-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();
-}
-