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      1 
      2 /*
      3  * Copyright 2013 Google Inc.
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 #include "gl/SkGLContextHelper.h"
      9 #include "GrGLUtil.h"
     10 
     11 SkGLContextHelper::SkGLContextHelper()
     12     : fFBO(0)
     13     , fColorBufferID(0)
     14     , fDepthStencilBufferID(0)
     15     , fGL(NULL) {
     16 }
     17 
     18 SkGLContextHelper::~SkGLContextHelper() {
     19 
     20     if (fGL) {
     21         // TODO: determine why DeleteFramebuffers is generating a GL error in tests
     22         SK_GL_NOERRCHECK(*this, DeleteFramebuffers(1, &fFBO));
     23         SK_GL_NOERRCHECK(*this, DeleteRenderbuffers(1, &fColorBufferID));
     24         SK_GL_NOERRCHECK(*this, DeleteRenderbuffers(1, &fDepthStencilBufferID));
     25     }
     26 
     27     SkSafeUnref(fGL);
     28 }
     29 
     30 bool SkGLContextHelper::init(int width, int height) {
     31     if (fGL) {
     32         fGL->unref();
     33         this->destroyGLContext();
     34     }
     35 
     36     fGL = this->createGLContext();
     37     if (fGL) {
     38         const GrGLubyte* temp;
     39 
     40         GrGLBinding bindingInUse = GrGLGetBindingInUse(this->gl());
     41 
     42         if (!fGL->validate(bindingInUse) || !fExtensions.init(bindingInUse, fGL)) {
     43             fGL = NULL;
     44             this->destroyGLContext();
     45             return false;
     46         }
     47 
     48         SK_GL_RET(*this, temp, GetString(GR_GL_VERSION));
     49         const char* versionStr = reinterpret_cast<const char*>(temp);
     50         GrGLVersion version = GrGLGetVersionFromString(versionStr);
     51 
     52         // clear any existing GL erorrs
     53         GrGLenum error;
     54         do {
     55             SK_GL_RET(*this, error, GetError());
     56         } while (GR_GL_NO_ERROR != error);
     57 
     58         SK_GL(*this, GenFramebuffers(1, &fFBO));
     59         SK_GL(*this, BindFramebuffer(GR_GL_FRAMEBUFFER, fFBO));
     60         SK_GL(*this, GenRenderbuffers(1, &fColorBufferID));
     61         SK_GL(*this, BindRenderbuffer(GR_GL_RENDERBUFFER, fColorBufferID));
     62         if (kES_GrGLBinding == bindingInUse) {
     63             SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
     64                                              GR_GL_RGBA8,
     65                                              width, height));
     66         } else {
     67             SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
     68                                              GR_GL_RGBA,
     69                                              width, height));
     70         }
     71         SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
     72                                              GR_GL_COLOR_ATTACHMENT0,
     73                                              GR_GL_RENDERBUFFER,
     74                                              fColorBufferID));
     75         SK_GL(*this, GenRenderbuffers(1, &fDepthStencilBufferID));
     76         SK_GL(*this, BindRenderbuffer(GR_GL_RENDERBUFFER, fDepthStencilBufferID));
     77 
     78         // Some drivers that support packed depth stencil will only succeed
     79         // in binding a packed format an FBO. However, we can't rely on packed
     80         // depth stencil being available.
     81         bool supportsPackedDepthStencil;
     82         if (kES_GrGLBinding == bindingInUse) {
     83             supportsPackedDepthStencil = version >= GR_GL_VER(3,0) ||
     84                                          this->hasExtension("GL_OES_packed_depth_stencil");
     85         } else {
     86             supportsPackedDepthStencil = version >= GR_GL_VER(3,0) ||
     87                                          this->hasExtension("GL_EXT_packed_depth_stencil") ||
     88                                          this->hasExtension("GL_ARB_framebuffer_object");
     89         }
     90 
     91         if (supportsPackedDepthStencil) {
     92             // ES2 requires sized internal formats for RenderbufferStorage
     93             // On Desktop we let the driver decide.
     94             GrGLenum format = kES_GrGLBinding == bindingInUse ?
     95                                     GR_GL_DEPTH24_STENCIL8 :
     96                                     GR_GL_DEPTH_STENCIL;
     97             SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
     98                                              format,
     99                                              width, height));
    100             SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
    101                                                  GR_GL_DEPTH_ATTACHMENT,
    102                                                  GR_GL_RENDERBUFFER,
    103                                                  fDepthStencilBufferID));
    104         } else {
    105             GrGLenum format = kES_GrGLBinding == bindingInUse ?
    106                                     GR_GL_STENCIL_INDEX8 :
    107                                     GR_GL_STENCIL_INDEX;
    108             SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
    109                                              format,
    110                                              width, height));
    111         }
    112         SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
    113                                              GR_GL_STENCIL_ATTACHMENT,
    114                                              GR_GL_RENDERBUFFER,
    115                                              fDepthStencilBufferID));
    116         SK_GL(*this, Viewport(0, 0, width, height));
    117         SK_GL(*this, ClearStencil(0));
    118         SK_GL(*this, Clear(GR_GL_STENCIL_BUFFER_BIT));
    119 
    120         SK_GL_RET(*this, error, GetError());
    121         GrGLenum status;
    122         SK_GL_RET(*this, status, CheckFramebufferStatus(GR_GL_FRAMEBUFFER));
    123 
    124         if (GR_GL_FRAMEBUFFER_COMPLETE != status ||
    125             GR_GL_NO_ERROR != error) {
    126             fFBO = 0;
    127             fColorBufferID = 0;
    128             fDepthStencilBufferID = 0;
    129             fGL->unref();
    130             fGL = NULL;
    131             this->destroyGLContext();
    132             return false;
    133         } else {
    134             return true;
    135         }
    136     }
    137     return false;
    138 }
    139