From 8e354c2259fb18a5881a640195bd654ffd77f697 Mon Sep 17 00:00:00 2001
From: Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
Date: Thu, 28 Nov 2019 15:51:08 +0100
Subject: [PATCH] EGL: Implement glfwSwapBufferWithDamage()

This is provided by the EGL_KHR_swap_buffers_with_damage extension.
---
 src/egl_context.c | 24 ++++++++++++++++++++++++
 src/egl_context.h |  4 ++++
 2 files changed, 28 insertions(+)

diff --git a/src/egl_context.c b/src/egl_context.c
index 6a33396f..91cfefe3 100644
--- a/src/egl_context.c
+++ b/src/egl_context.c
@@ -232,6 +232,23 @@ static void swapBuffersEGL(_GLFWwindow* window)
     eglSwapBuffers(_glfw.egl.display, window->context.egl.surface);
 }
 
+static void swapBuffersWithDamageEGL(_GLFWwindow* window, GLFWrect* rects, int n_rects)
+{
+    if (window != _glfwPlatformGetTls(&_glfw.contextSlot))
+    {
+        _glfwInputError(GLFW_PLATFORM_ERROR,
+                        "EGL: The context must be current on the calling thread when swapping buffers");
+        return;
+    }
+
+    if (eglSwapBuffersWithDamageKHR)
+        eglSwapBuffersWithDamageKHR(_glfw.egl.display,
+                                    window->context.egl.surface,
+                                    (EGLint*)rects, (EGLint)n_rects);
+    else
+        eglSwapBuffers(_glfw.egl.display, window->context.egl.surface);
+}
+
 static void swapIntervalEGL(int interval)
 {
     eglSwapInterval(_glfw.egl.display, interval);
@@ -425,6 +442,12 @@ GLFWbool _glfwInitEGL(void)
         extensionSupportedEGL("EGL_KHR_get_all_proc_addresses");
     _glfw.egl.KHR_context_flush_control =
         extensionSupportedEGL("EGL_KHR_context_flush_control");
+    _glfw.egl.KHR_swap_buffers_with_damage =
+        extensionSupportedEGL("EGL_KHR_swap_buffers_with_damage");
+
+    if (_glfw.egl.KHR_swap_buffers_with_damage)
+        _glfw.egl.SwapBuffersWithDamageKHR = (PFN_eglSwapBuffersWithDamageKHR)
+            _glfw.egl.GetProcAddress("eglSwapBuffersWithDamageKHR");
 
     return GLFW_TRUE;
 }
@@ -694,6 +717,7 @@ GLFWbool _glfwCreateContextEGL(_GLFWwindow* window,
 
     window->context.makeCurrent = makeContextCurrentEGL;
     window->context.swapBuffers = swapBuffersEGL;
+    window->context.swapBuffersWithDamage = swapBuffersWithDamageEGL;
     window->context.swapInterval = swapIntervalEGL;
     window->context.extensionSupported = extensionSupportedEGL;
     window->context.getProcAddress = getProcAddressEGL;
diff --git a/src/egl_context.h b/src/egl_context.h
index 8bfb7db6..5c78ab27 100644
--- a/src/egl_context.h
+++ b/src/egl_context.h
@@ -132,6 +132,7 @@ typedef EGLBoolean (EGLAPIENTRY * PFN_eglSwapBuffers)(EGLDisplay,EGLSurface);
 typedef EGLBoolean (EGLAPIENTRY * PFN_eglSwapInterval)(EGLDisplay,EGLint);
 typedef const char* (EGLAPIENTRY * PFN_eglQueryString)(EGLDisplay,EGLint);
 typedef GLFWglproc (EGLAPIENTRY * PFN_eglGetProcAddress)(const char*);
+typedef EGLBoolean (EGLAPIENTRY * PFN_eglSwapBuffersWithDamageKHR)(EGLDisplay,EGLSurface,EGLint*,EGLint);
 #define eglGetConfigAttrib _glfw.egl.GetConfigAttrib
 #define eglGetConfigs _glfw.egl.GetConfigs
 #define eglGetDisplay _glfw.egl.GetDisplay
@@ -148,6 +149,7 @@ typedef GLFWglproc (EGLAPIENTRY * PFN_eglGetProcAddress)(const char*);
 #define eglSwapInterval _glfw.egl.SwapInterval
 #define eglQueryString _glfw.egl.QueryString
 #define eglGetProcAddress _glfw.egl.GetProcAddress
+#define eglSwapBuffersWithDamageKHR _glfw.egl.SwapBuffersWithDamageKHR
 
 #define _GLFW_EGL_CONTEXT_STATE            _GLFWcontextEGL egl
 #define _GLFW_EGL_LIBRARY_CONTEXT_STATE    _GLFWlibraryEGL egl
@@ -178,6 +180,7 @@ typedef struct _GLFWlibraryEGL
     GLFWbool        KHR_gl_colorspace;
     GLFWbool        KHR_get_all_proc_addresses;
     GLFWbool        KHR_context_flush_control;
+    GLFWbool        KHR_swap_buffers_with_damage;
 
     void*           handle;
 
@@ -197,6 +200,7 @@ typedef struct _GLFWlibraryEGL
     PFN_eglSwapInterval         SwapInterval;
     PFN_eglQueryString          QueryString;
     PFN_eglGetProcAddress       GetProcAddress;
+    PFN_eglSwapBuffersWithDamageKHR SwapBuffersWithDamageKHR;
 
 } _GLFWlibraryEGL;