void Monitor::getNewGammaRamp()
{
const GLFWgammaramp* gr = glfwGetGammaRamp(monitor);
std::copy(gr->blue, gr->blue + gr->size, gammaRamp.blue.begin());
std::copy(gr->green, gr->green + gr->size, gammaRamp.green.begin());
std::copy(gr->red, gr->red + gr->size, gammaRamp.red.begin());
}
GLFWAPI void glfwSetGamma(GLFWmonitor* handle, float gamma)
{
unsigned int i;
unsigned short* values;
GLFWgammaramp ramp;
const GLFWgammaramp* original;
assert(handle != NULL);
assert(gamma > 0.f);
assert(gamma <= FLT_MAX);
_GLFW_REQUIRE_INIT();
if (gamma != gamma || gamma <= 0.f || gamma > FLT_MAX)
{
_glfwInputError(GLFW_INVALID_VALUE, "Invalid gamma value %f", gamma);
return;
}
original = glfwGetGammaRamp(handle);
if (!original)
return;
values = calloc(original->size, sizeof(unsigned short));
for (i = 0; i < original->size; i++)
{
float value;
// Calculate intensity
value = i / (float) (original->size - 1);
// Apply gamma curve
value = powf(value, 1.f / gamma) * 65535.f + 0.5f;
// Clamp to value range
value = _glfw_fminf(value, 65535.f);
values[i] = (unsigned short) value;
}
ramp.red = values;
ramp.green = values;
ramp.blue = values;
ramp.size = original->size;
glfwSetGammaRamp(handle, &ramp);
free(values);
}
int main(int argc, char** argv)
{
GLFWmonitor* monitor = NULL;
GLFWwindow* window;
GLFWgammaramp orig_ramp;
struct nk_context* nk;
struct nk_font_atlas* atlas;
float gamma_value = 1.f;
glfwSetErrorCallback(error_callback);
if (!glfwInit())
exit(EXIT_FAILURE);
monitor = glfwGetPrimaryMonitor();
window = glfwCreateWindow(800, 400, "Gamma Test", NULL, NULL);
if (!window)
{
glfwTerminate();
exit(EXIT_FAILURE);
}
{
const GLFWgammaramp* ramp = glfwGetGammaRamp(monitor);
const size_t array_size = ramp->size * sizeof(short);
orig_ramp.size = ramp->size;
orig_ramp.red = malloc(array_size);
orig_ramp.green = malloc(array_size);
orig_ramp.blue = malloc(array_size);
memcpy(orig_ramp.red, ramp->red, array_size);
memcpy(orig_ramp.green, ramp->green, array_size);
memcpy(orig_ramp.blue, ramp->blue, array_size);
}
glfwMakeContextCurrent(window);
gladLoadGLLoader((GLADloadproc) glfwGetProcAddress);
glfwSwapInterval(1);
nk = nk_glfw3_init(window, NK_GLFW3_INSTALL_CALLBACKS);
nk_glfw3_font_stash_begin(&atlas);
nk_glfw3_font_stash_end();
glfwSetKeyCallback(window, key_callback);
while (!glfwWindowShouldClose(window))
{
int width, height;
struct nk_rect area;
glfwGetWindowSize(window, &width, &height);
area = nk_rect(0.f, 0.f, (float) width, (float) height);
nk_window_set_bounds(nk, "", area);
glClear(GL_COLOR_BUFFER_BIT);
nk_glfw3_new_frame();
if (nk_begin(nk, "", area, 0))
{
const GLFWgammaramp* ramp;
nk_layout_row_dynamic(nk, 30, 3);
if (nk_slider_float(nk, 0.1f, &gamma_value, 5.f, 0.1f))
glfwSetGamma(monitor, gamma_value);
nk_labelf(nk, NK_TEXT_LEFT, "%0.1f", gamma_value);
if (nk_button_label(nk, "Revert"))
glfwSetGammaRamp(monitor, &orig_ramp);
ramp = glfwGetGammaRamp(monitor);
nk_layout_row_dynamic(nk, height - 60.f, 3);
chart_ramp_array(nk, nk_rgb(255, 0, 0), ramp->size, ramp->red);
chart_ramp_array(nk, nk_rgb(0, 255, 0), ramp->size, ramp->green);
chart_ramp_array(nk, nk_rgb(0, 0, 255), ramp->size, ramp->blue);
}
nk_end(nk);
nk_glfw3_render(NK_ANTI_ALIASING_ON);
glfwSwapBuffers(window);
glfwWaitEventsTimeout(1.0);
}
free(orig_ramp.red);
free(orig_ramp.green);
free(orig_ramp.blue);
nk_glfw3_shutdown();
glfwTerminate();
exit(EXIT_SUCCESS);
}
