1 /*
2 * Copyright 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 #include <GLES/gl.h>
18
19 #include <cutils/compiler.h>
20
21 #include "GLES10RenderEngine.h"
22
23 // ---------------------------------------------------------------------------
24 namespace android {
25 // ---------------------------------------------------------------------------
26
~GLES10RenderEngine()27 GLES10RenderEngine::~GLES10RenderEngine() {
28 }
29
setupLayerBlending(bool premultipliedAlpha,bool opaque,float alpha)30 void GLES10RenderEngine::setupLayerBlending(
31 #ifdef USE_HWC2
32 bool premultipliedAlpha, bool opaque, float alpha) {
33 #else
34 bool premultipliedAlpha, bool opaque, int alpha) {
35 #endif
36 // OpenGL ES 1.0 doesn't support texture combiners.
37 // This path doesn't properly handle opaque layers that have non-opaque
38 // alpha values. The alpha channel will be copied into the framebuffer or
39 // screenshot, so if the framebuffer or screenshot is blended on top of
40 // something else, whatever is below the window will incorrectly show
41 // through.
42 #ifdef USE_HWC2
43 if (CC_UNLIKELY(alpha < 1.0f)) {
44 if (premultipliedAlpha) {
45 glColor4f(alpha, alpha, alpha, alpha);
46 } else {
47 glColor4f(1.0f, 1.0f, 1.0f, alpha);
48 }
49 #else
50 if (CC_UNLIKELY(alpha < 0xFF)) {
51 GLfloat floatAlpha = alpha * (1.0f / 255.0f);
52 if (premultipliedAlpha) {
53 glColor4f(floatAlpha, floatAlpha, floatAlpha, floatAlpha);
54 } else {
55 glColor4f(1.0f, 1.0f, 1.0f, floatAlpha);
56 }
57 #endif
58 glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
59 } else {
60 glTexEnvx(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
61 }
62
63 #ifdef USE_HWC2
64 if (alpha < 1.0f || !opaque) {
65 #else
66 if (alpha < 0xFF || !opaque) {
67 #endif
68 glEnable(GL_BLEND);
69 glBlendFunc(premultipliedAlpha ? GL_ONE : GL_SRC_ALPHA,
70 GL_ONE_MINUS_SRC_ALPHA);
71 } else {
72 glDisable(GL_BLEND);
73 }
74 }
75
76 // ---------------------------------------------------------------------------
77 }; // namespace android
78 // ---------------------------------------------------------------------------
79