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
11SkGLContextHelper::SkGLContextHelper()
12    : fFBO(0)
13    , fColorBufferID(0)
14    , fDepthStencilBufferID(0)
15    , fGL(NULL) {
16}
17
18SkGLContextHelper::~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
30bool 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