michael@0: 
michael@0: /*
michael@0:  * Copyright 2011 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: #include "gl/SkNativeGLContext.h"
michael@0: 
michael@0: #include <GL/glu.h>
michael@0: 
michael@0: #define GLX_1_3 1
michael@0: 
michael@0: SkNativeGLContext::AutoContextRestore::AutoContextRestore() {
michael@0:     fOldGLXContext = glXGetCurrentContext();
michael@0:     fOldDisplay = glXGetCurrentDisplay();
michael@0:     fOldDrawable = glXGetCurrentDrawable();
michael@0: }
michael@0: 
michael@0: SkNativeGLContext::AutoContextRestore::~AutoContextRestore() {
michael@0:     if (NULL != fOldDisplay) {
michael@0:         glXMakeCurrent(fOldDisplay, fOldDrawable, fOldGLXContext);
michael@0:     }
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: static bool ctxErrorOccurred = false;
michael@0: static int ctxErrorHandler(Display *dpy, XErrorEvent *ev) {
michael@0:     ctxErrorOccurred = true;
michael@0:     return 0;
michael@0: }
michael@0: 
michael@0: SkNativeGLContext::SkNativeGLContext()
michael@0:     : fContext(NULL)
michael@0:     , fDisplay(NULL)
michael@0:     , fPixmap(0)
michael@0:     , fGlxPixmap(0) {
michael@0: }
michael@0: 
michael@0: SkNativeGLContext::~SkNativeGLContext() {
michael@0:     this->destroyGLContext();
michael@0: }
michael@0: 
michael@0: void SkNativeGLContext::destroyGLContext() {
michael@0:     if (fDisplay) {
michael@0:         glXMakeCurrent(fDisplay, 0, 0);
michael@0: 
michael@0:         if (fContext) {
michael@0:             glXDestroyContext(fDisplay, fContext);
michael@0:             fContext = NULL;
michael@0:         }
michael@0: 
michael@0:         if (fGlxPixmap) {
michael@0:             glXDestroyGLXPixmap(fDisplay, fGlxPixmap);
michael@0:             fGlxPixmap = 0;
michael@0:         }
michael@0: 
michael@0:         if (fPixmap) {
michael@0:             XFreePixmap(fDisplay, fPixmap);
michael@0:             fPixmap = 0;
michael@0:         }
michael@0: 
michael@0:         XCloseDisplay(fDisplay);
michael@0:         fDisplay = NULL;
michael@0:     }
michael@0: }
michael@0: 
michael@0: const GrGLInterface* SkNativeGLContext::createGLContext() {
michael@0:     fDisplay = XOpenDisplay(0);
michael@0: 
michael@0:     if (!fDisplay) {
michael@0:         SkDebugf("Failed to open X display.\n");
michael@0:         this->destroyGLContext();
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     // Get a matching FB config
michael@0:     static int visual_attribs[] = {
michael@0:         GLX_X_RENDERABLE    , True,
michael@0:         GLX_DRAWABLE_TYPE   , GLX_PIXMAP_BIT,
michael@0:         None
michael@0:     };
michael@0: 
michael@0: #ifdef GLX_1_3
michael@0:     //SkDebugf("Getting matching framebuffer configs.\n");
michael@0:     int fbcount;
michael@0:     GLXFBConfig *fbc = glXChooseFBConfig(fDisplay, DefaultScreen(fDisplay),
michael@0:                                           visual_attribs, &fbcount);
michael@0:     if (!fbc) {
michael@0:         SkDebugf("Failed to retrieve a framebuffer config.\n");
michael@0:         this->destroyGLContext();
michael@0:         return NULL;
michael@0:     }
michael@0:     //SkDebugf("Found %d matching FB configs.\n", fbcount);
michael@0: 
michael@0:     // Pick the FB config/visual with the most samples per pixel
michael@0:     //SkDebugf("Getting XVisualInfos.\n");
michael@0:     int best_fbc = -1, best_num_samp = -1;
michael@0: 
michael@0:     int i;
michael@0:     for (i = 0; i < fbcount; ++i) {
michael@0:         XVisualInfo *vi = glXGetVisualFromFBConfig(fDisplay, fbc[i]);
michael@0:         if (vi) {
michael@0:             int samp_buf, samples;
michael@0:             glXGetFBConfigAttrib(fDisplay, fbc[i], GLX_SAMPLE_BUFFERS, &samp_buf);
michael@0:             glXGetFBConfigAttrib(fDisplay, fbc[i], GLX_SAMPLES, &samples);
michael@0: 
michael@0:             //SkDebugf("  Matching fbconfig %d, visual ID 0x%2x: SAMPLE_BUFFERS = %d,"
michael@0:             //       " SAMPLES = %d\n",
michael@0:             //        i, (unsigned int)vi->visualid, samp_buf, samples);
michael@0: 
michael@0:             if (best_fbc < 0 || (samp_buf && samples > best_num_samp))
michael@0:                 best_fbc = i, best_num_samp = samples;
michael@0:         }
michael@0:         XFree(vi);
michael@0:     }
michael@0: 
michael@0:     GLXFBConfig bestFbc = fbc[best_fbc];
michael@0: 
michael@0:     // Be sure to free the FBConfig list allocated by glXChooseFBConfig()
michael@0:     XFree(fbc);
michael@0: 
michael@0:     // Get a visual
michael@0:     XVisualInfo *vi = glXGetVisualFromFBConfig(fDisplay, bestFbc);
michael@0:     //SkDebugf("Chosen visual ID = 0x%x\n", (unsigned int)vi->visualid);
michael@0: #else
michael@0:     int numVisuals;
michael@0:     XVisualInfo visTemplate, *visReturn;
michael@0: 
michael@0:     visReturn = XGetVisualInfo(fDisplay, VisualNoMask, &visTemplate, &numVisuals);
michael@0:     if (NULL == visReturn)
michael@0:     {
michael@0:         SkDebugf("Failed to get visual information.\n");
michael@0:         this->destroyGLContext();
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     int best = -1, best_num_samp = -1;
michael@0: 
michael@0:     for (int i = 0; i < numVisuals; ++i)
michael@0:     {
michael@0:         int samp_buf, samples;
michael@0: 
michael@0:         glXGetConfig(fDisplay, &visReturn[i], GLX_SAMPLE_BUFFERS, &samp_buf);
michael@0:         glXGetConfig(fDisplay, &visReturn[i], GLX_SAMPLES, &samples);
michael@0: 
michael@0:         if (best < 0 || (samp_buf && samples > best_num_samp))
michael@0:             best = i, best_num_samp = samples;
michael@0:     }
michael@0: 
michael@0:     XVisualInfo temp = visReturn[best];
michael@0:     XVisualInfo *vi = &temp;
michael@0: 
michael@0:     XFree(visReturn);
michael@0: #endif
michael@0: 
michael@0:     fPixmap = XCreatePixmap(fDisplay, RootWindow(fDisplay, vi->screen), 10, 10, vi->depth);
michael@0: 
michael@0:     if (!fPixmap) {
michael@0:         SkDebugf("Failed to create pixmap.\n");
michael@0:         this->destroyGLContext();
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     fGlxPixmap = glXCreateGLXPixmap(fDisplay, vi, fPixmap);
michael@0: 
michael@0: #ifdef GLX_1_3
michael@0:     // Done with the visual info data
michael@0:     XFree(vi);
michael@0: #endif
michael@0: 
michael@0:     // Create the context
michael@0: 
michael@0:     // Install an X error handler so the application won't exit if GL 3.0
michael@0:     // context allocation fails.
michael@0:     //
michael@0:     // Note this error handler is global.
michael@0:     // All display connections in all threads of a process use the same
michael@0:     // error handler, so be sure to guard against other threads issuing
michael@0:     // X commands while this code is running.
michael@0:     ctxErrorOccurred = false;
michael@0:     int (*oldHandler)(Display*, XErrorEvent*) =
michael@0:         XSetErrorHandler(&ctxErrorHandler);
michael@0: 
michael@0:     // Get the default screen's GLX extension list
michael@0:     const char *glxExts = glXQueryExtensionsString(
michael@0:         fDisplay, DefaultScreen(fDisplay)
michael@0:     );
michael@0:     // Check for the GLX_ARB_create_context extension string and the function.
michael@0:     // If either is not present, use GLX 1.3 context creation method.
michael@0:     if (!gluCheckExtension(
michael@0:           reinterpret_cast<const GLubyte*>("GLX_ARB_create_context")
michael@0:           , reinterpret_cast<const GLubyte*>(glxExts)))
michael@0:     {
michael@0:         //SkDebugf("GLX_ARB_create_context not found."
michael@0:         //       " Using old-style GLX context.\n");
michael@0: #ifdef GLX_1_3
michael@0:         fContext = glXCreateNewContext(fDisplay, bestFbc, GLX_RGBA_TYPE, 0, True);
michael@0: #else
michael@0:         fContext = glXCreateContext(fDisplay, vi, 0, True);
michael@0: #endif
michael@0: 
michael@0:     }
michael@0: #ifdef GLX_1_3
michael@0:     else {
michael@0:         //SkDebugf("Creating context.\n");
michael@0: 
michael@0:         PFNGLXCREATECONTEXTATTRIBSARBPROC glXCreateContextAttribsARB =
michael@0:             (PFNGLXCREATECONTEXTATTRIBSARBPROC) glXGetProcAddressARB((GrGLubyte*)"glXCreateContextAttribsARB");
michael@0:         int context_attribs[] = {
michael@0:             GLX_CONTEXT_MAJOR_VERSION_ARB, 3,
michael@0:             GLX_CONTEXT_MINOR_VERSION_ARB, 0,
michael@0:             //GLX_CONTEXT_FLAGS_ARB        , GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB,
michael@0:             None
michael@0:         };
michael@0:         fContext = glXCreateContextAttribsARB(
michael@0:             fDisplay, bestFbc, 0, True, context_attribs
michael@0:         );
michael@0: 
michael@0:         // Sync to ensure any errors generated are processed.
michael@0:         XSync(fDisplay, False);
michael@0:         if (!ctxErrorOccurred && fContext) {
michael@0:            //SkDebugf( "Created GL 3.0 context.\n" );
michael@0:         } else {
michael@0:             // Couldn't create GL 3.0 context.
michael@0:             // Fall back to old-style 2.x context.
michael@0:             // When a context version below 3.0 is requested,
michael@0:             // implementations will return the newest context version compatible
michael@0:             // with OpenGL versions less than version 3.0.
michael@0: 
michael@0:             // GLX_CONTEXT_MAJOR_VERSION_ARB = 1
michael@0:             context_attribs[1] = 1;
michael@0:             // GLX_CONTEXT_MINOR_VERSION_ARB = 0
michael@0:             context_attribs[3] = 0;
michael@0: 
michael@0:             ctxErrorOccurred = false;
michael@0: 
michael@0:             //SkDebugf("Failed to create GL 3.0 context."
michael@0:             //       " Using old-style GLX context.\n");
michael@0:             fContext = glXCreateContextAttribsARB(
michael@0:                 fDisplay, bestFbc, 0, True, context_attribs
michael@0:             );
michael@0:         }
michael@0:     }
michael@0: #endif
michael@0: 
michael@0:     // Sync to ensure any errors generated are processed.
michael@0:     XSync(fDisplay, False);
michael@0: 
michael@0:     // Restore the original error handler
michael@0:     XSetErrorHandler(oldHandler);
michael@0: 
michael@0:     if (ctxErrorOccurred || !fContext) {
michael@0:         SkDebugf("Failed to create an OpenGL context.\n");
michael@0:         this->destroyGLContext();
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     // Verify that context is a direct context
michael@0:     if (!glXIsDirect(fDisplay, fContext)) {
michael@0:         //SkDebugf("Indirect GLX rendering context obtained.\n");
michael@0:     } else {
michael@0:         //SkDebugf("Direct GLX rendering context obtained.\n");
michael@0:     }
michael@0: 
michael@0:     //SkDebugf("Making context current.\n");
michael@0:     if (!glXMakeCurrent(fDisplay, fGlxPixmap, fContext)) {
michael@0:       SkDebugf("Could not set the context.\n");
michael@0:         this->destroyGLContext();
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     const GrGLInterface* interface = GrGLCreateNativeInterface();
michael@0:     if (!interface) {
michael@0:         SkDebugf("Failed to create gl interface");
michael@0:         this->destroyGLContext();
michael@0:         return NULL;
michael@0:     }
michael@0:     return interface;
michael@0: }
michael@0: 
michael@0: void SkNativeGLContext::makeCurrent() const {
michael@0:     if (!glXMakeCurrent(fDisplay, fGlxPixmap, fContext)) {
michael@0:         SkDebugf("Could not set the context.\n");
michael@0:     }
michael@0: }
michael@0: 
michael@0: void SkNativeGLContext::swapBuffers() const {
michael@0:     glXSwapBuffers(fDisplay, fGlxPixmap);
michael@0: }