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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         if (!fGL->validate()) {
     41             fGL = NULL;
     42             this->destroyGLContext();
     43             return false;
     44         }
     45 
     46         SK_GL_RET(*this, temp, GetString(GR_GL_VERSION));
     47         const char* versionStr = reinterpret_cast<const char*>(temp);
     48         GrGLVersion version = GrGLGetVersionFromString(versionStr);
     49 
     50         // clear any existing GL erorrs
     51         GrGLenum error;
     52         do {
     53             SK_GL_RET(*this, error, GetError());
     54         } while (GR_GL_NO_ERROR != error);
     55 
     56         SK_GL(*this, GenFramebuffers(1, &fFBO));
     57         SK_GL(*this, BindFramebuffer(GR_GL_FRAMEBUFFER, fFBO));
     58         SK_GL(*this, GenRenderbuffers(1, &fColorBufferID));
     59         SK_GL(*this, BindRenderbuffer(GR_GL_RENDERBUFFER, fColorBufferID));
     60         if (kGLES_GrGLStandard == this->gl()->fStandard) {
     61             SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
     62                                              GR_GL_RGBA8,
     63                                              width, height));
     64         } else {
     65             SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
     66                                              GR_GL_RGBA,
     67                                              width, height));
     68         }
     69         SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
     70                                              GR_GL_COLOR_ATTACHMENT0,
     71                                              GR_GL_RENDERBUFFER,
     72                                              fColorBufferID));
     73         SK_GL(*this, GenRenderbuffers(1, &fDepthStencilBufferID));
     74         SK_GL(*this, BindRenderbuffer(GR_GL_RENDERBUFFER, fDepthStencilBufferID));
     75 
     76         // Some drivers that support packed depth stencil will only succeed
     77         // in binding a packed format an FBO. However, we can't rely on packed
     78         // depth stencil being available.
     79         bool supportsPackedDepthStencil;
     80         if (kGLES_GrGLStandard == this->gl()->fStandard) {
     81             supportsPackedDepthStencil = version >= GR_GL_VER(3,0) ||
     82                                          this->hasExtension("GL_OES_packed_depth_stencil");
     83         } else {
     84             supportsPackedDepthStencil = version >= GR_GL_VER(3,0) ||
     85                                          this->hasExtension("GL_EXT_packed_depth_stencil") ||
     86                                          this->hasExtension("GL_ARB_framebuffer_object");
     87         }
     88 
     89         if (supportsPackedDepthStencil) {
     90             // ES2 requires sized internal formats for RenderbufferStorage
     91             // On Desktop we let the driver decide.
     92             GrGLenum format = kGLES_GrGLStandard == this->gl()->fStandard ?
     93                                     GR_GL_DEPTH24_STENCIL8 :
     94                                     GR_GL_DEPTH_STENCIL;
     95             SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
     96                                              format,
     97                                              width, height));
     98             SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
     99                                                  GR_GL_DEPTH_ATTACHMENT,
    100                                                  GR_GL_RENDERBUFFER,
    101                                                  fDepthStencilBufferID));
    102         } else {
    103             GrGLenum format = kGLES_GrGLStandard == this->gl()->fStandard ? GR_GL_STENCIL_INDEX8 :
    104                                                                           GR_GL_STENCIL_INDEX;
    105             SK_GL(*this, RenderbufferStorage(GR_GL_RENDERBUFFER,
    106                                              format,
    107                                              width, height));
    108         }
    109         SK_GL(*this, FramebufferRenderbuffer(GR_GL_FRAMEBUFFER,
    110                                              GR_GL_STENCIL_ATTACHMENT,
    111                                              GR_GL_RENDERBUFFER,
    112                                              fDepthStencilBufferID));
    113         SK_GL(*this, Viewport(0, 0, width, height));
    114         SK_GL(*this, ClearStencil(0));
    115         SK_GL(*this, Clear(GR_GL_STENCIL_BUFFER_BIT));
    116 
    117         SK_GL_RET(*this, error, GetError());
    118         GrGLenum status;
    119         SK_GL_RET(*this, status, CheckFramebufferStatus(GR_GL_FRAMEBUFFER));
    120 
    121         if (GR_GL_FRAMEBUFFER_COMPLETE != status ||
    122             GR_GL_NO_ERROR != error) {
    123             fFBO = 0;
    124             fColorBufferID = 0;
    125             fDepthStencilBufferID = 0;
    126             fGL->unref();
    127             fGL = NULL;
    128             this->destroyGLContext();
    129             return false;
    130         } else {
    131             return true;
    132         }
    133     }
    134     return false;
    135 }
    136