Add support for OpenGL 3 contexts

[gltest.git] / eglbackend.cpp

diff --git a/eglbackend.cpp b/eglbackend.cpp
index 0e4c9378edc16d4f3004dfa463a68e4a75e7133d..0d765e9cb64116d3a5455d0f8050e05548a8a38b 100644 (file)
--- a/eglbackend.cpp
+++ b/eglbackend.cpp
@@ -17,6 +17,7 @@
  */
 
 #include "eglbackend.h"
+#include "glutil.h"
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -24,6 +25,10 @@
 
 #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
@@ -49,15 +54,23 @@ static void exitEglError(const char *what)
        exit(1);
 }
 
-/* attributes for a double buffered visual in RGBA format with at least
-* 4 bits per color */
-static const EGLint config_attribs[] = {
+static const EGLint configAttribs[] = {
        EGL_RED_SIZE,             4,
        EGL_GREEN_SIZE,           4,
        EGL_BLUE_SIZE,            4,
+#ifdef CON_GLES2
+       EGL_RENDERABLE_TYPE,      EGL_OPENGL_ES2_BIT,
+#else
        EGL_RENDERABLE_TYPE,      EGL_OPENGL_BIT,
+#endif
        EGL_NONE,
 };
+static const EGLint contextAttribs[] = {
+#ifdef CON_GLES2
+       EGL_CONTEXT_CLIENT_VERSION, 2,
+#endif
+       EGL_NONE
+};
 
 VisualID EGLBackend::initialize(Display *xDisplay)
 {
@@ -65,17 +78,32 @@ VisualID EGLBackend::initialize(Display *xDisplay)
                // get connection and bind API
                EGLint eglMajor, eglMinor;
                display = eglGetDisplay(xDisplay);
-               if (display == EGL_NO_DISPLAY)                         
+               if (display == EGL_NO_DISPLAY)
                        exitEglError("Failed to get EGL display");
-               if (eglInitialize(display, &eglMajor, &eglMinor) == EGL_FALSE)                   
+               if (eglInitialize(display, &eglMajor, &eglMinor) == EGL_FALSE)
                        exitEglError("Failed to initialize EGL");
-               printf("Using EGL version %d.%d\n", eglMajor, eglMinor);
-               eglBindAPI(EGL_OPENGL_API);
+               printf("Using EGL version: %d.%d\n", eglMajor, eglMinor);
+               if (eglMajor == 1 && eglMinor < 3) {
+                       // Choosing the GL context version requires EGL 1.3
+                       fprintf(stderr, "Need at least EGL 1.3 to function properly\n");
+                       exit(1);
+               }
+#ifdef CON_GLES2
+               if (eglBindAPI(EGL_OPENGL_ES_API) == EGL_FALSE)
+#else
+               if (eglBindAPI(EGL_OPENGL_API) == EGL_FALSE)
+#endif
+                       exitEglError("Failed to bind API");
                // get an appropriate config
                EGLConfig configs[1];
                EGLint count;
-               if (eglChooseConfig(display, config_attribs, configs, 1, &count) == EGL_FALSE || count == 0)                            
-                       exitEglError("Failed to choose config");
+               if (eglChooseConfig(display, configAttribs, configs, 1, &count) == EGL_FALSE){
+                       exitEglError("Failed to choose framebuffer configuration");
+               }
+               if (count == 0) {
+                       fprintf(stderr, "Found no matching framebuffer configuration\n");
+                       exit(1);
+               }
                config = configs[0];
        }
        // return visual ID
@@ -88,12 +116,15 @@ void EGLBackend::createContext(Window window)
 {
        assert(display != EGL_NO_DISPLAY && context == EGL_NO_CONTEXT);
        surface = eglCreateWindowSurface(display, config, window, NULL);
-       /* create an EGL context and use it with the surface */                                    
-       context = eglCreateContext(display, config, EGL_NO_CONTEXT, NULL);
+       // create an EGL context and use it with the surface
+       context = eglCreateContext(display, config, EGL_NO_CONTEXT, contextAttribs);
        if (context == EGL_NO_CONTEXT)
                exitEglError("Failed to create context");
        if (eglMakeCurrent(display, surface, surface, context) == EGL_FALSE)
                exitEglError("Failed to make context current");
+       printf("Using GL version: %s\n", glGetString(GL_VERSION));
+       // initialise GL utilities
+       resolveFunctionPointers(eglGetProcAddress);
 }
 
 EGLBackend::~EGLBackend()
@@ -112,11 +143,25 @@ EGLBackend::~EGLBackend()
 void EGLBackend::swapBuffers() const
 {
        assert(context != EGL_NO_CONTEXT); // this implies the display is also initialized
-       eglSwapBuffers(display, surface);
+       if (eglSwapBuffers(display, surface) == EGL_FALSE)
+               exitEglError("Failed to swap buffers");
 }
 
 void EGLBackend::setSwapInterval(int i) const
 {
        assert(context != EGL_NO_CONTEXT);
-       eglSwapInterval(display, i);
+       // check if swap interval value is supported
+       if (i < 0) {
+               fprintf(stderr, "Cannot set swap interval to %d, must not be negative\n", i);
+               exit(1);
+       }
+       EGLint val;
+       eglGetConfigAttrib(display, config, EGL_MAX_SWAP_INTERVAL, &val);
+       if (i > val) {
+               fprintf(stderr, "Cannot set swap interval to %d, maximum supported value is %d\n", i, val);
+               exit(1);
+       }
+       // use it
+       if (eglSwapInterval(display, i) == EGL_FALSE)
+               exitEglError("Failed to set swap interval");
 }