Made gamma ramp functions per-monitor.

include/GL/glfw3.h

@@ -883,27 +883,28 @@ GLFWAPI const GLFWvidmode* glfwGetVideoModes(GLFWmonitor* monitor, int* count);
  */
 GLFWAPI GLFWvidmode glfwGetVideoMode(GLFWmonitor* monitor);
 
-/*! @brief Sets the system gamma ramp for all connected monitors to one
+/*! @brief Generates a gamma ramp and sets it for the specified monitor.
- *  generated from the specified exponent.
+ *  @param[in] monitor The monitor whose gamma ramp to set.
  *  @param[in] gamma The desired exponent.
  *  @ingroup gamma
  *
- *  @remarks This is a helper function layered on top of @ref glfwSetGammaRamp.
+ *  @remarks This is a helper function on top of @ref glfwSetGammaRamp.
  */
-GLFWAPI void glfwSetGamma(float gamma);
+GLFWAPI void glfwSetGamma(GLFWmonitor* monitor, float gamma);
 
-/*! @brief Retrieves the current system gamma ramp.
+/*! @brief Retrieves the current gamma ramp for the specified monitor.
+ *  @param[in] monitor The monitor to query.
  *  @param[out] ramp Where to store the gamma ramp.
  *  @ingroup gamma
  */
-GLFWAPI void glfwGetGammaRamp(GLFWgammaramp* ramp);
+GLFWAPI void glfwGetGammaRamp(GLFWmonitor* monitor, GLFWgammaramp* ramp);
 
-/*! @brief Sets the system gamma ramp for all connected monitors to the one
+/*! @brief Sets the gamma ramp for the specified monitor.
- *  specified.
+ *  @param[in] monitor The monitor whose gamma ramp to set.
  *  @param[in] ramp The gamma ramp to use.
  *  @ingroup gamma
  */
-GLFWAPI void glfwSetGammaRamp(const GLFWgammaramp* ramp);
+GLFWAPI void glfwSetGammaRamp(GLFWmonitor* monitor, const GLFWgammaramp* ramp);
 
 /*! @brief Resets all window hints to their default values
  *

src/cocoa_gamma.c

@@ -39,19 +39,27 @@
 //////                       GLFW platform API                      //////
 //////////////////////////////////////////////////////////////////////////
 
-void _glfwPlatformGetGammaRamp(GLFWgammaramp* ramp)
+void _glfwPlatformGetGammaRamp(_GLFWmonitor* monitor, GLFWgammaramp* ramp)
 {
+    // TODO: Support ramp sizes other than 256
+
     uint32_t sampleCount;
     int i;
     CGGammaValue red[GLFW_GAMMA_RAMP_SIZE];
     CGGammaValue green[GLFW_GAMMA_RAMP_SIZE];
     CGGammaValue blue[GLFW_GAMMA_RAMP_SIZE];
 
-    // For now, don't support anything that is not GLFW_GAMMA_RAMP_SIZE
+    if (CGDisplayGammaTableCapacity(monitor->ns.displayID) !=
-    if (_glfw.originalRampSize != GLFW_GAMMA_RAMP_SIZE)
+        GLFW_GAMMA_RAMP_SIZE)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "Cocoa: Only gamma ramps of size 256 supported");
         return;
+    }
 
-    CGGetDisplayTransferByTable(CGMainDisplayID(), GLFW_GAMMA_RAMP_SIZE, red, green, blue,
+    CGGetDisplayTransferByTable(monitor->ns.displayID,
+                                GLFW_GAMMA_RAMP_SIZE,
+                                red, green, blue,
                                 &sampleCount);
 
     for (i = 0; i < GLFW_GAMMA_RAMP_SIZE; i++)
@@ -62,17 +70,23 @@ void _glfwPlatformGetGammaRamp(GLFWgammaramp* ramp)
     }
 }
 
-void _glfwPlatformSetGammaRamp(const GLFWgammaramp* ramp)
+void _glfwPlatformSetGammaRamp(_GLFWmonitor* monitor, const GLFWgammaramp* ramp)
 {
+    // TODO: Support ramp sizes other than 256
+
     int i;
     int size = GLFW_GAMMA_RAMP_SIZE;
     CGGammaValue red[GLFW_GAMMA_RAMP_SIZE];
     CGGammaValue green[GLFW_GAMMA_RAMP_SIZE];
     CGGammaValue blue[GLFW_GAMMA_RAMP_SIZE];
 
-    // For now, don't support anything that is not GLFW_GAMMA_RAMP_SIZE
+    if (CGDisplayGammaTableCapacity(monitor->ns.displayID) !=
-    if (_glfw.originalRampSize != GLFW_GAMMA_RAMP_SIZE)
+        GLFW_GAMMA_RAMP_SIZE)
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "Cocoa: Only gamma ramps of size 256 supported");
         return;
+    }
 
     // Convert to float & take the difference of the original gamma and
     // the linear function.
@@ -83,6 +97,8 @@ void _glfwPlatformSetGammaRamp(const GLFWgammaramp* ramp)
         blue[i] = ramp->blue[i] / 65535.f;
     }
 
-    CGSetDisplayTransferByTable(CGMainDisplayID(), GLFW_GAMMA_RAMP_SIZE, red, green, blue);
+    CGSetDisplayTransferByTable(monitor->ns.displayID,
+                                GLFW_GAMMA_RAMP_SIZE,
+                                red, green, blue);
 }
 

src/cocoa_init.m

@@ -93,10 +93,6 @@ int _glfwPlatformInit(void)
     changeToResourcesDirectory();
 #endif
 
-    // Save the original gamma ramp
-    _glfw.originalRampSize = CGDisplayGammaTableCapacity(CGMainDisplayID());
-    _glfwPlatformGetGammaRamp(&_glfw.originalRamp);
-
     _glfwInitTimer();
 
     _glfwInitJoysticks();
@@ -123,10 +119,6 @@ void _glfwPlatformTerminate(void)
         _glfw.ns.eventSource = NULL;
     }
 
-    // Restore the original gamma ramp
-    if (_glfw.rampChanged)
-        _glfwPlatformSetGammaRamp(&_glfw.originalRamp);
-
     [NSApp setDelegate:nil];
     [_glfw.ns.delegate release];
     _glfw.ns.delegate = nil;

src/gamma.c

@@ -37,7 +37,7 @@
 //////                        GLFW public API                       //////
 //////////////////////////////////////////////////////////////////////////
 
-GLFWAPI void glfwSetGamma(float gamma)
+GLFWAPI void glfwSetGamma(GLFWmonitor* handle, float gamma)
 {
     int i, size = GLFW_GAMMA_RAMP_SIZE;
     GLFWgammaramp ramp;
@@ -75,29 +75,38 @@ GLFWAPI void glfwSetGamma(float gamma)
         ramp.blue[i]  = (unsigned short) value;
     }
 
-    glfwSetGammaRamp(&ramp);
+    glfwSetGammaRamp(handle, &ramp);
 }
 
-GLFWAPI void glfwGetGammaRamp(GLFWgammaramp* ramp)
+GLFWAPI void glfwGetGammaRamp(GLFWmonitor* handle, GLFWgammaramp* ramp)
 {
+    _GLFWmonitor* monitor = (_GLFWmonitor*) handle;
+
     if (!_glfwInitialized)
     {
         _glfwInputError(GLFW_NOT_INITIALIZED, NULL);
         return;
     }
 
-    _glfwPlatformGetGammaRamp(ramp);
+    _glfwPlatformGetGammaRamp(monitor, ramp);
 }
 
-GLFWAPI void glfwSetGammaRamp(const GLFWgammaramp* ramp)
+GLFWAPI void glfwSetGammaRamp(GLFWmonitor* handle, const GLFWgammaramp* ramp)
 {
+    _GLFWmonitor* monitor = (_GLFWmonitor*) handle;
+
     if (!_glfwInitialized)
     {
         _glfwInputError(GLFW_NOT_INITIALIZED, NULL);
         return;
     }
 
-    _glfwPlatformSetGammaRamp(ramp);
+    if (!monitor->rampChanged)
-    _glfw.rampChanged = GL_TRUE;
+    {
+        _glfwPlatformGetGammaRamp(monitor, &monitor->originalRamp);
+        monitor->rampChanged = GL_TRUE;
+    }
+
+    _glfwPlatformSetGammaRamp(monitor, ramp);
 }
 

src/init.c

@@ -150,6 +150,8 @@ GLFWAPI int glfwInit(void)
 
 GLFWAPI void glfwTerminate(void)
 {
+    int i;
+
     if (!_glfwInitialized)
         return;
 
@@ -157,6 +159,13 @@ GLFWAPI void glfwTerminate(void)
     while (_glfw.windowListHead)
         glfwDestroyWindow((GLFWwindow*) _glfw.windowListHead);
 
+    for (i = 0;  i < _glfw.monitorCount;  i++)
+    {
+        _GLFWmonitor* monitor = _glfw.monitors[i];
+        if (monitor->rampChanged)
+            _glfwPlatformSetGammaRamp(monitor, &monitor->originalRamp);
+    }
+
     _glfwDestroyMonitors();
 
     _glfwPlatformTerminate();

src/internal.h

@@ -267,6 +267,9 @@ struct _GLFWmonitor
     GLFWvidmode*    modes;
     int             modeCount;
 
+    GLFWgammaramp   originalRamp;
+    GLboolean       rampChanged;
+
     // This is defined in the window API's platform.h
     _GLFW_PLATFORM_MONITOR_STATE;
 };
@@ -285,10 +288,6 @@ struct _GLFWlibrary
     int             monitorCount;
     GLFWmonitorfun  monitorCallback;
 
-    GLFWgammaramp   originalRamp;
-    int             originalRampSize;
-    GLboolean       rampChanged;
-
     // This is defined in the window API's platform.h
     _GLFW_PLATFORM_LIBRARY_WINDOW_STATE;
     // This is defined in the context API's platform.h
@@ -376,17 +375,19 @@ GLFWvidmode* _glfwPlatformGetVideoModes(_GLFWmonitor* monitor, int* count);
  */
 void _glfwPlatformGetVideoMode(_GLFWmonitor* monitor, GLFWvidmode* mode);
 
-/*! @brief Returns the current system gamma ramp.
+/*! @brief Retrieves the current gamma ramp for the specified monitor.
+ *  @param[in] monitor The monitor to query.
  *  @param[out] ramp The current system gamma ramp.
  *  @ingroup platform
  */
-void _glfwPlatformGetGammaRamp(GLFWgammaramp* ramp);
+void _glfwPlatformGetGammaRamp(_GLFWmonitor* monitor, GLFWgammaramp* ramp);
 
-/*! @brief Sets the system gamma ramp.
+/*! @brief Sets the gamma ramp for the specified monitor.
+ *  @param[in] monitor The monitor whose gamma ramp to set.
  *  @param[in] ramp The desired system gamma ramp.
  *  @ingroup platform
  */
-void _glfwPlatformSetGammaRamp(const GLFWgammaramp* ramp);
+void _glfwPlatformSetGammaRamp(_GLFWmonitor* monitor, const GLFWgammaramp* ramp);
 
 /*! @brief Sets the system clipboard to the specified string.
  *  @param[in] window The window who will own the system clipboard contents, on

src/win32_gamma.c

@@ -36,13 +36,31 @@
 //////                       GLFW platform API                      //////
 //////////////////////////////////////////////////////////////////////////
 
-void _glfwPlatformGetGammaRamp(GLFWgammaramp* ramp)
+void _glfwPlatformGetGammaRamp(_GLFWmonitor* monitor, GLFWgammaramp* ramp)
 {
-    GetDeviceGammaRamp(GetDC(GetDesktopWindow()), (WORD*) ramp);
+    HDC dc;
+    DISPLAY_DEVICE display;
+
+    ZeroMemory(&display, sizeof(DISPLAY_DEVICE));
+    display.cb = sizeof(DISPLAY_DEVICE);
+    EnumDisplayDevices(monitor->win32.name, 0, &display, 0);
+
+    dc = CreateDC(L"DISPLAY", display.DeviceString, NULL, NULL);
+    GetDeviceGammaRamp(dc, (WORD*) ramp);
+    DeleteDC(dc);
 }
 
-void _glfwPlatformSetGammaRamp(const GLFWgammaramp* ramp)
+void _glfwPlatformSetGammaRamp(_GLFWmonitor* monitor, const GLFWgammaramp* ramp)
 {
-    SetDeviceGammaRamp(GetDC(GetDesktopWindow()), (WORD*) ramp);
+    HDC dc;
+    DISPLAY_DEVICE display;
+
+    ZeroMemory(&display, sizeof(DISPLAY_DEVICE));
+    display.cb = sizeof(DISPLAY_DEVICE);
+    EnumDisplayDevices(monitor->win32.name, 0, &display, 0);
+
+    dc = CreateDC(L"DISPLAY", display.DeviceString, NULL, NULL);
+    SetDeviceGammaRamp(dc, (WORD*) ramp);
+    DeleteDC(dc);
 }
 

src/win32_init.c

@@ -168,10 +168,6 @@ int _glfwPlatformInit(void)
     _control87(MCW_EM, MCW_EM);
 #endif
 
-    // Save the original gamma ramp
-    _glfw.originalRampSize = 256;
-    _glfwPlatformGetGammaRamp(&_glfw.originalRamp);
-
     if (!_glfwInitContextAPI())
         return GL_FALSE;
 
@@ -184,10 +180,6 @@ int _glfwPlatformInit(void)
 
 void _glfwPlatformTerminate(void)
 {
-    // Restore the original gamma ramp
-    if (_glfw.rampChanged)
-        _glfwPlatformSetGammaRamp(&_glfw.originalRamp);
-
     if (_glfw.win32.classAtom)
     {
         UnregisterClass(_GLFW_WNDCLASSNAME, GetModuleHandle(NULL));

src/x11_gamma.c

@@ -37,7 +37,7 @@
 //////                       GLFW internal API                      //////
 //////////////////////////////////////////////////////////////////////////
 
-// Detect gamma ramp support and save original gamma ramp, if available
+// Detect gamma ramp support
 //
 void _glfwInitGammaRamp(void)
 {
@@ -54,9 +54,7 @@ void _glfwInitGammaRamp(void)
         XRRScreenResources* rr = XRRGetScreenResources(_glfw.x11.display,
                                                        _glfw.x11.root);
 
-        _glfw.originalRampSize = XRRGetCrtcGammaSize(_glfw.x11.display,
+        if (XRRGetCrtcGammaSize(_glfw.x11.display, rr->crtcs[0]))
-                                                     rr->crtcs[0]);
-        if (_glfw.originalRampSize == 0)
         {
             // This is probably older Nvidia RandR with broken gamma support
             // Flag it as useless and try Xf86VidMode below, if available
@@ -65,28 +63,6 @@ void _glfwInitGammaRamp(void)
 
         XRRFreeScreenResources(rr);
     }
-
-    if (_glfw.x11.vidmode.available && !_glfw.originalRampSize)
-    {
-        // Get the gamma size using XF86VidMode
-        XF86VidModeGetGammaRampSize(_glfw.x11.display,
-                                    _glfw.x11.screen,
-                                    &_glfw.originalRampSize);
-    }
-
-    if (_glfw.originalRampSize)
-    {
-        // Save the original gamma ramp
-        _glfwPlatformGetGammaRamp(&_glfw.originalRamp);
-    }
-}
-
-// Restore original gamma ramp if necessary
-//
-void _glfwTerminateGammaRamp(void)
-{
-    if (_glfw.originalRampSize && _glfw.rampChanged)
-        _glfwPlatformSetGammaRamp(&_glfw.originalRamp);
 }
 
 
@@ -94,83 +70,85 @@ void _glfwTerminateGammaRamp(void)
 //////                       GLFW platform API                      //////
 //////////////////////////////////////////////////////////////////////////
 
-void _glfwPlatformGetGammaRamp(GLFWgammaramp* ramp)
+void _glfwPlatformGetGammaRamp(_GLFWmonitor* monitor, GLFWgammaramp* ramp)
 {
-    // For now, don't support anything that is not GLFW_GAMMA_RAMP_SIZE
+    // TODO: Support ramp sizes other than 256
-    if (_glfw.originalRampSize != GLFW_GAMMA_RAMP_SIZE)
-    {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
-                        "X11: Failed to get gamma ramp due to size "
-                        "incompatibility");
-        return;
-    }
 
     if (_glfw.x11.randr.available && !_glfw.x11.randr.gammaBroken)
     {
+        XRRCrtcGamma* gamma;
         size_t size = GLFW_GAMMA_RAMP_SIZE * sizeof(unsigned short);
 
-        XRRScreenResources* rr = XRRGetScreenResources(_glfw.x11.display,
+        if (XRRGetCrtcGammaSize(_glfw.x11.display, monitor->x11.crtc) !=
-                                                       _glfw.x11.root);
+            GLFW_GAMMA_RAMP_SIZE)
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "X11: Only gamma ramps of size 256 supported");
+            return;
+        }
 
-        XRRCrtcGamma* gamma = XRRGetCrtcGamma(_glfw.x11.display,
+        gamma = XRRGetCrtcGamma(_glfw.x11.display, monitor->x11.crtc);
-                                              rr->crtcs[0]);
-
-        // TODO: Handle case of original ramp size having a size other than 256
 
         memcpy(ramp->red, gamma->red, size);
         memcpy(ramp->green, gamma->green, size);
         memcpy(ramp->blue, gamma->blue, size);
 
         XRRFreeGamma(gamma);
-        XRRFreeScreenResources(rr);
     }
     else if (_glfw.x11.vidmode.available)
     {
+        int size;
+        XF86VidModeGetGammaRampSize(_glfw.x11.display, _glfw.x11.screen, &size);
+
+        if (size != GLFW_GAMMA_RAMP_SIZE)
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "X11: Only gamma ramps of size 256 supported");
+            return;
+        }
+
         XF86VidModeGetGammaRamp(_glfw.x11.display,
                                 _glfw.x11.screen,
                                 GLFW_GAMMA_RAMP_SIZE,
-                                ramp->red,
+                                ramp->red, ramp->green, ramp->blue);
-                                ramp->green,
-                                ramp->blue);
     }
 }
 
-void _glfwPlatformSetGammaRamp(const GLFWgammaramp* ramp)
+void _glfwPlatformSetGammaRamp(_GLFWmonitor* monitor, const GLFWgammaramp* ramp)
 {
-    // For now, don't support anything that is not GLFW_GAMMA_RAMP_SIZE
-    if (_glfw.originalRampSize != GLFW_GAMMA_RAMP_SIZE)
-    {
-        _glfwInputError(GLFW_PLATFORM_ERROR,
-                        "X11: Failed to set gamma ramp due to size "
-                        "incompatibility");
-        return;
-    }
-
     if (_glfw.x11.randr.available && !_glfw.x11.randr.gammaBroken)
     {
-        int i;
         size_t size = GLFW_GAMMA_RAMP_SIZE * sizeof(unsigned short);
+        XRRCrtcGamma* gamma;
 
-        XRRScreenResources* rr = XRRGetScreenResources(_glfw.x11.display,
+        if (XRRGetCrtcGammaSize(_glfw.x11.display, monitor->x11.crtc) !=
-                                                       _glfw.x11.root);
+            GLFW_GAMMA_RAMP_SIZE)
-
-        // Update gamma per monitor
-        for (i = 0;  i < rr->ncrtc;  i++)
         {
-            XRRCrtcGamma* gamma = XRRAllocGamma(GLFW_GAMMA_RAMP_SIZE);
+            _glfwInputError(GLFW_PLATFORM_ERROR,
-
+                            "X11: Only gamma ramps of size 256 supported");
-            memcpy(gamma->red, ramp->red, size);
+            return;
-            memcpy(gamma->green, ramp->green, size);
-            memcpy(gamma->blue, ramp->blue, size);
-
-            XRRSetCrtcGamma(_glfw.x11.display, rr->crtcs[i], gamma);
-            XRRFreeGamma(gamma);
         }
 
-        XRRFreeScreenResources(rr);
+        gamma = XRRAllocGamma(GLFW_GAMMA_RAMP_SIZE);
+
+        memcpy(gamma->red, ramp->red, size);
+        memcpy(gamma->green, ramp->green, size);
+        memcpy(gamma->blue, ramp->blue, size);
+
+        XRRSetCrtcGamma(_glfw.x11.display, monitor->x11.crtc, gamma);
     }
     else if (_glfw.x11.vidmode.available)
     {
+        int size;
+        XF86VidModeGetGammaRampSize(_glfw.x11.display, _glfw.x11.screen, &size);
+
+        if (size != GLFW_GAMMA_RAMP_SIZE)
+        {
+            _glfwInputError(GLFW_PLATFORM_ERROR,
+                            "X11: Only gamma ramps of size 256 supported");
+            return;
+        }
+
         XF86VidModeSetGammaRamp(_glfw.x11.display,
                                 _glfw.x11.screen,
                                 GLFW_GAMMA_RAMP_SIZE,

src/x11_init.c

@@ -603,8 +603,6 @@ void _glfwPlatformTerminate(void)
         _glfw.x11.cursor = (Cursor) 0;
     }
 
-    _glfwTerminateGammaRamp();
-
     _glfwTerminateJoysticks();
 
     _glfwTerminateContextAPI();

src/x11_platform.h

@@ -210,7 +210,6 @@ void _glfwInitTimer(void);
 
 // Gamma
 void _glfwInitGammaRamp(void);
-void _glfwTerminateGammaRamp(void);
 
 // OpenGL support
 int _glfwInitContextAPI(void);

tests/gamma.c

@@ -49,7 +49,7 @@ static void set_gamma(float value)
 {
     gamma_value = value;
     printf("Gamma: %f\n", gamma_value);
-    glfwSetGamma(gamma_value);
+    glfwSetGamma(glfwGetPrimaryMonitor(), gamma_value);
 }
 
 static void error_callback(int error, const char* description)