From b4dc0596570275aa9def5ff63af951beb8473d58 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sun, 8 Sep 2013 21:29:26 +0200
Subject: [PATCH 1/1] rename window system and context choice variables

---
 Makefile       | 10 +++++++---
 eglbackend.cpp | 10 +++++++---
 gltest.cpp     |  6 +++---
 glutil.h       |  2 +-
 glutil_gl1.cpp |  6 +++++-
 glutil_gl2.cpp |  4 ++++
 glxbackend.cpp |  4 ++++
 7 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/Makefile b/Makefile
index 52a6495..c848639 100644
--- a/Makefile
+++ b/Makefile
@@ -7,14 +7,18 @@ BINARIES := glxtest egltest glestest eglinfo
 
 all: $(BINARIES)
 
+# choices (not all combinations are valid)
+# windowing system WIN_{GLX,EGL}
+# the kind of context CON_{GL1,GLES2}
+
 glxtest: $(COMMON_SRC) $(COMMON_HDR) glutil_gl1.cpp glxbackend.cpp glxbackend.h
-	g++ $(FLAGS) -DUSE_GLX $(COMMON_SRC) glutil_gl1.cpp glxbackend.cpp -lGL -lX11 -lboost_program_options -o glxtest
+	g++ $(FLAGS) -DWIN_GLX -DCON_GL1 $(COMMON_SRC) glutil_gl1.cpp glxbackend.cpp -lGL -lX11 -lboost_program_options -o glxtest
 
 egltest: $(COMMON_SRC) $(COMMON_HDR) glutil_gl1.cpp eglbackend.cpp eglbackend.h
-	g++ $(FLAGS) -DUSE_EGL $(COMMON_SRC) glutil_gl1.cpp eglbackend.cpp -lEGL -lGL -lX11 -lboost_program_options -o egltest
+	g++ $(FLAGS) -DWIN_EGL -DCON_GL1 $(COMMON_SRC) glutil_gl1.cpp eglbackend.cpp -lEGL -lGL -lX11 -lboost_program_options -o egltest
 
 glestest: $(COMMON_SRC) $(COMMON_HDR) glutil_gl2.cpp eglbackend.cpp eglbackend.h
-	g++ $(FLAGS) -DUSE_EGL -DUSE_GLES $(COMMON_SRC) glutil_gl2.cpp eglbackend.cpp -lEGL -lGLESv2 -lX11 -lboost_program_options -o glestest
+	g++ $(FLAGS) -DWIN_EGL -DCON_GLES2 $(COMMON_SRC) glutil_gl2.cpp eglbackend.cpp -lEGL -lGLESv2 -lX11 -lboost_program_options -o glestest
 
 eglinfo: eglinfo.c
 	gcc $(FLAGS) eglinfo.c -lEGL -lGL -lX11 -o eglinfo
diff --git a/eglbackend.cpp b/eglbackend.cpp
index c5d5bcb..0d5e5e6 100644
--- a/eglbackend.cpp
+++ b/eglbackend.cpp
@@ -24,6 +24,10 @@
 
 #include <EGL/eglext.h>
 
+#if !defined(CON_GL1) && !defined(CON_GLES2)
+#error "Valid GL contexts for EGL are: GL1, GLES2"
+#endif
+
 static const char *eglErrorToString(EGLint e)
 {
 #define CASE(name) case name: return #name
@@ -50,7 +54,7 @@ static void exitEglError(const char *what)
 }
 
 static const EGLint context_attribs[] = {
-#ifdef USE_GLES
+#ifdef CON_GLES2
 	EGL_CONTEXT_CLIENT_VERSION, 2,
 #endif
 	EGL_NONE
@@ -59,7 +63,7 @@ static const EGLint config_attribs[] = {
 	EGL_RED_SIZE,             4,
 	EGL_GREEN_SIZE,           4,
 	EGL_BLUE_SIZE,            4,
-#ifdef USE_GLES
+#ifdef CON_GLES2
 	EGL_RENDERABLE_TYPE,      EGL_OPENGL_ES2_BIT,
 #else
 	EGL_RENDERABLE_TYPE,      EGL_OPENGL_BIT,
@@ -82,7 +86,7 @@ VisualID EGLBackend::initialize(Display *xDisplay)
 			fprintf(stderr, "Need at least EGL 1.3 to function properly\n");
 			exit(1);
 		}
-#ifdef USE_GLES
+#ifdef CON_GLES2
 		if (eglBindAPI(EGL_OPENGL_ES_API) == EGL_FALSE)
 #else
 		if (eglBindAPI(EGL_OPENGL_API) == EGL_FALSE)
diff --git a/gltest.cpp b/gltest.cpp
index 440e8f5..edc17f8 100644
--- a/gltest.cpp
+++ b/gltest.cpp
@@ -31,14 +31,14 @@ namespace po = boost::program_options;
 // my GL utility functions and the GL window class
 #include "glutil.h"
 #include "glwindow.h"
-// include proper GL backend
-#if defined(USE_GLX)
+// include proper GL backend (windowing system)
+#if defined(WIN_GLX)
 #include "glxbackend.h"
 static GLBackend *createGLBackend()
 {
 	return new GLXBackend();
 }
-#elif defined(USE_EGL)
+#elif defined(WIN_EGL)
 #include "eglbackend.h"
 static GLBackend *createGLBackend()
 {
diff --git a/glutil.h b/glutil.h
index 704d2cb..e7a39ad 100644
--- a/glutil.h
+++ b/glutil.h
@@ -17,7 +17,7 @@
  */
 
 
-#ifdef USE_GLES
+#ifdef CON_GLES2
 #include  <GLES2/gl2.h>
 #else
 #include <GL/gl.h>
diff --git a/glutil_gl1.cpp b/glutil_gl1.cpp
index 8e31114..596704e 100644
--- a/glutil_gl1.cpp
+++ b/glutil_gl1.cpp
@@ -18,6 +18,10 @@
 
 #include "glutil.h"
 
+#if defined(CON_GLES2)
+#error "GLES2 contexts do not support GL1 functionality"
+#endif
+
 // initialisation
 void initialise2dProjection()
 {
@@ -37,4 +41,4 @@ void drawQuad(GLfloat red, GLfloat green, GLfloat blue, GLfloat x1, GLfloat y1,
 	glVertex2f(x2, y2);
 	glVertex2f(x1, y2);
 	glEnd();
-}
\ No newline at end of file
+}
diff --git a/glutil_gl2.cpp b/glutil_gl2.cpp
index ebcb5b0..ad89138 100644
--- a/glutil_gl2.cpp
+++ b/glutil_gl2.cpp
@@ -21,6 +21,10 @@
 
 #include "glutil.h"
 
+#if defined(CON_GL1)
+#error "GL1 contexts do not support GL2 functionality"
+#endif
+
 // shaders
 static const char *vertex_shader_source =
 "#version 100 \n\
diff --git a/glxbackend.cpp b/glxbackend.cpp
index a957e5b..97e6937 100644
--- a/glxbackend.cpp
+++ b/glxbackend.cpp
@@ -24,6 +24,10 @@
 #include <GL/glxext.h>
 #include <string>
 
+#if !defined(CON_GL1)
+#error "Valid GL contexts for GLX are: GL1"
+#endif
+
 // attributes for a double buffered visual in RGBA format with at least 4 bits per color
 static int attrList[] =                                             
 {
-- 
2.30.2