Revert of Make the Sk GL context class an abstract base class

src/gpu/gl/glx/SkNativeGLContext_glx.cpp

Index: src/gpu/gl/glx/SkNativeGLContext_glx.cpp
diff --git a/src/gpu/gl/glx/SkNativeGLContext_glx.cpp b/src/gpu/gl/glx/SkNativeGLContext_glx.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..bd130b545cd9af62de9002dfbc6aef2f0e4b85da
--- /dev/null
+++ b/src/gpu/gl/glx/SkNativeGLContext_glx.cpp
@@ -0,0 +1,288 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "gl/SkNativeGLContext.h"
+
+#include <GL/glu.h>
+
+/* Note: Skia requires glx 1.3 or newer */
+
+SkNativeGLContext::AutoContextRestore::AutoContextRestore() {
+    fOldGLXContext = glXGetCurrentContext();
+    fOldDisplay = glXGetCurrentDisplay();
+    fOldDrawable = glXGetCurrentDrawable();
+}
+
+SkNativeGLContext::AutoContextRestore::~AutoContextRestore() {
+    if (fOldDisplay) {
+        glXMakeCurrent(fOldDisplay, fOldDrawable, fOldGLXContext);
+    }
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+static bool ctxErrorOccurred = false;
+static int ctxErrorHandler(Display *dpy, XErrorEvent *ev) {
+    ctxErrorOccurred = true;
+    return 0;
+}
+
+SkNativeGLContext::SkNativeGLContext()
+    : fContext(NULL)
+    , fDisplay(NULL)
+    , fPixmap(0)
+    , fGlxPixmap(0) {
+}
+
+SkNativeGLContext::~SkNativeGLContext() {
+    this->destroyGLContext();
+}
+
+void SkNativeGLContext::destroyGLContext() {
+    if (fDisplay) {
+        glXMakeCurrent(fDisplay, 0, 0);
+
+        if (fContext) {
+            glXDestroyContext(fDisplay, fContext);
+            fContext = NULL;
+        }
+
+        if (fGlxPixmap) {
+            glXDestroyGLXPixmap(fDisplay, fGlxPixmap);
+            fGlxPixmap = 0;
+        }
+
+        if (fPixmap) {
+            XFreePixmap(fDisplay, fPixmap);
+            fPixmap = 0;
+        }
+
+        XCloseDisplay(fDisplay);
+        fDisplay = NULL;
+    }
+}
+
+const GrGLInterface* SkNativeGLContext::createGLContext(GrGLStandard forcedGpuAPI) {
+    fDisplay = XOpenDisplay(0);
+
+    if (!fDisplay) {
+        SkDebugf("Failed to open X display.\n");
+        this->destroyGLContext();
+        return NULL;
+    }
+
+    // Get a matching FB config
+    static int visual_attribs[] = {
+        GLX_X_RENDERABLE    , True,
+        GLX_DRAWABLE_TYPE   , GLX_PIXMAP_BIT,
+        None
+    };
+
+    int glx_major, glx_minor;
+
+    // FBConfigs were added in GLX version 1.3.
+    if (!glXQueryVersion(fDisplay, &glx_major, &glx_minor) ||
+            ((glx_major == 1) && (glx_minor < 3)) || (glx_major < 1)) {
+        SkDebugf("GLX version 1.3 or higher required.\n");
+        this->destroyGLContext();
+        return NULL;
+    }
+
+    //SkDebugf("Getting matching framebuffer configs.\n");
+    int fbcount;
+    GLXFBConfig *fbc = glXChooseFBConfig(fDisplay, DefaultScreen(fDisplay),
+                                          visual_attribs, &fbcount);
+    if (!fbc) {
+        SkDebugf("Failed to retrieve a framebuffer config.\n");
+        this->destroyGLContext();
+        return NULL;
+    }
+    //SkDebugf("Found %d matching FB configs.\n", fbcount);
+
+    // Pick the FB config/visual with the most samples per pixel
+    //SkDebugf("Getting XVisualInfos.\n");
+    int best_fbc = -1, best_num_samp = -1;
+
+    int i;
+    for (i = 0; i < fbcount; ++i) {
+        XVisualInfo *vi = glXGetVisualFromFBConfig(fDisplay, fbc[i]);
+        if (vi) {
+            int samp_buf, samples;
+            glXGetFBConfigAttrib(fDisplay, fbc[i], GLX_SAMPLE_BUFFERS, &samp_buf);
+            glXGetFBConfigAttrib(fDisplay, fbc[i], GLX_SAMPLES, &samples);
+
+            //SkDebugf("  Matching fbconfig %d, visual ID 0x%2x: SAMPLE_BUFFERS = %d,"
+            //       " SAMPLES = %d\n",
+            //        i, (unsigned int)vi->visualid, samp_buf, samples);
+
+            if (best_fbc < 0 || (samp_buf && samples > best_num_samp))
+                best_fbc = i, best_num_samp = samples;
+        }
+        XFree(vi);
+    }
+
+    GLXFBConfig bestFbc = fbc[best_fbc];
+
+    // Be sure to free the FBConfig list allocated by glXChooseFBConfig()
+    XFree(fbc);
+
+    // Get a visual
+    XVisualInfo *vi = glXGetVisualFromFBConfig(fDisplay, bestFbc);
+    //SkDebugf("Chosen visual ID = 0x%x\n", (unsigned int)vi->visualid);
+
+    fPixmap = XCreatePixmap(fDisplay, RootWindow(fDisplay, vi->screen), 10, 10, vi->depth);
+
+    if (!fPixmap) {
+        SkDebugf("Failed to create pixmap.\n");
+        this->destroyGLContext();
+        return NULL;
+    }
+
+    fGlxPixmap = glXCreateGLXPixmap(fDisplay, vi, fPixmap);
+
+    // Done with the visual info data
+    XFree(vi);
+
+    // Create the context
+
+    // Install an X error handler so the application won't exit if GL 3.0
+    // context allocation fails.
+    //
+    // Note this error handler is global.
+    // All display connections in all threads of a process use the same
+    // error handler, so be sure to guard against other threads issuing
+    // X commands while this code is running.
+    ctxErrorOccurred = false;
+    int (*oldHandler)(Display*, XErrorEvent*) =
+        XSetErrorHandler(&ctxErrorHandler);
+
+    // Get the default screen's GLX extension list
+    const char *glxExts = glXQueryExtensionsString(
+        fDisplay, DefaultScreen(fDisplay)
+    );
+
+
+    // Check for the GLX_ARB_create_context extension string and the function.
+    // If either is not present, use GLX 1.3 context creation method.
+    if (!gluCheckExtension(reinterpret_cast<const GLubyte*>("GLX_ARB_create_context"),
+                           reinterpret_cast<const GLubyte*>(glxExts))) {
+        if (kGLES_GrGLStandard != forcedGpuAPI) {
+            fContext = glXCreateNewContext(fDisplay, bestFbc, GLX_RGBA_TYPE, 0, True);
+        }
+    } else {
+        //SkDebugf("Creating context.\n");
+        PFNGLXCREATECONTEXTATTRIBSARBPROC glXCreateContextAttribsARB =
+            (PFNGLXCREATECONTEXTATTRIBSARBPROC) glXGetProcAddressARB((GrGLubyte*)"glXCreateContextAttribsARB");
+
+        if (kGLES_GrGLStandard == forcedGpuAPI) {
+            if (gluCheckExtension(
+                    reinterpret_cast<const GLubyte*>("GLX_EXT_create_context_es2_profile"),
+                    reinterpret_cast<const GLubyte*>(glxExts))) {
+                static const int context_attribs_gles[] = {
+                    GLX_CONTEXT_MAJOR_VERSION_ARB, 3,
+                    GLX_CONTEXT_MINOR_VERSION_ARB, 0,
+                    GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_ES2_PROFILE_BIT_EXT,
+                    None
+                };
+                fContext = glXCreateContextAttribsARB(fDisplay, bestFbc, 0, True,
+                                                      context_attribs_gles);
+            }
+        } else {
+            // Well, unfortunately GLX will not just give us the highest context so instead we have
+            // to do this nastiness
+            for (i = NUM_GL_VERSIONS - 2; i > 0 ; i--) {
+                /* don't bother below GL 3.0 */
+                if (gl_versions[i].major == 3 && gl_versions[i].minor == 0) {
+                    break;
+                }
+                // On Nvidia GPUs, to use Nv Path rendering we need a compatibility profile for the
+                // time being.
+                // TODO when Nvidia implements NVPR on Core profiles, we should start requesting
+                // core here
+                static const int context_attribs_gl[] = {
+                      GLX_CONTEXT_MAJOR_VERSION_ARB, gl_versions[i].major,
+                      GLX_CONTEXT_MINOR_VERSION_ARB, gl_versions[i].minor,
+                      GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB,
+                      None
+                };
+                fContext =
+                        glXCreateContextAttribsARB(fDisplay, bestFbc, 0, True, context_attribs_gl);
+
+                // Sync to ensure any errors generated are processed.
+                XSync(fDisplay, False);
+
+                if (!ctxErrorOccurred && fContext) {
+                    break;
+                }
+                // try again
+                ctxErrorOccurred = false;
+            }
+
+            // Couldn't create GL 3.0 context.
+            // Fall back to old-style 2.x context.
+            // When a context version below 3.0 is requested,
+            // implementations will return the newest context version
+            // compatible with OpenGL versions less than version 3.0.
+            if (ctxErrorOccurred || !fContext) {
+                static const int context_attribs_gl_fallback[] = {
+                    GLX_CONTEXT_MAJOR_VERSION_ARB, 1,
+                    GLX_CONTEXT_MINOR_VERSION_ARB, 0,
+                    None
+                };
+
+                ctxErrorOccurred = false;
+
+                fContext = glXCreateContextAttribsARB(fDisplay, bestFbc, 0, True,
+                                                      context_attribs_gl_fallback);
+            }
+        }
+    }
+
+    // Sync to ensure any errors generated are processed.
+    XSync(fDisplay, False);
+
+    // Restore the original error handler
+    XSetErrorHandler(oldHandler);
+
+    if (ctxErrorOccurred || !fContext) {
+        SkDebugf("Failed to create an OpenGL context.\n");
+        this->destroyGLContext();
+        return NULL;
+    }
+
+    // Verify that context is a direct context
+    if (!glXIsDirect(fDisplay, fContext)) {
+        //SkDebugf("Indirect GLX rendering context obtained.\n");
+    } else {
+        //SkDebugf("Direct GLX rendering context obtained.\n");
+    }
+
+    //SkDebugf("Making context current.\n");
+    if (!glXMakeCurrent(fDisplay, fGlxPixmap, fContext)) {
+      SkDebugf("Could not set the context.\n");
+        this->destroyGLContext();
+        return NULL;
+    }
+
+    const GrGLInterface* interface = GrGLCreateNativeInterface();
+    if (!interface) {
+        SkDebugf("Failed to create gl interface");
+        this->destroyGLContext();
+        return NULL;
+    }
+    return interface;
+}
+
+void SkNativeGLContext::makeCurrent() const {
+    if (!glXMakeCurrent(fDisplay, fGlxPixmap, fContext)) {
+        SkDebugf("Could not set the context.\n");
+    }
+}
+
+void SkNativeGLContext::swapBuffers() const {
+    glXSwapBuffers(fDisplay, fGlxPixmap);
+}