Android 3D 游戏教程

package com.droidnova.android.games.vortex; import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.nio.FloatBuffer; import java.nio.ShortBuffer; import javax.microedition.khronos.egl.EGLConfig; import javax.microedition.khronos.opengles.GL10; import android.opengl.GLSurfaceView; import android.util.Log; public class VortexRenderer implements GLSurfaceView.Renderer { private static final String LOG_TAG = VortexRenderer.class.getSimpleName(); // a raw buffer to hold indices allowing a reuse of points. private ShortBuffer _indexBuffer; // a raw buffer to hold the vertices private FloatBuffer _vertexBuffer; // a raw buffer to hold the colors private FloatBuffer _colorBuffer; private int _nrOfVertices = 0; private float _xAngle; private float _yAngle; private float _width = 320f; private float _height = 480f; @Override public void onSurfaceCreated(GL10 gl, EGLConfig config) { // preparation Log.i(LOG_TAG, "onSurfaceCreated()"); gl.glMatrixMode(GL10.GL_PROJECTION); float size = .01f * (float) Math.tan(Math.toRadians(45.0) / 2); float ratio = _width / _height; // perspective: gl.glFrustumf(-size, size, -size / ratio, size / ratio, 0.01f, 100.0f); // orthographic: //gl.glOrthof(-1, 1, -1 / ratio, 1 / ratio, 0.01f, 100.0f); gl.glViewport(0, 0, (int) _width, (int) _height); gl.glMatrixMode(GL10.GL_MODELVIEW); gl.glEnable(GL10.GL_DEPTH_TEST); // define the color we want to be displayed as the "clipping wall" gl.glClearColor(0f, 0f, 0f, 1.0f); // enable the differentiation of which side may be visible gl.glEnable(GL10.GL_CULL_FACE); // which is the front? the one which is drawn counter clockwise gl.glFrontFace(GL10.GL_CCW); // which one should NOT be drawn gl.glCullFace(GL10.GL_BACK); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_COLOR_ARRAY); initTriangle(); } @Override public void onSurfaceChanged(GL10 gl, int w, int h) { Log.i(LOG_TAG, "onSurfaceChanged()"); _width = w; _height = h; gl.glViewport(0, 0, w, h); } public void setXAngle(float angle) { _xAngle = angle; } public float getXAngle() { return _xAngle; } public void setYAngle(float angle) { _yAngle = angle; } public float getYAngle() { return _yAngle; } @Override public void onDrawFrame(GL10 gl) { // clear the color buffer and the depth buffer gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT); gl.glVertexPointer(3, GL10.GL_FLOAT, 0, _vertexBuffer); gl.glColorPointer(4, GL10.GL_FLOAT, 0, _colorBuffer); for (int i = 1; i <= 10; i++) { gl.glLoadIdentity(); gl.glTranslatef(0.0f, -1f, -1.0f + -1.5f * i); // set rotation gl.glRotatef(-_xAngle, 1f, 0f, 0f); gl.glRotatef(-_yAngle, 0f, 1f, 0f); gl.glDrawElements(GL10.GL_TRIANGLES, _nrOfVertices, GL10.GL_UNSIGNED_SHORT, _indexBuffer); } } private void initTriangle() { float[] coords = { -0.5f, -0.5f, 0.5f, // 0 0.5f, -0.5f, 0.5f, // 1 0f, -0.5f, -0.5f, // 2 0f, 0.5f, 0f, // 3 }; _nrOfVertices = coords.length; float[] colors = { 1f, 0f, 0f, 1f, // point 0 red 0f, 1f, 0f, 1f, // point 1 green 0f, 0f, 1f, 1f, // point 2 blue 1f, 1f, 1f, 1f, // point 3 white }; short[] indices = new short[] { 0, 1, 3, // rwg 0, 2, 1, // rbg 0, 3, 2, // rbw 1, 2, 3, // bwg }; // float has 4 bytes, coordinate * 4 bytes ByteBuffer vbb = ByteBuffer.allocateDirect(coords.length * 4); vbb.order(ByteOrder.nativeOrder()); _vertexBuffer = vbb.asFloatBuffer(); // short has 2 bytes, indices * 2 bytes ByteBuffer ibb = ByteBuffer.allocateDirect(indices.length * 2); ibb.order(ByteOrder.nativeOrder()); _indexBuffer = ibb.asShortBuffer(); // float has 4 bytes, colors (RGBA) * 4 bytes ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length * 4); cbb.order(ByteOrder.nativeOrder()); _colorBuffer = cbb.asFloatBuffer(); _vertexBuffer.put(coords); _indexBuffer.put(indices); _colorBuffer.put(colors); _vertexBuffer.position(0); _indexBuffer.position(0); _colorBuffer.position(0); } }