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
17package com.example.android.basicglsurfaceview;
18
19import java.io.IOException;
20import java.io.InputStream;
21import java.nio.ByteBuffer;
22import java.nio.ByteOrder;
23import java.nio.FloatBuffer;
24
25import javax.microedition.khronos.egl.EGLConfig;
26import javax.microedition.khronos.opengles.GL10;
27
28import android.content.Context;
29import android.graphics.Bitmap;
30import android.graphics.BitmapFactory;
31import android.opengl.GLES20;
32import android.opengl.GLSurfaceView;
33import android.opengl.GLUtils;
34import android.opengl.Matrix;
35import android.os.SystemClock;
36import android.util.Log;
37
38class GLES20TriangleRenderer implements GLSurfaceView.Renderer {
39
40    public GLES20TriangleRenderer(Context context) {
41        mContext = context;
42        mTriangleVertices = ByteBuffer.allocateDirect(mTriangleVerticesData.length
43                * FLOAT_SIZE_BYTES).order(ByteOrder.nativeOrder()).asFloatBuffer();
44        mTriangleVertices.put(mTriangleVerticesData).position(0);
45    }
46
47    public void onDrawFrame(GL10 glUnused) {
48        // Ignore the passed-in GL10 interface, and use the GLES20
49        // class's static methods instead.
50        GLES20.glClearColor(0.0f, 0.0f, 1.0f, 1.0f);
51        GLES20.glClear( GLES20.GL_DEPTH_BUFFER_BIT | GLES20.GL_COLOR_BUFFER_BIT);
52        GLES20.glUseProgram(mProgram);
53        checkGlError("glUseProgram");
54
55        GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
56        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureID);
57
58        mTriangleVertices.position(TRIANGLE_VERTICES_DATA_POS_OFFSET);
59        GLES20.glVertexAttribPointer(maPositionHandle, 3, GLES20.GL_FLOAT, false,
60                TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
61        checkGlError("glVertexAttribPointer maPosition");
62        mTriangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
63        GLES20.glEnableVertexAttribArray(maPositionHandle);
64        checkGlError("glEnableVertexAttribArray maPositionHandle");
65        GLES20.glVertexAttribPointer(maTextureHandle, 2, GLES20.GL_FLOAT, false,
66                TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);
67        checkGlError("glVertexAttribPointer maTextureHandle");
68        GLES20.glEnableVertexAttribArray(maTextureHandle);
69        checkGlError("glEnableVertexAttribArray maTextureHandle");
70
71        long time = SystemClock.uptimeMillis() % 4000L;
72        float angle = 0.090f * ((int) time);
73        Matrix.setRotateM(mMMatrix, 0, angle, 0, 0, 1.0f);
74        Matrix.multiplyMM(mMVPMatrix, 0, mVMatrix, 0, mMMatrix, 0);
75        Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mMVPMatrix, 0);
76
77        GLES20.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, mMVPMatrix, 0);
78        GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, 3);
79        checkGlError("glDrawArrays");
80    }
81
82    public void onSurfaceChanged(GL10 glUnused, int width, int height) {
83        // Ignore the passed-in GL10 interface, and use the GLES20
84        // class's static methods instead.
85        GLES20.glViewport(0, 0, width, height);
86        float ratio = (float) width / height;
87        Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7);
88    }
89
90    public void onSurfaceCreated(GL10 glUnused, EGLConfig config) {
91        // Ignore the passed-in GL10 interface, and use the GLES20
92        // class's static methods instead.
93        mProgram = createProgram(mVertexShader, mFragmentShader);
94        if (mProgram == 0) {
95            return;
96        }
97        maPositionHandle = GLES20.glGetAttribLocation(mProgram, "aPosition");
98        checkGlError("glGetAttribLocation aPosition");
99        if (maPositionHandle == -1) {
100            throw new RuntimeException("Could not get attrib location for aPosition");
101        }
102        maTextureHandle = GLES20.glGetAttribLocation(mProgram, "aTextureCoord");
103        checkGlError("glGetAttribLocation aTextureCoord");
104        if (maTextureHandle == -1) {
105            throw new RuntimeException("Could not get attrib location for aTextureCoord");
106        }
107
108        muMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
109        checkGlError("glGetUniformLocation uMVPMatrix");
110        if (muMVPMatrixHandle == -1) {
111            throw new RuntimeException("Could not get attrib location for uMVPMatrix");
112        }
113
114        /*
115         * Create our texture. This has to be done each time the
116         * surface is created.
117         */
118
119        int[] textures = new int[1];
120        GLES20.glGenTextures(1, textures, 0);
121
122        mTextureID = textures[0];
123        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureID);
124
125        GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER,
126                GLES20.GL_NEAREST);
127        GLES20.glTexParameterf(GLES20.GL_TEXTURE_2D,
128                GLES20.GL_TEXTURE_MAG_FILTER,
129                GLES20.GL_LINEAR);
130
131        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S,
132                GLES20.GL_REPEAT);
133        GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T,
134                GLES20.GL_REPEAT);
135
136        InputStream is = mContext.getResources()
137            .openRawResource(R.raw.robot);
138        Bitmap bitmap;
139        try {
140            bitmap = BitmapFactory.decodeStream(is);
141        } finally {
142            try {
143                is.close();
144            } catch(IOException e) {
145                // Ignore.
146            }
147        }
148
149        GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
150        bitmap.recycle();
151
152        Matrix.setLookAtM(mVMatrix, 0, 0, 0, -5, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
153    }
154
155    private int loadShader(int shaderType, String source) {
156        int shader = GLES20.glCreateShader(shaderType);
157        if (shader != 0) {
158            GLES20.glShaderSource(shader, source);
159            GLES20.glCompileShader(shader);
160            int[] compiled = new int[1];
161            GLES20.glGetShaderiv(shader, GLES20.GL_COMPILE_STATUS, compiled, 0);
162            if (compiled[0] == 0) {
163                Log.e(TAG, "Could not compile shader " + shaderType + ":");
164                Log.e(TAG, GLES20.glGetShaderInfoLog(shader));
165                GLES20.glDeleteShader(shader);
166                shader = 0;
167            }
168        }
169        return shader;
170    }
171
172    private int createProgram(String vertexSource, String fragmentSource) {
173        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexSource);
174        if (vertexShader == 0) {
175            return 0;
176        }
177
178        int pixelShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentSource);
179        if (pixelShader == 0) {
180            return 0;
181        }
182
183        int program = GLES20.glCreateProgram();
184        if (program != 0) {
185            GLES20.glAttachShader(program, vertexShader);
186            checkGlError("glAttachShader");
187            GLES20.glAttachShader(program, pixelShader);
188            checkGlError("glAttachShader");
189            GLES20.glLinkProgram(program);
190            int[] linkStatus = new int[1];
191            GLES20.glGetProgramiv(program, GLES20.GL_LINK_STATUS, linkStatus, 0);
192            if (linkStatus[0] != GLES20.GL_TRUE) {
193                Log.e(TAG, "Could not link program: ");
194                Log.e(TAG, GLES20.glGetProgramInfoLog(program));
195                GLES20.glDeleteProgram(program);
196                program = 0;
197            }
198        }
199        return program;
200    }
201
202    private void checkGlError(String op) {
203        int error;
204        while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) {
205            Log.e(TAG, op + ": glError " + error);
206            throw new RuntimeException(op + ": glError " + error);
207        }
208    }
209
210    private static final int FLOAT_SIZE_BYTES = 4;
211    private static final int TRIANGLE_VERTICES_DATA_STRIDE_BYTES = 5 * FLOAT_SIZE_BYTES;
212    private static final int TRIANGLE_VERTICES_DATA_POS_OFFSET = 0;
213    private static final int TRIANGLE_VERTICES_DATA_UV_OFFSET = 3;
214    private final float[] mTriangleVerticesData = {
215            // X, Y, Z, U, V
216            -1.0f, -0.5f, 0, -0.5f, 0.0f,
217            1.0f, -0.5f, 0, 1.5f, -0.0f,
218            0.0f,  1.11803399f, 0, 0.5f,  1.61803399f };
219
220    private FloatBuffer mTriangleVertices;
221
222    private final String mVertexShader =
223        "uniform mat4 uMVPMatrix;\n" +
224        "attribute vec4 aPosition;\n" +
225        "attribute vec2 aTextureCoord;\n" +
226        "varying vec2 vTextureCoord;\n" +
227        "void main() {\n" +
228        "  gl_Position = uMVPMatrix * aPosition;\n" +
229        "  vTextureCoord = aTextureCoord;\n" +
230        "}\n";
231
232    private final String mFragmentShader =
233        "precision mediump float;\n" +
234        "varying vec2 vTextureCoord;\n" +
235        "uniform sampler2D sTexture;\n" +
236        "void main() {\n" +
237        "  gl_FragColor = texture2D(sTexture, vTextureCoord);\n" +
238        "}\n";
239
240    private float[] mMVPMatrix = new float[16];
241    private float[] mProjMatrix = new float[16];
242    private float[] mMMatrix = new float[16];
243    private float[] mVMatrix = new float[16];
244
245    private int mProgram;
246    private int mTextureID;
247    private int muMVPMatrixHandle;
248    private int maPositionHandle;
249    private int maTextureHandle;
250
251    private Context mContext;
252    private static String TAG = "GLES20TriangleRenderer";
253}
254