Initial implementation of experimental gamma ramp API.
diff --git a/src/gamma.c b/src/gamma.c
new file mode 100644
index 0000000..ff97d60
--- /dev/null
+++ b/src/gamma.c
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+//========================================================================
+// GLFW - An OpenGL framework
+// Platform: Any
+// API version: 3.0
+// WWW: http://www.glfw.org/
+//------------------------------------------------------------------------
+// Copyright (c) 2010 Camilla Berglund <elmindreda@elmindreda.org>
+//
+// This software is provided 'as-is', without any express or implied
+// warranty. In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+// claim that you wrote the original software. If you use this software
+// in a product, an acknowledgment in the product documentation would
+// be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not
+// be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source
+// distribution.
+//
+//========================================================================
+
+#include "internal.h"
+
+#include <math.h>
+#include <string.h>
+
+
+//////////////////////////////////////////////////////////////////////////
+////// GLFW public API //////
+//////////////////////////////////////////////////////////////////////////
+
+//========================================================================
+// Calculate the gamma ramp table from specified values
+//========================================================================
+
+GLFWAPI void glfwSetGammaFormula(float gamma, float blacklevel, float gain)
+{
+ int i, size = 256;
+ GLFWgammaramp ramp;
+
+ if (!_glfwInitialized)
+ {
+ _glfwSetError(GLFW_NOT_INITIALIZED);
+ return;
+ }
+
+ for (i = 0; i < size; i++)
+ {
+ float value = (float) i / ((float) (size - 1));
+
+ // Apply gamma
+ value = pow(value, gamma) * 65535.f + 0.5f;
+
+ // Apply gain
+ value = gain * (value - 32767.5f) + 32767.5f;
+
+ // Apply black-level
+ value += blacklevel * 65535.f;
+
+ // Clamp values
+ if (value < 0.f)
+ value = 0.f;
+ else if (value > 65535.f)
+ value = 65535.f;
+
+ // Set the gamma ramp values
+ ramp.red[i] = (unsigned short) value;
+ ramp.green[i] = (unsigned short) value;
+ ramp.blue[i] = (unsigned short) value;
+ }
+
+ glfwSetGammaRamp(&ramp);
+}
+
+
+//========================================================================
+// Return the currently set gamma ramp
+//========================================================================
+
+GLFWAPI void glfwGetGammaRamp(GLFWgammaramp* ramp)
+{
+ if (!_glfwInitialized)
+ {
+ _glfwSetError(GLFW_NOT_INITIALIZED);
+ return;
+ }
+
+ *ramp = _glfwLibrary.currentRamp;
+}
+
+
+//========================================================================
+// Make the specified gamma ramp current
+//========================================================================
+
+GLFWAPI void glfwSetGammaRamp(const GLFWgammaramp* ramp)
+{
+ if (!_glfwInitialized)
+ {
+ _glfwSetError(GLFW_NOT_INITIALIZED);
+ return;
+ }
+
+ _glfwPlatformSetGammaRamp(ramp);
+ _glfwLibrary.currentRamp = *ramp;
+}
+
