Add support for OpenGL 3 contexts
[gltest.git] / eglbackend.cpp
index cbe724cff375cbb5e22329d4f593bfdd437102ca..0d765e9cb64116d3a5455d0f8050e05548a8a38b 100644 (file)
@@ -17,6 +17,7 @@
  */
 
 #include "eglbackend.h"
+#include "glutil.h"
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -53,13 +54,7 @@ static void exitEglError(const char *what)
        exit(1);
 }
 
-static const EGLint context_attribs[] = {
-#ifdef CON_GLES2
-       EGL_CONTEXT_CLIENT_VERSION, 2,
-#endif
-       EGL_NONE
-};
-static const EGLint config_attribs[] = {
+static const EGLint configAttribs[] = {
        EGL_RED_SIZE,             4,
        EGL_GREEN_SIZE,           4,
        EGL_BLUE_SIZE,            4,
@@ -70,6 +65,12 @@ static const EGLint config_attribs[] = {
 #endif
        EGL_NONE,
 };
+static const EGLint contextAttribs[] = {
+#ifdef CON_GLES2
+       EGL_CONTEXT_CLIENT_VERSION, 2,
+#endif
+       EGL_NONE
+};
 
 VisualID EGLBackend::initialize(Display *xDisplay)
 {
@@ -83,6 +84,7 @@ VisualID EGLBackend::initialize(Display *xDisplay)
                        exitEglError("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
                        fprintf(stderr, "Need at least EGL 1.3 to function properly\n");
                        exit(1);
                }
@@ -95,11 +97,11 @@ VisualID EGLBackend::initialize(Display *xDisplay)
                // get an appropriate config
                EGLConfig configs[1];
                EGLint count;
-               if (eglChooseConfig(display, config_attribs, configs, 1, &count) == EGL_FALSE){
-                       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 EGL configuration\n");
+                       fprintf(stderr, "Found no matching framebuffer configuration\n");
                        exit(1);
                }
                config = configs[0];
@@ -115,11 +117,14 @@ 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, context_attribs);
+       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()
@@ -146,12 +151,11 @@ void EGLBackend::setSwapInterval(int i) const
 {
        assert(context != EGL_NO_CONTEXT);
        // check if swap interval value is supported
-       EGLint val;
-       eglGetConfigAttrib(display, config, EGL_MIN_SWAP_INTERVAL, &val);
-       if (i < val) {
-               fprintf(stderr, "Cannot set swap interval to %d, minimum supported value is %d\n", i, val);
+       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);