LayerScreenshot.cpp revision a2f4e56fec0fb36c4a370eb23d6e9dc57f250b59 
1/*
2 * Copyright (C) 2011 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#include <stdlib.h>
18#include <stdint.h>
19#include <sys/types.h>
20
21#include <utils/Errors.h>
22#include <utils/Log.h>
23
24#include <ui/GraphicBuffer.h>
25
26#include "LayerScreenshot.h"
27#include "SurfaceFlinger.h"
28#include "DisplayHardware/DisplayHardware.h"
29
30
31namespace android {
32// ---------------------------------------------------------------------------
33
34LayerScreenshot::LayerScreenshot(SurfaceFlinger* flinger, DisplayID display,
35        const sp<Client>& client)
36    : LayerBaseClient(flinger, display, client),
37      mTextureName(0), mFlinger(flinger)
38{
39}
40
41LayerScreenshot::~LayerScreenshot()
42{
43    if (mTextureName) {
44        mFlinger->postMessageAsync(
45                new SurfaceFlinger::MessageDestroyGLTexture(mTextureName) );
46    }
47}
48
49status_t LayerScreenshot::captureLocked() {
50    GLfloat u, v;
51    status_t result = mFlinger->renderScreenToTextureLocked(0, &mTextureName, &u, &v);
52    if (result != NO_ERROR) {
53        return result;
54    }
55    initTexture(u, v);
56    return NO_ERROR;
57}
58
59status_t LayerScreenshot::capture() {
60    GLfloat u, v;
61    status_t result = mFlinger->renderScreenToTexture(0, &mTextureName, &u, &v);
62    if (result != NO_ERROR) {
63        return result;
64    }
65    initTexture(u, v);
66    return NO_ERROR;
67}
68
69void LayerScreenshot::initTexture(GLfloat u, GLfloat v) {
70    glBindTexture(GL_TEXTURE_2D, mTextureName);
71    glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
72    glTexParameterx(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
73    mTexCoords[0] = 0;         mTexCoords[1] = v;
74    mTexCoords[2] = 0;         mTexCoords[3] = 0;
75    mTexCoords[4] = u;         mTexCoords[5] = 0;
76    mTexCoords[6] = u;         mTexCoords[7] = v;
77}
78
79void LayerScreenshot::initStates(uint32_t w, uint32_t h, uint32_t flags) {
80    LayerBaseClient::initStates(w, h, flags);
81    if (!(flags & ISurfaceComposer::eHidden)) {
82        capture();
83    }
84}
85
86uint32_t LayerScreenshot::doTransaction(uint32_t flags)
87{
88    const Layer::State& draw(drawingState());
89    const Layer::State& curr(currentState());
90
91    if (draw.flags & ISurfaceComposer::eLayerHidden) {
92        if (!(curr.flags & ISurfaceComposer::eLayerHidden)) {
93            // we're going from hidden to visible
94            status_t err = captureLocked();
95            if (err != NO_ERROR) {
96                ALOGW("createScreenshotSurface failed (%s)", strerror(-err));
97            }
98        }
99    } else if (curr.flags & ISurfaceComposer::eLayerHidden) {
100        // we're going from visible to hidden
101        if (mTextureName) {
102            glDeleteTextures(1, &mTextureName);
103            mTextureName = 0;
104        }
105    }
106    return LayerBaseClient::doTransaction(flags);
107}
108
109void LayerScreenshot::onDraw(const Region& clip) const
110{
111    const State& s(drawingState());
112    Region::const_iterator it = clip.begin();
113    Region::const_iterator const end = clip.end();
114    if (s.alpha>0 && (it != end)) {
115        const DisplayHardware& hw(graphicPlane(0).displayHardware());
116        const GLfloat alpha = s.alpha/255.0f;
117        const uint32_t fbHeight = hw.getHeight();
118
119        if (s.alpha == 0xFF) {
120            glDisable(GL_BLEND);
121        } else {
122            glEnable(GL_BLEND);
123            glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
124        }
125
126        glColor4f(0, 0, 0, alpha);
127
128        glDisable(GL_TEXTURE_EXTERNAL_OES);
129        glEnable(GL_TEXTURE_2D);
130
131        glBindTexture(GL_TEXTURE_2D, mTextureName);
132        glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
133        glMatrixMode(GL_TEXTURE);
134        glLoadIdentity();
135        glMatrixMode(GL_MODELVIEW);
136
137        glEnableClientState(GL_TEXTURE_COORD_ARRAY);
138        glTexCoordPointer(2, GL_FLOAT, 0, mTexCoords);
139        glVertexPointer(2, GL_FLOAT, 0, mVertices);
140
141        while (it != end) {
142            const Rect& r = *it++;
143            const GLint sy = fbHeight - (r.top + r.height());
144            glScissor(r.left, sy, r.width(), r.height());
145            glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
146        }
147
148        glDisable(GL_BLEND);
149        glDisable(GL_TEXTURE_2D);
150        glDisableClientState(GL_TEXTURE_COORD_ARRAY);
151    }
152}
153
154// ---------------------------------------------------------------------------
155
156}; // namespace android
157