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 (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(GrGLStandard forcedGpuAPI) {
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    size_t apiLimit = SK_ARRAY_COUNT(kAPIs);
85    size_t api = 0;
86    if (forcedGpuAPI == kGL_GrGLStandard) {
87        apiLimit = 1;
88    } else if (forcedGpuAPI == kGLES_GrGLStandard) {
89        api = 1;
90    }
91    SkASSERT(forcedGpuAPI == kNone_GrGLStandard || kAPIs[api].fStandard == forcedGpuAPI);
92
93    const GrGLInterface* interface = NULL;
94
95    for (; NULL == interface && api < apiLimit; ++api) {
96        fDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
97
98        EGLint majorVersion;
99        EGLint minorVersion;
100        eglInitialize(fDisplay, &majorVersion, &minorVersion);
101
102#if 0
103        SkDebugf("VENDOR: %s\n", eglQueryString(fDisplay, EGL_VENDOR));
104        SkDebugf("APIS: %s\n", eglQueryString(fDisplay, EGL_CLIENT_APIS));
105        SkDebugf("VERSION: %s\n", eglQueryString(fDisplay, EGL_VERSION));
106        SkDebugf("EXTENSIONS %s\n", eglQueryString(fDisplay, EGL_EXTENSIONS));
107#endif
108
109        if (!eglBindAPI(kAPIs[api].fAPI)) {
110            continue;
111        }
112
113        EGLint numConfigs;
114        const EGLint configAttribs[] = {
115            EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
116            EGL_RENDERABLE_TYPE, kAPIs[api].fRenderableTypeBit,
117            EGL_RED_SIZE, 8,
118            EGL_GREEN_SIZE, 8,
119            EGL_BLUE_SIZE, 8,
120            EGL_ALPHA_SIZE, 8,
121            EGL_NONE
122        };
123
124        EGLConfig surfaceConfig;
125        if (!eglChooseConfig(fDisplay, configAttribs, &surfaceConfig, 1, &numConfigs)) {
126            SkDebugf("eglChooseConfig failed. EGL Error: 0x%08x\n", eglGetError());
127            continue;
128        }
129
130        fContext = eglCreateContext(fDisplay, surfaceConfig, NULL, kAPIs[api].fContextAttribs);
131        if (EGL_NO_CONTEXT == fContext) {
132            SkDebugf("eglCreateContext failed.  EGL Error: 0x%08x\n", eglGetError());
133            continue;
134        }
135
136        static const EGLint kSurfaceAttribs[] = {
137            EGL_WIDTH, 1,
138            EGL_HEIGHT, 1,
139            EGL_NONE
140        };
141
142        fSurface = eglCreatePbufferSurface(fDisplay, surfaceConfig, kSurfaceAttribs);
143        if (EGL_NO_SURFACE == fSurface) {
144            SkDebugf("eglCreatePbufferSurface failed. EGL Error: 0x%08x\n", eglGetError());
145            this->destroyGLContext();
146            continue;
147        }
148
149        if (!eglMakeCurrent(fDisplay, fSurface, fSurface, fContext)) {
150            SkDebugf("eglMakeCurrent failed.  EGL Error: 0x%08x\n", eglGetError());
151            this->destroyGLContext();
152            continue;
153        }
154
155        interface = GrGLCreateNativeInterface();
156        if (NULL == interface) {
157            SkDebugf("Failed to create gl interface.\n");
158            this->destroyGLContext();
159            continue;
160        }
161
162        if (!interface->validate()) {
163            interface->unref();
164            interface = NULL;
165            this->destroyGLContext();
166        }
167    }
168
169    return interface;
170}
171
172void SkNativeGLContext::makeCurrent() const {
173    if (!eglMakeCurrent(fDisplay, fSurface, fSurface, fContext)) {
174        SkDebugf("Could not set the context.\n");
175    }
176}
177
178void SkNativeGLContext::swapBuffers() const {
179    if (!eglSwapBuffers(fDisplay, fSurface)) {
180        SkDebugf("Could not complete eglSwapBuffers.\n");
181    }
182}
183