1
2/*
3 * Copyright 2011 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/SkNativeGLContext.h"
9
10SkNativeGLContext::AutoContextRestore::AutoContextRestore() {
11    fOldEGLContext = eglGetCurrentContext();
12    fOldDisplay = eglGetCurrentDisplay();
13    fOldSurface = eglGetCurrentSurface(EGL_DRAW);
14
15}
16
17SkNativeGLContext::AutoContextRestore::~AutoContextRestore() {
18    if (NULL != fOldDisplay) {
19        eglMakeCurrent(fOldDisplay, fOldSurface, fOldSurface, fOldEGLContext);
20    }
21}
22
23///////////////////////////////////////////////////////////////////////////////
24
25SkNativeGLContext::SkNativeGLContext()
26    : fContext(EGL_NO_CONTEXT)
27    , fDisplay(EGL_NO_DISPLAY)
28    , fSurface(EGL_NO_SURFACE) {
29}
30
31SkNativeGLContext::~SkNativeGLContext() {
32    this->destroyGLContext();
33}
34
35void SkNativeGLContext::destroyGLContext() {
36    if (fDisplay) {
37        eglMakeCurrent(fDisplay, 0, 0, 0);
38
39        if (fContext) {
40            eglDestroyContext(fDisplay, fContext);
41            fContext = EGL_NO_CONTEXT;
42        }
43
44        if (fSurface) {
45            eglDestroySurface(fDisplay, fSurface);
46            fSurface = EGL_NO_SURFACE;
47        }
48
49        //TODO should we close the display?
50        fDisplay = EGL_NO_DISPLAY;
51    }
52}
53
54const GrGLInterface* SkNativeGLContext::createGLContext() {
55    static const EGLint kEGLContextAttribsForOpenGL[] = {
56        EGL_NONE
57    };
58
59    static const EGLint kEGLContextAttribsForOpenGLES[] = {
60        EGL_CONTEXT_CLIENT_VERSION, 2,
61        EGL_NONE
62    };
63
64    static const struct {
65        const EGLint* fContextAttribs;
66        EGLenum fAPI;
67        EGLint  fRenderableTypeBit;
68        GrGLStandard fStandard;
69    } kAPIs[] = {
70        {   // OpenGL
71            kEGLContextAttribsForOpenGL,
72            EGL_OPENGL_API,
73            EGL_OPENGL_BIT,
74            kGL_GrGLStandard
75        },
76        {   // OpenGL ES. This seems to work for both ES2 and 3 (when available).
77            kEGLContextAttribsForOpenGLES,
78            EGL_OPENGL_ES_API,
79            EGL_OPENGL_ES2_BIT,
80            kGLES_GrGLStandard
81        },
82    };
83
84    const GrGLInterface* interface = NULL;
85
86    for (size_t api = 0; NULL == interface && api < SK_ARRAY_COUNT(kAPIs); ++api) {
87        fDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
88
89        EGLint majorVersion;
90        EGLint minorVersion;
91        eglInitialize(fDisplay, &majorVersion, &minorVersion);
92
93#if 0
94        SkDebugf("VENDOR: %s\n", eglQueryString(fDisplay, EGL_VENDOR));
95        SkDebugf("APIS: %s\n", eglQueryString(fDisplay, EGL_CLIENT_APIS));
96        SkDebugf("VERSION: %s\n", eglQueryString(fDisplay, EGL_VERSION));
97        SkDebugf("EXTENSIONS %s\n", eglQueryString(fDisplay, EGL_EXTENSIONS));
98#endif
99
100        if (!eglBindAPI(kAPIs[api].fAPI)) {
101            continue;
102        }
103
104        EGLint numConfigs;
105        const EGLint configAttribs[] = {
106            EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
107            EGL_RENDERABLE_TYPE, kAPIs[api].fRenderableTypeBit,
108            EGL_RED_SIZE, 8,
109            EGL_GREEN_SIZE, 8,
110            EGL_BLUE_SIZE, 8,
111            EGL_ALPHA_SIZE, 8,
112            EGL_NONE
113        };
114
115        EGLConfig surfaceConfig;
116        if (!eglChooseConfig(fDisplay, configAttribs, &surfaceConfig, 1, &numConfigs)) {
117            SkDebugf("eglChooseConfig failed. EGL Error: 0x%08x\n", eglGetError());
118            continue;
119        }
120
121        fContext = eglCreateContext(fDisplay, surfaceConfig, NULL, kAPIs[api].fContextAttribs);
122        if (EGL_NO_CONTEXT == fContext) {
123            SkDebugf("eglCreateContext failed.  EGL Error: 0x%08x\n", eglGetError());
124            continue;
125        }
126
127        static const EGLint kSurfaceAttribs[] = {
128            EGL_WIDTH, 1,
129            EGL_HEIGHT, 1,
130            EGL_NONE
131        };
132
133        fSurface = eglCreatePbufferSurface(fDisplay, surfaceConfig, kSurfaceAttribs);
134        if (EGL_NO_SURFACE == fSurface) {
135            SkDebugf("eglCreatePbufferSurface failed. EGL Error: 0x%08x\n", eglGetError());
136            this->destroyGLContext();
137            continue;
138        }
139
140        if (!eglMakeCurrent(fDisplay, fSurface, fSurface, fContext)) {
141            SkDebugf("eglMakeCurrent failed.  EGL Error: 0x%08x\n", eglGetError());
142            this->destroyGLContext();
143            continue;
144        }
145
146        interface = GrGLCreateNativeInterface();
147        if (NULL == interface) {
148            SkDebugf("Failed to create gl interface.\n");
149            this->destroyGLContext();
150            continue;
151        }
152
153        if (!interface->validate()) {
154            interface->unref();
155            interface = NULL;
156            this->destroyGLContext();
157        }
158    }
159
160    return interface;
161}
162
163void SkNativeGLContext::makeCurrent() const {
164    if (!eglMakeCurrent(fDisplay, fSurface, fSurface, fContext)) {
165        SkDebugf("Could not set the context.\n");
166    }
167}
168
169void SkNativeGLContext::swapBuffers() const {
170    if (!eglSwapBuffers(fDisplay, fSurface)) {
171        SkDebugf("Could not complete eglSwapBuffers.\n");
172    }
173}
174