ProgramCache.cpp revision 892f22dcb96927b4a4f9ab7badd6f2c9f4f37c1f 
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 <GLES2/gl2.h>
18#include <GLES2/gl2ext.h>
19
20#include <utils/String8.h>
21
22#include "ProgramCache.h"
23#include "Program.h"
24#include "Description.h"
25
26namespace android {
27// -----------------------------------------------------------------------------------------------
28
29
30/*
31 * A simple formatter class to automatically add the endl and
32 * manage the indentation.
33 */
34
35class Formatter;
36static Formatter& indent(Formatter& f);
37static Formatter& dedent(Formatter& f);
38
39class Formatter {
40    String8 mString;
41    int mIndent;
42    typedef Formatter& (*FormaterManipFunc)(Formatter&);
43    friend Formatter& indent(Formatter& f);
44    friend Formatter& dedent(Formatter& f);
45public:
46    Formatter() : mIndent(0) {}
47
48    String8 getString() const {
49        return mString;
50    }
51
52    friend Formatter& operator << (Formatter& out, const char* in) {
53        for (int i=0 ; i<out.mIndent ; i++) {
54            out.mString.append("    ");
55        }
56        out.mString.append(in);
57        out.mString.append("\n");
58        return out;
59    }
60    friend inline Formatter& operator << (Formatter& out, const String8& in) {
61        return operator << (out, in.string());
62    }
63    friend inline Formatter& operator<<(Formatter& to, FormaterManipFunc func) {
64        return (*func)(to);
65    }
66};
67Formatter& indent(Formatter& f) {
68    f.mIndent++;
69    return f;
70}
71Formatter& dedent(Formatter& f) {
72    f.mIndent--;
73    return f;
74}
75
76// -----------------------------------------------------------------------------------------------
77
78ANDROID_SINGLETON_STATIC_INSTANCE(ProgramCache)
79
80
81ProgramCache::ProgramCache() {
82}
83
84ProgramCache::~ProgramCache() {
85}
86
87ProgramCache::Key ProgramCache::computeKey(const Description& description) {
88    Key needs;
89    needs.set(Key::TEXTURE_MASK,
90            (description.mTextureTarget == GL_TEXTURE_EXTERNAL_OES) ? Key::TEXTURE_EXT :
91            (description.mTextureTarget == GL_TEXTURE_2D)           ? Key::TEXTURE_2D :
92            Key::TEXTURE_OFF)
93    .set(Key::PLANE_ALPHA_MASK,
94            (description.mPlaneAlpha < 1) ? Key::PLANE_ALPHA_LT_ONE : Key::PLANE_ALPHA_EQ_ONE)
95    .set(Key::BLEND_MASK,
96            description.mPremultipliedAlpha ? Key::BLEND_PREMULT : Key::BLEND_NORMAL)
97    .set(Key::OPACITY_MASK,
98            description.mOpaque ? Key::OPACITY_OPAQUE : Key::OPACITY_TRANSLUCENT);
99    return needs;
100}
101
102String8 ProgramCache::generateVertexShader(const Key& needs) {
103    Formatter vs;
104    if (needs.isTexturing()) {
105        vs  << "attribute vec4 texCoords;"
106            << "varying vec2 outTexCoords;";
107    }
108    vs << "attribute vec4 position;"
109       << "uniform mat4 projection;"
110       << "uniform mat4 texture;"
111       << "void main(void) {" << indent
112       << "gl_Position = projection * position;";
113    if (needs.isTexturing()) {
114        vs << "outTexCoords = (texture * texCoords).st;";
115    }
116    vs << dedent << "}";
117    return vs.getString();
118}
119
120String8 ProgramCache::generateFragmentShader(const Key& needs) {
121    Formatter fs;
122    if (needs.getTextureTarget() == Key::TEXTURE_EXT) {
123        fs << "#extension GL_OES_EGL_image_external : require";
124    }
125    if (needs.getTextureTarget() == Key::TEXTURE_EXT) {
126        fs << "uniform samplerExternalOES sampler;"
127           << "varying vec2 outTexCoords;";
128    } else if (needs.getTextureTarget() == Key::TEXTURE_2D) {
129        fs << "uniform sampler2D sampler;"
130           << "varying vec2 outTexCoords;";
131    } else if (needs.getTextureTarget() == Key::TEXTURE_OFF) {
132        fs << "uniform vec4 color;";
133    }
134    if (needs.hasPlaneAlpha()) {
135        fs << "uniform float alphaPlane;";
136    }
137    fs << "void main(void) {" << indent;
138    if (needs.isTexturing()) {
139        fs << "gl_FragColor = texture2D(sampler, outTexCoords);";
140    } else {
141        fs << "gl_FragColor = color;";
142    }
143    if (needs.hasPlaneAlpha()) {
144        // modulate the alpha value with planeAlpha
145        if (needs.isPremultiplied()) {
146            // ... and the color too if we're premultiplied
147            if (needs.isOpaque()) {
148                // ... we're opaque, only premultiply the color component
149                fs << "gl_FragColor.rgb *= alphaPlane;"
150                   << "gl_FragColor.a = alphaPlane;";
151            } else {
152                fs << "gl_FragColor *= alphaPlane;";
153            }
154        } else {
155            // not premultiplied
156            if (needs.isOpaque()) {
157                fs << "gl_FragColor.a = alphaPlane;";
158            } else {
159                fs << "gl_FragColor.a *= alphaPlane;";
160            }
161        }
162    } else {
163        if (needs.isOpaque()) {
164            fs << "gl_FragColor.a = 1.0;";
165        }
166    }
167    fs << dedent << "}";
168    return fs.getString();
169}
170
171Program* ProgramCache::generateProgram(const Key& needs) {
172    // vertex shader
173    String8 vs = generateVertexShader(needs);
174
175    // fragment shader
176    String8 fs = generateFragmentShader(needs);
177
178    Program* program = new Program(needs, vs.string(), fs.string());
179    return program;
180}
181
182void ProgramCache::useProgram(const Description& description) {
183
184    // generate the key for the shader based on the description
185    Key needs(computeKey(description));
186
187     // look-up the program in the cache
188    Program* program = mCache.valueFor(needs);
189    if (program == NULL) {
190        // we didn't find our program, so generate one...
191        nsecs_t time = -systemTime();
192        program = generateProgram(needs);
193        mCache.add(needs, program);
194        time += systemTime();
195
196        //ALOGD(">>> generated new program: needs=%08X, time=%u ms (%d programs)",
197        //        needs.mNeeds, uint32_t(ns2ms(time)), mCache.size());
198    }
199
200    // here we have a suitable program for this description
201    if (program->isValid()) {
202        program->use();
203        program->setUniforms(description);
204    }
205}
206
207
208} /* namespace android */
209