标签：android opengl android渲染 opengl es opengl glsurfaceview
使对象根据预设的程序进行运动，比如旋转三角形，可以吸引人的注意力。但是如果你想让用户同你的OpenGL ES图形进行交互会怎么样呢？使你的OpenGL ES应用程序触摸互动的关键是要扩展GLSurfaceView，复写onTouchEvent()方法，来监听touch事件。本教程展示了，如何监听透出事件，让用户旋转一个OpenGL ES对象。private final float TOUCH_SCALE_FACTOR = 180.0f / 320;
private float mPreviousX;
private float mPreviousY;
@Override
public boolean onTouchEvent(MotionEvent e) {
// MotionEvent reports input details from the touch screen
// and other input controls. In this case, you are only
// interested in events where the touch position changed.
float x = e.getX();
float y = e.getY();
switch (e.getAction()) {
case MotionEvent.ACTION_MOVE:
float dx = x - mPreviousX;
float dy = y - mPreviousY;
// reverse direction of rotation above the mid-line
if (y > getHeight() / 2) {
dx = dx * -1 ;
}
// reverse direction of rotation to left of the mid-line
if (x < getWidth() / 2) {
dy = dy * -1 ;
}
mRenderer.setAngle(
mRenderer.getAngle() +
((dx + dy) * TOUCH_SCALE_FACTOR));
requestRender();
}
mPreviousX = x;
mPreviousY = y;
return true;
}
public MyGLSurfaceView(Context context) {
...
// Render the view only when there is a change in the drawing data
setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
}
public class MyGLRenderer implements GLSurfaceView.Renderer {
...
public volatile float mAngle;
public float getAngle() {
return mAngle;
}
public void setAngle(float angle) {
mAngle = angle;
}
}
public void onDrawFrame(GL10 gl) {
...
float[] scratch = new float[16];
// Create a rotation for the triangle
// 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);
}
当你完成了上面描述的步骤，执行代码，就可以在屏幕上拖动手指来旋转这个三角形了。
原文地址 ： http://developer.android.com/training/graphics/opengl/touch.html#angle
Android OpenGL ES绘图教程之六 ：响应触摸事件
标签：android opengl android渲染 opengl es opengl glsurfaceview
原文地址：http://blog.csdn.net/fanfanxiaozu/article/details/45204037
