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copied!<p>draw a line and circle in opengl es 2.0 in android using touch event in surfaceview..</p> <pre><code> Program for Draw Line using touchEvent. when you touch two times, it will draw one line.. @Override public boolean onTouchEvent(MotionEvent ev) { switch (ev.getAction()) { case MotionEvent.ACTION_DOWN: Log.v("hari", "action down working"); if (count == 1) { dx = ev.getX(); dy = ev.getY(); dx = (dx / (getWidth() / 2)) - 1; dy = 1 - (dy / (getHeight() / 2)); Log.i("hari", "line1:" + dx + "," + dy); firstX = dx; firstY = dy; } else if (count == 2) { ux = ev.getX(); uy = ev.getY(); ux = (ux / (getWidth() / 2)) - 1; uy = 1 - (uy / (getHeight() / 2)); Log.i("hari", "line2:" + ux + "," + uy); secondX = ux; secondY = uy; myRenderer.dx = firstX; myRenderer.dy = firstY; myRenderer.ux = secondX; myRenderer.uy = secondY; requestRender(); count = 0; } break; } ---------------------------------------------------------------------------------------------- My Renderer Program : package com.example.ibus; import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.nio.FloatBuffer; import javax.microedition.khronos.egl.EGLConfig; import javax.microedition.khronos.opengles.GL10; import android.opengl.GLES20; import android.opengl.GLSurfaceView.Renderer; import android.util.Log; public class MyRenderer implements Renderer { MainActivity main; MyGLsurfaceview myGlsurface; public volatile boolean myline, mycircle, mydashedline , mysnaptoedge , snapBoolean ; public volatile double angle,length; public volatile float dlsx, dlsy, dlex, dley, dlsx1, dlsy1, dlex1, dley1, dltx, dlty, len; public volatile double rad, dlrad; int n, i; Lines line; Circle circle; Snap snapedge; // Declare as volatile because we are updating it from another thread public volatile float dx, dy, ux, uy, Dist, centerX,centerY,firstX,firstY, secondX,secondY, sex, sey; private float sx, sy, fx, fy, tx, ty; private double radian, rradian; public MyRenderer(MainActivity mainActivity, MyGLsurfaceview myGlsurfaceView) { Log.i("JO", "MyRenderer"); main = mainActivity; myGlsurface = myGlsurfaceView; } @Override public void onDrawFrame(GL10 gl) { Log.i("JO", "onDrawFrame"); // line.draw(x,y); Log.i("JO", "onDrawFrame:DX:"+dx+",DY:"+dy+",UX:"+ux+",UY:"+uy); // Draw background color GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT); //GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT | GLES20.GL_DEPTH_BUFFER_BIT); if(myline){ line.draw(dx,dy,ux,uy); } } @Override public void onSurfaceChanged(GL10 gl, int width, int height) { Log.i("JO", "onSurfaceChanged"); // Adjust the viewport based on geometry changes, // such as screen rotation GLES20.glViewport(0, 0, width, height); } @Override public void onSurfaceCreated(GL10 gl, EGLConfig config) { Log.i("JO", "onSurfaceCreated"); // Set the background frame color GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f); line = new Lines(); } 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; } } class Lines { final String vertexShaderCode = "attribute vec4 vPosition;" + "void main() {" + " gl_Position = vPosition;" + "}"; final String fragmentShaderCode = "precision mediump float;" + "uniform vec4 vColor;" + "void main() {" + " gl_FragColor = vColor;" + "}"; final FloatBuffer vertexBuffer; final int mProgram; int mPositionHandle; int mColorHandle; // number of coordinates per vertex in this array final int COORDS_PER_VERTEX = 3; float lineCoords[] = new float[6]; final int vertexCount = lineCoords.length / COORDS_PER_VERTEX; final int vertexStride = COORDS_PER_VERTEX * 4; // bytes per vertex // Set color with red, green, blue and alpha (opacity) values float color[] = { 0.63671875f, 0.76953125f, 0.22265625f, 1.0f }; public Lines() { // initialize vertex byte buffer for shape coordinates ByteBuffer bb = ByteBuffer.allocateDirect( // (number of coordinate values * 4 bytes per float) lineCoords.length * 4); // use the device hardware's native byte order bb.order(ByteOrder.nativeOrder()); // create a floating point buffer from the ByteBuffer vertexBuffer = bb.asFloatBuffer(); // prepare shaders and OpenGL program int vertexShader = MyRenderer.loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode); int fragmentShader = MyRenderer.loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode); mProgram = GLES20.glCreateProgram(); // create empty OpenGL Program GLES20.glAttachShader(mProgram, vertexShader); // add the vertex shader // to program GLES20.glAttachShader(mProgram, fragmentShader); // add the fragment // shader to program GLES20.glLinkProgram(mProgram); // create OpenGL program executables } public void draw(float dX,float dY,float uX,float uY) { lineCoords[0] = dX; lineCoords[1] = dY; lineCoords[2] = 0.0f; lineCoords[3] = uX; lineCoords[4] = uY; lineCoords[5] = 0.0f; vertexBuffer.put(lineCoords); vertexBuffer.position(0); // Add program to OpenGL environment GLES20.glUseProgram(mProgram); // get handle to vertex shader's vPosition member mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition"); // Enable a handle to the triangle vertices GLES20.glEnableVertexAttribArray(mPositionHandle); // Prepare the triangle coordinate data GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer); // get handle to fragment shader's vColor member mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor"); // Set color for drawing the triangle GLES20.glUniform4fv(mColorHandle, 1, color, 0); // Draw the triangle GLES20.glDrawArrays(GLES20.GL_LINES, 0, vertexCount); // Disable vertex array GLES20.glDisableVertexAttribArray(mPositionHandle); } } } ---------------------------------------------------------------------------------------------- </code></pre>

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