/* * Copyright (C) 2011 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.example.android.opengl; import javax.microedition.khronos.egl.EGLConfig; import javax.microedition.khronos.opengles.GL10; import android.opengl.GLES20; import android.opengl.GLSurfaceView; import android.opengl.Matrix; import android.util.Log; /** * Provides drawing instructions for a GLSurfaceView object. This class * must override the OpenGL ES drawing lifecycle methods: * */ public class MyGLRenderer implements GLSurfaceView.Renderer { private static final String TAG = "MyGLRenderer"; private Triangle mTriangle; private Square mSquare; // mMVPMatrix is an abbreviation for "Model View Projection Matrix" private final float[] mMVPMatrix = new float[16]; private final float[] mProjectionMatrix = new float[16]; private final float[] mViewMatrix = new float[16]; private final float[] mRotationMatrix = new float[16]; private float mAngle; @Override public void onSurfaceCreated(GL10 unused, EGLConfig config) { // Set the background frame color GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f); mTriangle = new Triangle(); mSquare = new Square(); } @Override public void onDrawFrame(GL10 unused) { float[] scratch = new float[16]; // Draw background color GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT); // Set the camera position (View matrix) Matrix.setLookAtM(mViewMatrix, 0, 0, 0, -3, 0f, 0f, 0f, 0f, 1.0f, 0.0f); // Calculate the projection and view transformation Matrix.multiplyMM(mMVPMatrix, 0, mProjectionMatrix, 0, mViewMatrix, 0); // Draw square mSquare.draw(mMVPMatrix); // Create a rotation for the triangle // Use the following code to generate constant rotation. // Leave this code out when using TouchEvents. // long time = SystemClock.uptimeMillis() % 4000L; // float angle = 0.090f * ((int) time); Matrix.setRotateM(mRotationMatrix, 0, mAngle, 0, 0, 1.0f); // Combine the rotation matrix with the projection and camera view // Note that the mMVPMatrix factor *must be first* in order // for the matrix multiplication product to be correct. Matrix.multiplyMM(scratch, 0, mMVPMatrix, 0, mRotationMatrix, 0); // Draw triangle mTriangle.draw(scratch); } @Override public void onSurfaceChanged(GL10 unused, int width, int height) { // Adjust the viewport based on geometry changes, // such as screen rotation GLES20.glViewport(0, 0, width, height); float ratio = (float) width / height; // this projection matrix is applied to object coordinates // in the onDrawFrame() method Matrix.frustumM(mProjectionMatrix, 0, -ratio, ratio, -1, 1, 3, 7); } /** * Utility method for compiling a OpenGL shader. * *

Note: When developing shaders, use the checkGlError() * method to debug shader coding errors.

* * @param type - Vertex or fragment shader type. * @param shaderCode - String containing the shader code. * @return - Returns an id for the shader. */ public static int loadShader(int type, String shaderCode){ // create a vertex shader type (GLES20.GL_VERTEX_SHADER) // or a fragment shader type (GLES20.GL_FRAGMENT_SHADER) int shader = GLES20.glCreateShader(type); // add the source code to the shader and compile it GLES20.glShaderSource(shader, shaderCode); GLES20.glCompileShader(shader); return shader; } /** * Utility method for debugging OpenGL calls. Provide the name of the call * just after making it: * *
    * mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
    * MyGLRenderer.checkGlError("glGetUniformLocation");
* * If the operation is not successful, the check throws an error. * * @param glOperation - Name of the OpenGL call to check. */ public static void checkGlError(String glOperation) { int error; while ((error = GLES20.glGetError()) != GLES20.GL_NO_ERROR) { Log.e(TAG, glOperation + ": glError " + error); throw new RuntimeException(glOperation + ": glError " + error); } } /** * Returns the rotation angle of the triangle shape (mTriangle). * * @return - A float representing the rotation angle. */ public float getAngle() { return mAngle; } /** * Sets the rotation angle of the triangle shape (mTriangle). */ public void setAngle(float angle) { mAngle = angle; } }