com_android_server_AssetAtlasService.cpp revision 18b4cbeedef21c1fa666a110a157bab66edff976 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "AssetAtlasService"
18
19#include "jni.h"
20#include "JNIHelp.h"
21
22#include <android_view_GraphicBuffer.h>
23#include <cutils/log.h>
24
25#include <GLES2/gl2.h>
26#include <GLES2/gl2ext.h>
27
28#include <EGL/egl.h>
29#include <EGL/eglext.h>
30
31#include <SkCanvas.h>
32#include <SkBitmap.h>
33
34namespace android {
35
36// ----------------------------------------------------------------------------
37// Defines
38// ----------------------------------------------------------------------------
39
40// Defines how long to wait for the GPU when uploading the atlas
41// This timeout is defined in nanoseconds (see EGL_KHR_fence_sync extension)
42#define FENCE_TIMEOUT 2000000000
43
44// ----------------------------------------------------------------------------
45// JNI Helpers
46// ----------------------------------------------------------------------------
47
48static struct {
49    jfieldID mFinalizer;
50    jfieldID mNativeCanvas;
51} gCanvasClassInfo;
52
53static struct {
54    jfieldID mNativeCanvas;
55} gCanvasFinalizerClassInfo;
56
57#define GET_LONG(object, field) \
58    env->GetLongField(object, field)
59
60#define SET_LONG(object, field, value) \
61    env->SetLongField(object, field, value)
62
63// ----------------------------------------------------------------------------
64// Canvas management
65// ----------------------------------------------------------------------------
66
67static inline void swapCanvasPtr(JNIEnv* env, jobject canvasObj, SkCanvas* newCanvas) {
68    jobject canvasFinalizerObj = env->GetObjectField(canvasObj, gCanvasClassInfo.mFinalizer);
69    SkCanvas* previousCanvas = reinterpret_cast<SkCanvas*>(
70            GET_LONG(canvasObj, gCanvasClassInfo.mNativeCanvas));
71    SET_LONG(canvasObj, gCanvasClassInfo.mNativeCanvas, (long) newCanvas);
72    SET_LONG(canvasFinalizerObj, gCanvasFinalizerClassInfo.mNativeCanvas, (long) newCanvas);
73    SkSafeUnref(previousCanvas);
74}
75
76static SkBitmap* com_android_server_AssetAtlasService_acquireCanvas(JNIEnv* env, jobject,
77        jobject canvas, jint width, jint height) {
78
79    SkBitmap* bitmap = new SkBitmap;
80    bitmap->setConfig(SkBitmap::kARGB_8888_Config, width, height);
81    bitmap->allocPixels();
82    bitmap->eraseColor(0);
83
84    SkCanvas* nativeCanvas = SkNEW_ARGS(SkCanvas, (*bitmap));
85    swapCanvasPtr(env, canvas, nativeCanvas);
86
87    return bitmap;
88}
89
90static void com_android_server_AssetAtlasService_releaseCanvas(JNIEnv* env, jobject,
91        jobject canvas, SkBitmap* bitmap) {
92
93    SkCanvas* nativeCanvas = SkNEW(SkCanvas);
94    swapCanvasPtr(env, canvas, nativeCanvas);
95
96    delete bitmap;
97}
98
99#define CLEANUP_GL_AND_RETURN(result) \
100    if (fence != EGL_NO_SYNC_KHR) eglDestroySyncKHR(display, fence); \
101    if (image) eglDestroyImageKHR(display, image); \
102    if (texture) glDeleteTextures(1, &texture); \
103    if (surface != EGL_NO_SURFACE) eglDestroySurface(display, surface); \
104    if (context != EGL_NO_CONTEXT) eglDestroyContext(display, context); \
105    eglMakeCurrent(display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT); \
106    eglReleaseThread(); \
107    eglTerminate(display); \
108    return result;
109
110static jboolean com_android_server_AssetAtlasService_upload(JNIEnv* env, jobject,
111        jobject graphicBuffer, SkBitmap* bitmap) {
112
113    // The goal of this method is to copy the bitmap into the GraphicBuffer
114    // using the GPU to swizzle the texture content
115    sp<GraphicBuffer> buffer(graphicBufferForJavaObject(env, graphicBuffer));
116
117    if (buffer != NULL) {
118        EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);
119        if (display == EGL_NO_DISPLAY) return false;
120
121        EGLint major;
122        EGLint minor;
123        if (!eglInitialize(display, &major, &minor)) {
124            ALOGW("Could not initialize EGL");
125            return false;
126        }
127
128        // We're going to use a 1x1 pbuffer surface later on
129        // The configuration doesn't really matter for what we're trying to do
130        EGLint configAttrs[] = {
131                EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
132                EGL_RED_SIZE, 8,
133                EGL_GREEN_SIZE, 8,
134                EGL_BLUE_SIZE, 8,
135                EGL_ALPHA_SIZE, 0,
136                EGL_DEPTH_SIZE, 0,
137                EGL_STENCIL_SIZE, 0,
138                EGL_NONE
139        };
140        EGLConfig configs[1];
141        EGLint configCount;
142        if (!eglChooseConfig(display, configAttrs, configs, 1, &configCount)) {
143            ALOGW("Could not select EGL configuration");
144            eglReleaseThread();
145            eglTerminate(display);
146            return false;
147        }
148        if (configCount <= 0) {
149            ALOGW("Could not find EGL configuration");
150            eglReleaseThread();
151            eglTerminate(display);
152            return false;
153        }
154
155        // These objects are initialized below but the default "null"
156        // values are used to cleanup properly at any point in the
157        // initialization sequence
158        GLuint texture = 0;
159        EGLImageKHR image = EGL_NO_IMAGE_KHR;
160        EGLSurface surface = EGL_NO_SURFACE;
161        EGLSyncKHR fence = EGL_NO_SYNC_KHR;
162
163        EGLint attrs[] = { EGL_CONTEXT_CLIENT_VERSION, 2, EGL_NONE };
164        EGLContext context = eglCreateContext(display, configs[0], EGL_NO_CONTEXT, attrs);
165        if (context == EGL_NO_CONTEXT) {
166            ALOGW("Could not create EGL context");
167            CLEANUP_GL_AND_RETURN(false);
168        }
169
170        // Create the 1x1 pbuffer
171        EGLint surfaceAttrs[] = { EGL_WIDTH, 1, EGL_HEIGHT, 1, EGL_NONE };
172        surface = eglCreatePbufferSurface(display, configs[0], surfaceAttrs);
173        if (surface == EGL_NO_SURFACE) {
174            ALOGW("Could not create EGL surface");
175            CLEANUP_GL_AND_RETURN(false);
176        }
177
178        if (!eglMakeCurrent(display, surface, surface, context)) {
179            ALOGW("Could not change current EGL context");
180            CLEANUP_GL_AND_RETURN(false);
181        }
182
183        // We use an EGLImage to access the content of the GraphicBuffer
184        // The EGL image is later bound to a 2D texture
185        EGLClientBuffer clientBuffer = (EGLClientBuffer) buffer->getNativeBuffer();
186        EGLint imageAttrs[] = { EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE };
187        image = eglCreateImageKHR(display, EGL_NO_CONTEXT,
188                EGL_NATIVE_BUFFER_ANDROID, clientBuffer, imageAttrs);
189        if (image == EGL_NO_IMAGE_KHR) {
190            ALOGW("Could not create EGL image");
191            CLEANUP_GL_AND_RETURN(false);
192        }
193
194        glGenTextures(1, &texture);
195        glBindTexture(GL_TEXTURE_2D, texture);
196        glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, image);
197        if (glGetError() != GL_NO_ERROR) {
198            ALOGW("Could not create/bind texture");
199            CLEANUP_GL_AND_RETURN(false);
200        }
201
202        // Upload the content of the bitmap in the GraphicBuffer
203        glPixelStorei(GL_UNPACK_ALIGNMENT, bitmap->bytesPerPixel());
204        glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, bitmap->width(), bitmap->height(),
205                GL_RGBA, GL_UNSIGNED_BYTE, bitmap->getPixels());
206        if (glGetError() != GL_NO_ERROR) {
207            ALOGW("Could not upload to texture");
208            CLEANUP_GL_AND_RETURN(false);
209        }
210
211        // The fence is used to wait for the texture upload to finish
212        // properly. We cannot rely on glFlush() and glFinish() as
213        // some drivers completely ignore these API calls
214        fence = eglCreateSyncKHR(display, EGL_SYNC_FENCE_KHR, NULL);
215        if (fence == EGL_NO_SYNC_KHR) {
216            ALOGW("Could not create sync fence %#x", eglGetError());
217            CLEANUP_GL_AND_RETURN(false);
218        }
219
220        // The flag EGL_SYNC_FLUSH_COMMANDS_BIT_KHR will trigger a
221        // pipeline flush (similar to what a glFlush() would do.)
222        EGLint waitStatus = eglClientWaitSyncKHR(display, fence,
223                EGL_SYNC_FLUSH_COMMANDS_BIT_KHR, FENCE_TIMEOUT);
224        if (waitStatus != EGL_CONDITION_SATISFIED_KHR) {
225            ALOGW("Failed to wait for the fence %#x", eglGetError());
226            CLEANUP_GL_AND_RETURN(false);
227        }
228
229        CLEANUP_GL_AND_RETURN(true);
230    }
231
232    return false;
233}
234
235// ----------------------------------------------------------------------------
236// JNI Glue
237// ----------------------------------------------------------------------------
238
239#define FIND_CLASS(var, className) \
240        var = env->FindClass(className); \
241        LOG_FATAL_IF(! var, "Unable to find class " className);
242
243#define GET_FIELD_ID(var, clazz, fieldName, fieldDescriptor) \
244        var = env->GetFieldID(clazz, fieldName, fieldDescriptor); \
245        LOG_FATAL_IF(! var, "Unable to find field " fieldName);
246
247const char* const kClassPathName = "com/android/server/AssetAtlasService";
248
249static JNINativeMethod gMethods[] = {
250    { "nAcquireAtlasCanvas", "(Landroid/graphics/Canvas;II)I",
251            (void*) com_android_server_AssetAtlasService_acquireCanvas },
252    { "nReleaseAtlasCanvas", "(Landroid/graphics/Canvas;I)V",
253            (void*) com_android_server_AssetAtlasService_releaseCanvas },
254    { "nUploadAtlas", "(Landroid/view/GraphicBuffer;I)Z",
255            (void*) com_android_server_AssetAtlasService_upload },
256};
257
258int register_android_server_AssetAtlasService(JNIEnv* env) {
259    jclass clazz;
260
261    FIND_CLASS(clazz, "android/graphics/Canvas");
262    GET_FIELD_ID(gCanvasClassInfo.mFinalizer, clazz, "mFinalizer",
263            "Landroid/graphics/Canvas$CanvasFinalizer;");
264    GET_FIELD_ID(gCanvasClassInfo.mNativeCanvas, clazz, "mNativeCanvas", "J");
265
266    FIND_CLASS(clazz, "android/graphics/Canvas$CanvasFinalizer");
267    GET_FIELD_ID(gCanvasFinalizerClassInfo.mNativeCanvas, clazz, "mNativeCanvas", "J");
268
269    return jniRegisterNativeMethods(env, kClassPathName, gMethods, NELEM(gMethods));
270}
271
272};
273