Add EGL platform opengl implentation

src/x11_egl_opengl.c

@@ -0,0 +1,462 @@
+//========================================================================
+// GLFW - An OpenGL library
+// Platform:    X11/EGL/GLES
+// API version: 3.0
+// WWW:         http://www.glfw.org/
+//------------------------------------------------------------------------
+// Copyright (c) 2002-2006 Marcus Geelnard
+// Copyright (c) 2006-2010 Camilla Berglund <elmindreda@elmindreda.org>
+//
+// This software is provided 'as-is', without any express or implied
+// warranty. In no event will the authors be held liable for any damages
+// arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it
+// freely, subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented; you must not
+//    claim that you wrote the original software. If you use this software
+//    in a product, an acknowledgment in the product documentation would
+//    be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such, and must not
+//    be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source
+//    distribution.
+//
+//========================================================================
+
+#include "internal.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+// Max number of EGL configuration we handle
+#define _GLFW_EGL_CONFIG_IN 15
+
+//========================================================================
+// Returns the specified attribute of the specified EGLConfig
+//========================================================================
+
+static int getFBConfigAttrib(_GLFWwindow* window, EGLConfig fbconfig, int attrib)
+{
+    int value;
+    eglGetConfigAttrib(_glfwLibrary.EGL.display, fbconfig, attrib, &value);
+    return value;
+}
+
+
+//========================================================================
+// Return a list of available and usable framebuffer configs
+//========================================================================
+
+static _GLFWfbconfig* getFBConfigs(_GLFWwindow* window, unsigned int* found)
+{
+    EGLConfig fbconfigs[_GLFW_EGL_CONFIG_IN];
+    _GLFWfbconfig* result;
+    int i, count = 0;
+
+    *found = 0;
+
+
+    eglGetConfigs(_glfwLibrary.EGL.display, fbconfigs,
+            _GLFW_EGL_CONFIG_IN, &count);
+    if (!count)
+    {
+        _glfwSetError(GLFW_OPENGL_UNAVAILABLE,
+                      "X11/EGL: No EGLConfigs returned");
+        return NULL;
+    }
+
+    result = (_GLFWfbconfig*) malloc(sizeof(_GLFWfbconfig) * count);
+    if (!result)
+    {
+        _glfwSetError(GLFW_OUT_OF_MEMORY,
+                      "X11/EGL: Failed to allocate _GLFWfbconfig array");
+        return NULL;
+    }
+
+    for (i = 0;  i < count;  i++)
+    {
+        if (!getFBConfigAttrib(window, fbconfigs[i], EGL_NATIVE_VISUAL_ID))
+        {
+            // Only consider EGLConfigs with associated visuals
+            continue;
+        }
+
+        if (!(getFBConfigAttrib(window,
+                                fbconfigs[i],
+                                EGL_COLOR_BUFFER_TYPE) & EGL_RGB_BUFFER))
+        {
+            // Only consider RGB(A) EGLConfigs
+            continue;
+        }
+
+        if (!(getFBConfigAttrib(window, fbconfigs[i], EGL_RENDERABLE_TYPE) & EGL_WINDOW_BIT))
+        {
+            // Only consider window EGLConfigs
+            continue;
+        }
+
+        result[*found].redBits = getFBConfigAttrib(window, fbconfigs[i], EGL_RED_SIZE);
+        result[*found].greenBits = getFBConfigAttrib(window, fbconfigs[i], EGL_GREEN_SIZE);
+        result[*found].blueBits = getFBConfigAttrib(window, fbconfigs[i], EGL_BLUE_SIZE);
+
+        result[*found].alphaBits = getFBConfigAttrib(window, fbconfigs[i], EGL_ALPHA_SIZE);
+        result[*found].depthBits = getFBConfigAttrib(window, fbconfigs[i], EGL_DEPTH_SIZE);
+        result[*found].stencilBits = getFBConfigAttrib(window, fbconfigs[i], EGL_STENCIL_SIZE);
+
+        result[*found].samples = getFBConfigAttrib(window, fbconfigs[i], EGL_SAMPLES);
+
+        result[*found].platformID = (GLFWintptr) getFBConfigAttrib(window, fbconfigs[i], EGL_CONFIG_ID);
+
+        (*found)++;
+    }
+
+    return result;
+}
+
+//========================================================================
+// Read back framebuffer parameters from the context
+//========================================================================
+
+static void refreshContextParams(_GLFWwindow* window, EGLint fbconfigID)
+{
+    EGLint dummy;
+    EGLConfig fbconfig[_GLFW_EGL_CONFIG_IN];
+
+    int attribs[] = { EGL_CONFIG_ID, fbconfigID, None };
+
+    eglChooseConfig(_glfwLibrary.EGL.display,
+            attribs,
+            fbconfig,
+            _GLFW_EGL_CONFIG_IN,
+            &dummy);
+    if (!dummy)
+    {
+        // This should never ever happen
+        // TODO: Flag this as an error and propagate up
+        _glfwSetError(GLFW_PLATFORM_ERROR, "X11/EGL: Cannot find known "
+                                           "EGLConfig by ID. This cannot "
+                                           "happen. Have a nice day.\n");
+        abort();
+    }
+
+    // There is no clear definition of an "accelerated" context on X11/EGL, and
+    // true sounds better than false, so we hardcode true here
+    window->accelerated = GL_TRUE;
+
+    window->redBits = getFBConfigAttrib(window, *fbconfig, EGL_RED_SIZE);
+    window->greenBits = getFBConfigAttrib(window, *fbconfig, EGL_GREEN_SIZE);
+    window->blueBits = getFBConfigAttrib(window, *fbconfig, EGL_BLUE_SIZE);
+
+    window->alphaBits = getFBConfigAttrib(window, *fbconfig, EGL_ALPHA_SIZE);
+    window->depthBits = getFBConfigAttrib(window, *fbconfig, EGL_DEPTH_SIZE);
+    window->stencilBits = getFBConfigAttrib(window, *fbconfig, EGL_STENCIL_SIZE);
+
+    // Get FSAA buffer sample count
+    window->samples = getFBConfigAttrib(window, *fbconfig, EGL_SAMPLES);
+}
+
+
+//========================================================================
+// Create the actual OpenGL(|ES) context
+//========================================================================
+
+#define setEGLattrib(attribs, index, attribName, attribValue) \
+    attribs[index++] = attribName; \
+    attribs[index++] = attribValue;
+
+static int createContext(_GLFWwindow* window,
+                         const _GLFWwndconfig* wndconfig,
+                         EGLint fbconfigID)
+{
+    int attribs[40];
+    EGLint dummy, index, vid;
+    EGLConfig fbconfig[_GLFW_EGL_CONFIG_IN];
+    EGLContext share = NULL;
+    XVisualInfo visTemplate;
+
+    if (wndconfig->share)
+        share = wndconfig->share->EGL.context;
+
+    // Retrieve the previously selected EGLConfig
+    {
+        index = 0;
+
+        setEGLattrib(attribs, index, EGL_CONFIG_ID, fbconfigID);
+        setEGLattrib(attribs, index, None, None);
+
+        eglChooseConfig(_glfwLibrary.EGL.display,
+                attribs,
+                fbconfig,
+                _GLFW_EGL_CONFIG_IN,
+                &dummy);
+
+        if (!dummy)
+        {
+            _glfwSetError(GLFW_PLATFORM_ERROR,
+                          "X11/EGL: Failed to retrieve the selected EGLConfig");
+            return GL_FALSE;
+        }
+    }
+
+    // Retrieve the corresponding visual
+    if (!eglGetConfigAttrib(_glfwLibrary.EGL.display, *fbconfig, EGL_NATIVE_VISUAL_ID, &vid)) {
+        _glfwSetError(GLFW_PLATFORM_ERROR,
+                "X11/EGL: Failed to retrieve visual for EGLConfig");
+        return GL_FALSE;
+    }
+
+    // The X window visual must match the EGL config
+    visTemplate.visualid = vid;
+    window->EGL.visual = XGetVisualInfo(_glfwLibrary.X11.display, VisualIDMask, &visTemplate, &dummy);
+    if (window->EGL.visual == NULL) {
+        _glfwSetError(GLFW_PLATFORM_ERROR,
+                      "X11/GLX: Failed to retrieve visual for EGLConfig");
+        return GL_FALSE;
+    }
+
+    if (wndconfig->glProfile == GLFW_OPENGL_ES2_PROFILE)
+    {
+        setEGLattrib(attribs, index, EGL_CONTEXT_CLIENT_VERSION, 2);
+    }
+    else
+    {
+        setEGLattrib(attribs, index, EGL_CONTEXT_CLIENT_VERSION, 1);
+    }
+
+    setEGLattrib(attribs, index, EGL_NONE, EGL_NONE);
+
+    eglBindAPI(EGL_OPENGL_ES_API);
+
+    window->EGL.context = eglCreateContext(_glfwLibrary.EGL.display, *fbconfig, share, attribs);
+    if (window->EGL.context == EGL_NO_CONTEXT)
+    {
+        // TODO: Handle all the various error codes here
+
+        _glfwSetError(GLFW_PLATFORM_ERROR,
+                      "X11/EGL: Failed to create OpenGL(|ES) context");
+        return GL_FALSE;
+    }
+
+    refreshContextParams(window, fbconfigID);
+
+    return GL_TRUE;
+}
+
+#undef setEGLattrib
+
+
+//////////////////////////////////////////////////////////////////////////
+//////                       GLFW internal API                      //////
+//////////////////////////////////////////////////////////////////////////
+
+//========================================================================
+// Initialize EGL
+//========================================================================
+
+int _glfwInitOpenGL(void)
+{
+#ifdef _GLFW_DLOPEN_LIBGL
+    int i;
+    char* libEGL_names[ ] =
+    {
+        "libEGL.so",
+        "libEGL.so.1",
+        "/usr/lib/libEGL.so",
+        "/usr/lib/libEGL.so.1",
+        NULL
+    };
+
+    for (i = 0;  libEGL_names[i] != NULL;  i++)
+    {
+        _glfwLibrary.EGL.libEGL = dlopen(libEGL_names[i], RTLD_LAZY | RTLD_GLOBAL);
+        if (_glfwLibrary.EGL.libEGL)
+            break;
+    }
+
+    if (!_glfwLibrary.EGL.libEGL)
+    {
+        _glfwSetError(GLFW_PLATFORM_ERROR, "X11/EGL: Failed to find libEGL");
+        return GL_FALSE;
+    }
+#endif
+
+    _glfwLibrary.EGL.display = eglGetDisplay((EGLNativeDisplayType)_glfwLibrary.X11.display);
+    if (_glfwLibrary.EGL.display == EGL_NO_DISPLAY)
+    {
+        _glfwSetError(GLFW_OPENGL_UNAVAILABLE,
+                      "X11/EGL: Failed to get EGL display");
+        return GL_FALSE;
+    }
+
+    if (!eglInitialize(_glfwLibrary.EGL.display,
+                &_glfwLibrary.EGL.majorVersion,
+                &_glfwLibrary.EGL.minorVersion))
+    {
+        _glfwSetError(GLFW_OPENGL_UNAVAILABLE,
+                      "X11/EGL: Failed to initialize EGL");
+        return GL_FALSE;
+    }
+
+    return GL_TRUE;
+}
+
+
+//========================================================================
+// Terminate EGL
+//========================================================================
+
+void _glfwTerminateOpenGL(void)
+{
+    // Unload libEGL.so if necessary
+#ifdef _GLFW_DLOPEN_LIBGL
+    if (_glfwLibrary.EGL.libEGL != NULL)
+    {
+        dlclose(_glfwLibrary.EGL.libEGL);
+        _glfwLibrary.EGL.libEGL = NULL;
+    }
+#endif
+    eglTerminate(_glfwLibrary.EGL.display);
+}
+
+
+//========================================================================
+// Prepare for creation of the OpenGL context
+//========================================================================
+
+int _glfwCreateContext(_GLFWwindow* window,
+                       const _GLFWwndconfig* wndconfig,
+                       const _GLFWfbconfig* fbconfig)
+{
+    _GLFWfbconfig closest;
+
+    // Choose the best available fbconfig
+    {
+        unsigned int fbcount;
+        _GLFWfbconfig* fbconfigs;
+        const _GLFWfbconfig* result;
+
+        fbconfigs = getFBConfigs(window, &fbcount);
+        if (!fbconfigs)
+        {
+            _glfwSetError(GLFW_PLATFORM_ERROR,
+                          "X11/EGL: No usable EGLFBConfigs found");
+            return GL_FALSE;
+        }
+
+        result = _glfwChooseFBConfig(fbconfig, fbconfigs, fbcount);
+        if (!result)
+        {
+            _glfwSetError(GLFW_PLATFORM_ERROR,
+                          "X11/EGL: No EGLFBConfig matched the criteria");
+
+            free(fbconfigs);
+            return GL_FALSE;
+        }
+
+        closest = *result;
+        free(fbconfigs);
+    }
+
+    return createContext(window, wndconfig, closest.platformID);
+}
+
+
+//========================================================================
+// Destroy the OpenGL context
+//========================================================================
+
+void _glfwDestroyContext(_GLFWwindow* window)
+{
+    if (window->EGL.context)
+    {
+        // Release and destroy the context
+        eglMakeCurrent(_glfwLibrary.EGL.display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+        window->EGL.context = NULL;
+    }
+}
+
+
+//========================================================================
+// Make the OpenGL context associated with the specified window current
+//========================================================================
+
+void _glfwPlatformMakeContextCurrent(_GLFWwindow* window)
+{
+    if (window)
+    {
+        eglMakeCurrent(_glfwLibrary.EGL.display,
+                       window->EGL.surface,
+                       window->EGL.surface,
+                       window->EGL.context);
+    }
+    else
+        eglMakeCurrent(_glfwLibrary.EGL.display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
+}
+
+
+//========================================================================
+// Swap OpenGL buffers
+//========================================================================
+
+void _glfwPlatformSwapBuffers(void)
+{
+    eglSwapBuffers(_glfwLibrary.EGL.display,
+                   _glfwLibrary.currentWindow->EGL.surface);
+}
+
+
+//========================================================================
+// Set double buffering swap interval
+//========================================================================
+
+void _glfwPlatformSwapInterval(int interval)
+{
+    eglSwapInterval(_glfwLibrary.EGL.display, interval);
+}
+
+
+//========================================================================
+// Check if an OpenGL extension is available at runtime
+//========================================================================
+
+int _glfwPlatformExtensionSupported(const char* extension)
+{
+    const char* extensions;
+
+    // Get list of GLX extensions
+    extensions = eglQueryString(_glfwLibrary.EGL.display,
+                                EGL_EXTENSIONS);
+    if (extensions != NULL)
+    {
+        if (_glfwStringInExtensionString(extension, (unsigned char*)extensions))
+            return GL_TRUE;
+    }
+
+    return GL_FALSE;
+}
+
+
+//========================================================================
+// Get the function pointer to an OpenGL function
+//========================================================================
+
+void* _glfwPlatformGetProcAddress(const char* procname)
+{
+    return (void*) _glfw_eglGetProcAddress(procname);
+}
+
+
+//========================================================================
+// Copies the specified OpenGL state categories from src to dst
+//========================================================================
+
+void _glfwPlatformCopyContext(_GLFWwindow* src, _GLFWwindow* dst, unsigned long mask)
+{
+    // AFAIK, EGL doesn't have this
+}
+