Merge 0a898628ff into 3a60992a41

docs/window.dox

@@ -437,6 +437,18 @@ Context release behaviors are described in detail by the
 [GL_KHR_context_flush_control](https://www.opengl.org/registry/specs/KHR/context_flush_control.txt)
 extension.
 
+@anchor GLFW_CONTEXT_PRIORITY_hint
+__GLFW_CONTEXT_PRIORITY__ specifies the context priority to be used by the 
+context. Possible values are one of `GLFW_PRIORITY_LOW`, `GLFW_PRIORITY_MEDIUM`, 
+`GLFW_PRIORITY_HIGH` or `GLFW_PRIORITY_REALTIME`. This functionality is currently
+only implemented for the EGL context creating API.
+
+Context priorities are described in detail by the 
+[EGL_NV_context_priority_realtime](https://www.khronos.org/registry/EGL/extensions/NV/EGL_NV_context_priority_realtime.txt)
+and 
+[EGL_IMG_context_priority](https://www.khronos.org/registry/EGL/extensions/IMG/EGL_IMG_context_priority.txt)
+extensions.
+
 @anchor GLFW_CONTEXT_NO_ERROR_hint
 __GLFW_CONTEXT_NO_ERROR__ specifies whether errors should be generated by the
 context.  Possible values are `GLFW_TRUE` and `GLFW_FALSE`.  If enabled,
@@ -538,6 +550,7 @@ GLFW_CONTEXT_VERSION_MAJOR    | 1                           | Any valid major ve
 GLFW_CONTEXT_VERSION_MINOR    | 0                           | Any valid minor version number of the chosen client API
 GLFW_CONTEXT_ROBUSTNESS       | `GLFW_NO_ROBUSTNESS`        | `GLFW_NO_ROBUSTNESS`, `GLFW_NO_RESET_NOTIFICATION` or `GLFW_LOSE_CONTEXT_ON_RESET`
 GLFW_CONTEXT_RELEASE_BEHAVIOR | `GLFW_ANY_RELEASE_BEHAVIOR` | `GLFW_ANY_RELEASE_BEHAVIOR`, `GLFW_RELEASE_BEHAVIOR_FLUSH` or `GLFW_RELEASE_BEHAVIOR_NONE`
+GLFW_CONTEXT_PRIORITY         | `GLFW_PRIORITY_MEDIUM`      | `GLFW_PRIORITY_LOW`, `GLFW_PRIORITY_MEDIUM`, `GLFW_PRIORITY_HIGH`, `GLFW_PRIORITY_REALTIME`
 GLFW_OPENGL_FORWARD_COMPAT    | `GLFW_FALSE`                | `GLFW_TRUE` or `GLFW_FALSE`
 GLFW_CONTEXT_DEBUG            | `GLFW_FALSE`                | `GLFW_TRUE` or `GLFW_FALSE`
 GLFW_OPENGL_PROFILE           | `GLFW_OPENGL_ANY_PROFILE`   | `GLFW_OPENGL_ANY_PROFILE`, `GLFW_OPENGL_COMPAT_PROFILE` or `GLFW_OPENGL_CORE_PROFILE`

include/GLFW/glfw3.h

@@ -1084,6 +1084,11 @@ extern "C" {
  *  [window hint](@ref GLFW_SCALE_TO_MONITOR).
  */
 #define GLFW_SCALE_TO_MONITOR       0x0002200C
+/*! @brief Context priority.
+ *
+ *  Context priority hint [hint](@ref GLFW_CONTEXT_PRIORITY_hint).
+ */
+#define GLFW_CONTEXT_PRIORITY       0x0002200D
 /*! @brief macOS specific
  *  [window hint](@ref GLFW_COCOA_RETINA_FRAMEBUFFER_hint).
  */
@@ -1152,6 +1157,11 @@ extern "C" {
 #define GLFW_ANGLE_PLATFORM_TYPE_VULKAN  0x00037007
 #define GLFW_ANGLE_PLATFORM_TYPE_METAL   0x00037008
 
+#define GLFW_PRIORITY_LOW           0x00038001
+#define GLFW_PRIORITY_MEDIUM        0x00038002
+#define GLFW_PRIORITY_HIGH          0x00038003
+#define GLFW_PRIORITY_REALTIME      0x00038004
+
 /*! @defgroup shapes Standard cursor shapes
  *  @brief Standard system cursor shapes.
  *

src/context.c

@@ -170,6 +170,20 @@ GLFWbool _glfwIsValidContextConfig(const _GLFWctxconfig* ctxconfig)
         }
     }
 
+    if (ctxconfig->priority)
+    {
+        if (ctxconfig->priority != GLFW_PRIORITY_LOW &&
+            ctxconfig->priority != GLFW_PRIORITY_MEDIUM &&
+            ctxconfig->priority != GLFW_PRIORITY_HIGH &&
+            ctxconfig->priority != GLFW_PRIORITY_REALTIME)
+        {
+            _glfwInputError(GLFW_INVALID_ENUM,
+                            "Invalid context priority 0x%08X",
+                            ctxconfig->priority);
+            return GLFW_FALSE;
+        }
+    }
+
     return GLFW_TRUE;
 }
 

src/egl_context.c

@@ -485,6 +485,8 @@ GLFWbool _glfwInitEGL(void)
         extensionSupportedEGL("EGL_KHR_context_flush_control");
     _glfw.egl.EXT_present_opaque =
         extensionSupportedEGL("EGL_EXT_present_opaque");
+    _glfw.egl.IMG_context_priority =
+        extensionSupportedEGL("EGL_IMG_context_priority");
 
     return GLFW_TRUE;
 }
@@ -634,6 +636,24 @@ GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
         }
     }
 
+    if (_glfw.egl.IMG_context_priority && ctxconfig->priority != GLFW_PRIORITY_MEDIUM)
+    {
+        if (ctxconfig->priority == GLFW_PRIORITY_LOW)
+        {
+            SET_ATTRIB(EGL_CONTEXT_PRIORITY_LEVEL_IMG,
+                      EGL_CONTEXT_PRIORITY_LOW_IMG);
+        } else if (ctxconfig->priority == GLFW_PRIORITY_HIGH)
+        {
+            SET_ATTRIB(EGL_CONTEXT_PRIORITY_LEVEL_IMG,
+                      EGL_CONTEXT_PRIORITY_HIGH_IMG);
+        }
+        else if (ctxconfig->priority == GLFW_PRIORITY_REALTIME)
+        {
+            SET_ATTRIB(EGL_CONTEXT_PRIORITY_LEVEL_IMG,
+                      EGL_CONTEXT_PRIORITY_REALTIME_NV);
+        }
+    }
+
     SET_ATTRIB(EGL_NONE, EGL_NONE);
 
     window->context.egl.handle = eglCreateContext(_glfw.egl.display,

src/internal.h

@@ -187,6 +187,11 @@ typedef const GLubyte* (APIENTRY * PFNGLGETSTRINGIPROC)(GLenum,GLuint);
 #define EGL_PLATFORM_ANGLE_TYPE_VULKAN_ANGLE 0x3450
 #define EGL_PLATFORM_ANGLE_TYPE_METAL_ANGLE 0x3489
 #define EGL_PLATFORM_ANGLE_NATIVE_PLATFORM_TYPE_ANGLE 0x348f
+#define EGL_CONTEXT_PRIORITY_LEVEL_IMG 0x3100
+#define EGL_CONTEXT_PRIORITY_HIGH_IMG 0x3101
+#define EGL_CONTEXT_PRIORITY_MEDIUM_IMG 0x3102
+#define EGL_CONTEXT_PRIORITY_LOW_IMG 0x3103
+#define EGL_CONTEXT_PRIORITY_REALTIME_NV 0x3357
 
 typedef int EGLint;
 typedef unsigned int EGLBoolean;
@@ -444,6 +449,7 @@ struct _GLFWctxconfig
     int           profile;
     int           robustness;
     int           release;
+    int           priority;
     _GLFWwindow*  share;
     struct {
         GLFWbool  offline;
@@ -814,6 +820,7 @@ struct _GLFWlibrary
         GLFWbool        ANGLE_platform_angle_d3d;
         GLFWbool        ANGLE_platform_angle_vulkan;
         GLFWbool        ANGLE_platform_angle_metal;
+        GLFWbool        IMG_context_priority;
 
         void*           handle;
 

src/window.c

@@ -264,6 +264,7 @@ void glfwDefaultWindowHints(void)
     _glfw.hints.context.source = GLFW_NATIVE_CONTEXT_API;
     _glfw.hints.context.major  = 1;
     _glfw.hints.context.minor  = 0;
+    _glfw.hints.context.priority = GLFW_PRIORITY_MEDIUM;
 
     // The default is a focused, visible, resizable window with decorations
     memset(&_glfw.hints.window, 0, sizeof(_glfw.hints.window));
@@ -422,6 +423,9 @@ GLFWAPI void glfwWindowHint(int hint, int value)
         case GLFW_REFRESH_RATE:
             _glfw.hints.refreshRate = value;
             return;
+        case GLFW_CONTEXT_PRIORITY:
+            _glfw.hints.context.priority = value;
+            return;
     }
 
     _glfwInputError(GLFW_INVALID_ENUM, "Invalid window hint 0x%08X", hint);

tests/glfwinfo.c

@@ -71,6 +71,11 @@
 #define PLATFORM_NAME_X11   "x11"
 #define PLATFORM_NAME_NULL  "null"
 
+#define PRIORITY_LOW        "low"
+#define PRIORITY_MEDIUM     "medium"
+#define PRIORITY_HIGH       "high"
+#define PRIORITY_REALTIME   "realtime"
+
 static void usage(void)
 {
     printf("Usage: glfwinfo [OPTION]...\n");
@@ -133,6 +138,11 @@ static void usage(void)
                                         ANGLE_TYPE_METAL ")\n");
     printf("      --graphics-switching  request macOS graphics switching\n");
     printf("      --disable-xcb-surface disable VK_KHR_xcb_surface extension\n");
+    printf("      --priority=PRIORITY   request context priority to use ("
+                                        PRIORITY_LOW ","
+                                        PRIORITY_MEDIUM "," 
+                                        PRIORITY_HIGH "," 
+                                        PRIORITY_REALTIME ")\n");
 }
 
 static void error_callback(int error, const char* description)
@@ -361,6 +371,7 @@ int main(int argc, char** argv)
     int context_robustness = GLFW_NO_ROBUSTNESS;
     bool context_debug = false;
     bool context_no_error = false;
+    int context_priority = GLFW_PRIORITY_MEDIUM;
     bool opengl_forward = false;
     int opengl_profile = GLFW_OPENGL_ANY_PROFILE;
     int fb_red_bits = 8;
@@ -388,7 +399,7 @@ int main(int argc, char** argv)
            REDBITS, GREENBITS, BLUEBITS, ALPHABITS, DEPTHBITS, STENCILBITS,
            ACCUMREDBITS, ACCUMGREENBITS, ACCUMBLUEBITS, ACCUMALPHABITS,
            AUXBUFFERS, SAMPLES, STEREO, SRGB, SINGLEBUFFER, NOERROR_SRSLY,
-           ANGLE_TYPE, GRAPHICS_SWITCHING, XCB_SURFACE };
+           ANGLE_TYPE, GRAPHICS_SWITCHING, XCB_SURFACE, PRIORITY };
     const struct option options[] =
     {
         { "platform",           1, NULL, PLATFORM },
@@ -424,6 +435,7 @@ int main(int argc, char** argv)
         { "angle-type",         1, NULL, ANGLE_TYPE },
         { "graphics-switching", 0, NULL, GRAPHICS_SWITCHING },
         { "vk-xcb-surface",     0, NULL, XCB_SURFACE },
+        { "priority",           1, NULL, PRIORITY },
         { NULL, 0, NULL, 0 }
     };
 
@@ -652,6 +664,22 @@ int main(int argc, char** argv)
             case XCB_SURFACE:
                 disable_xcb_surface = true;
                 break;
+            case PRIORITY:
+                if (strcasecmp(optarg, PRIORITY_LOW) == 0)
+                    context_priority = GLFW_PRIORITY_LOW;
+                else if (strcasecmp(optarg, PRIORITY_MEDIUM) == 0)
+                    context_priority = GLFW_PRIORITY_MEDIUM;
+                else if (strcasecmp(optarg, PRIORITY_HIGH) == 0)
+                    context_priority = GLFW_PRIORITY_HIGH;
+                else if (strcasecmp(optarg, PRIORITY_REALTIME) == 0)
+                    context_priority = GLFW_PRIORITY_REALTIME;
+                else
+                {
+                    usage();
+                    exit(EXIT_FAILURE);
+                }
+                break;
+
             default:
                 usage();
                 exit(EXIT_FAILURE);
@@ -690,6 +718,7 @@ int main(int argc, char** argv)
     glfwWindowHint(GLFW_CONTEXT_NO_ERROR, context_no_error);
     glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, opengl_forward);
     glfwWindowHint(GLFW_OPENGL_PROFILE, opengl_profile);
+    glfwWindowHint(GLFW_CONTEXT_PRIORITY, context_priority);
 
     glfwWindowHint(GLFW_RED_BITS, fb_red_bits);
     glfwWindowHint(GLFW_BLUE_BITS, fb_blue_bits);