From 7204186779e096ceab7b39f54dcf6f606062f29b Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Mon, 30 Sep 2013 21:39:32 +0200
Subject: [PATCH] add egl3test

---
 .gitignore     |  1 +
 Makefile       |  3 +++
 eglbackend.cpp | 27 ++++++++++++++++++++++-----
 eglbackend.h   |  3 +++
 glxbackend.cpp |  2 +-
 5 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/.gitignore b/.gitignore
index 8c21785..8539231 100644
--- a/.gitignore
+++ b/.gitignore
@@ -3,5 +3,6 @@ glx2test
 egltest
 egl2test
 glx3test
+egl3test
 gles2test
 eglinfo
diff --git a/Makefile b/Makefile
index 2fa9312..a6df6dc 100644
--- a/Makefile
+++ b/Makefile
@@ -28,6 +28,9 @@ egl2test: $(COMMON_SRC) $(COMMON_HDR) glutil_gl2.cpp eglbackend.cpp eglbackend.h
 glx3test: $(COMMON_SRC) $(COMMON_HDR) glutil_gl2.cpp glxbackend.cpp glxbackend.h
 	g++ $(CFLAGS) -DWIN_GLX -DCON_GL3 $^ -lGL $(COMMON_LD) -o $@
 
+egl3test: $(COMMON_SRC) $(COMMON_HDR) glutil_gl2.cpp eglbackend.cpp eglbackend.h
+	g++ $(CFLAGS) -DWIN_EGL -DCON_GL3 $^ -lEGL -lGL $(COMMON_LD) -o $@
+
 gles2test: $(COMMON_SRC) $(COMMON_HDR) glutil_gl2.cpp eglbackend.cpp eglbackend.h
 	g++ $(CFLAGS) -DWIN_EGL -DCON_GLES2 $^ -lEGL -lGLESv2 $(COMMON_LD) -o $@
 
diff --git a/eglbackend.cpp b/eglbackend.cpp
index 2717b86..47e0384 100644
--- a/eglbackend.cpp
+++ b/eglbackend.cpp
@@ -24,8 +24,8 @@
 
 #include <EGL/eglext.h>
 
-#if !defined(CON_GL1) && !defined(CON_GLES2)
-#error "Valid GL contexts for EGL are: GL1, GLES2"
+#if !defined(CON_GL1) && !defined(CON_GL3) && !defined(CON_GLES2)
+#error "Valid GL contexts for EGL are: GL1, GL3, GLES2"
 #endif
 
 static const char *eglErrorToString(EGLint e)
@@ -66,6 +66,10 @@ static const EGLint configAttribs[] = {
 static const EGLint contextAttribs[] = {
 #ifdef CON_GLES2
 	EGL_CONTEXT_CLIENT_VERSION, 2,
+#elif CON_GL3
+	EGL_CONTEXT_MAJOR_VERSION_KHR, 3,
+	EGL_CONTEXT_MINOR_VERSION_KHR, 0,
+	EGL_CONTEXT_FLAGS_KHR, EGL_CONTEXT_OPENGL_FORWARD_COMPATIBLE_BIT_KHR,
 #endif
 	EGL_NONE
 };
@@ -81,9 +85,9 @@ VisualID EGLBackend::initialize(Display *xDisplay)
 		if (eglInitialize(display, &eglMajor, &eglMinor) == EGL_FALSE)
 			dieEgl("Failed to initialize EGL");
 		printf("Using EGL version: %d.%d\n", eglMajor, eglMinor);
-		if (eglMajor == 1 && eglMinor < 3) {
-			// Choosing the GL context version requires EGL 1.3
-			die("Need at least EGL 1.3 to function properly\n");
+		if (eglMajor == 1 && eglMinor < 4) {
+			// Choosing the GL context version requires EGL 1.3, creating an OpenGL 3 context requires EGL 1.4
+			die("Need at least EGL 1.4 to function properly\n");
 		}
 #ifdef CON_GLES2
 		if (eglBindAPI(EGL_OPENGL_ES_API) == EGL_FALSE)
@@ -91,6 +95,12 @@ VisualID EGLBackend::initialize(Display *xDisplay)
 		if (eglBindAPI(EGL_OPENGL_API) == EGL_FALSE)
 #endif
 			dieEgl("Failed to bind API");
+		// check for the extension we need
+#ifdef CON_GL3
+		if (!haveEGLExtension("EGL_KHR_create_context")) {
+			die("Required EGL extension EGL_KHR_create_context is not supported\n");
+		}
+#endif
 		// get an appropriate config
 		EGLConfig configs[1];
 		EGLint count;
@@ -108,6 +118,13 @@ VisualID EGLBackend::initialize(Display *xDisplay)
 	return (VisualID)val;
 }
 
+bool EGLBackend::haveEGLExtension(const std::string &name)
+{
+	assert(display != EGL_NO_DISPLAY);
+	std::string extensions = eglQueryString(display, EGL_EXTENSIONS);
+	return (std::string(" "+extensions+" ").find(" "+name+" ") != std::string::npos);
+}
+
 void EGLBackend::createContext(Window window)
 {
 	assert(display != EGL_NO_DISPLAY && context == EGL_NO_CONTEXT);
diff --git a/eglbackend.h b/eglbackend.h
index acd8b67..918f6f9 100644
--- a/eglbackend.h
+++ b/eglbackend.h
@@ -19,6 +19,7 @@
 #include "glwindow.h"
 
 #include <EGL/egl.h>
+#include <string>
 
 
 /** Make an X window fit for GL. You have to manage the X window yourself! */
@@ -45,4 +46,6 @@ private:
 	EGLConfig  config;
 	EGLSurface surface;
 	EGLContext context;
+	
+	bool haveEGLExtension(const std::string &name);
 };
diff --git a/glxbackend.cpp b/glxbackend.cpp
index 2023954..f556a64 100644
--- a/glxbackend.cpp
+++ b/glxbackend.cpp
@@ -58,7 +58,7 @@ VisualID GLXBackend::initialize(Display *display)
 		int glxMajor, glxMinor;
 		glXQueryVersion(display, &glxMajor, &glxMinor);
 		printf("Using GLX version: %d.%d\n", glxMajor, glxMinor);
-		if (glxMajor < 1 || (glxMajor == 1 && glxMinor < 3)) {
+		if (glxMajor == 1 && glxMinor < 3) {
 			// glXChooseFBConfig and glXCreateNewContext require GLX 1.3
 			die("Need at least GLX 1.3 to function properly\n");
 		}
-- 
2.30.2