length = sizeof(info_log) - 1;
+ log_length = sizeof(info_log) - 1;
+ glGetProgramInfoLog(prog, log_length, &log_length, info_log);
+ info_log[log_length] = 0;
+ printf("link: %s\n", info_log);
+
+ struct timespec start, now;
+ int frame = 0, screenshot = 0;
+ clock_gettime(CLOCK_MONOTONIC, &start);
+
+ while (!quit) {
+ SDL_Event event;
+ while (SDL_PollEvent(&event)) {
+ if (event.type == SDL_QUIT) {
+ quit = 1;
+ } else if (event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_ESCAPE) {
+ quit = 1;
+ } else if (event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_F1) {
+ screenshot = 1;
+ } else if (event.type == SDL_MOUSEBUTTONDOWN && event.button.button == SDL_BUTTON_LEFT) {
+ mouse(event.button.x, event.button.y);
+ } else if (event.type == SDL_MOUSEMOTION && (event.motion.state & SDL_BUTTON(1))) {
+ mouse(event.motion.x, event.motion.y);
+ }
+ }
+
+ ++frame;
+
+ draw_picture_quad(prog, frame);
+
+ glReadPixels(0, 0, WIDTH, HEIGHT, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, BUFFER_OFFSET(0));
+ check_error();
+
+ draw_hsv_wheel(0.0f, lift_rad, lift_theta, lift_v);
+ draw_hsv_wheel(0.2f, gamma_rad, gamma_theta, gamma_v);
+ draw_hsv_wheel(0.4f, gain_rad, gain_theta, gain_v);
+ draw_saturation_bar(0.6f);
+
+ SDL_GL_SwapBuffers();
+ check_error();
+
+ unsigned char *screenbuf = (unsigned char *)glMapBuffer(GL_PIXEL_PACK_BUFFER_ARB, GL_READ_ONLY);
+ check_error();
+ if (screenshot) {
+ char filename[256];
+ sprintf(filename, "frame%05d.ppm", frame);
+ write_ppm(filename, screenbuf);
+ printf("Screenshot: %s\n", filename);
+ screenshot = 0;
+ }
+ glUnmapBuffer(GL_PIXEL_PACK_BUFFER_ARB);
+ check_error();
+
+#if 1
+ clock_gettime(CLOCK_MONOTONIC, &now);
+ double elapsed = now.tv_sec - start.tv_sec +
+ 1e-9 * (now.tv_nsec - start.tv_nsec);
+ printf("%d frames in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
+ frame, elapsed, frame / elapsed,
+ 1e3 * elapsed / frame);
+#endif
+ }
+ return 0;
+}
projects / movit / blobdiff