在Android中,可以使用OpenGL ES来绘制三维坐标。下面是一个简单的示例代码:
首先,在AndroidManifest.xml文件中添加以下权限:
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-feature android:glEsVersion="0x00020000" android:required="true" />
然后,在Android的Activity中使用GLSurfaceView创建OpenGL的上下文。
import android.app.Activity;
import android.content.Context;
import android.opengl.GLES20;
import android.opengl.GLSurfaceView;
import android.opengl.Matrix;
import android.os.Bundle;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
public class MainActivity extends Activity {
private GLSurfaceView mGLView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mGLView = new MyGLSurfaceView(this);
setContentView(mGLView);
}
class MyGLSurfaceView extends GLSurfaceView {
private final MyGLRenderer mRenderer;
public MyGLSurfaceView(Context context) {
super(context);
setEGLContextClientVersion(2);
mRenderer = new MyGLRenderer();
setRenderer(mRenderer);
}
}
class MyGLRenderer implements GLSurfaceView.Renderer {
private Triangle mTriangle;
@Override
public void onSurfaceCreated(GL10 unused, EGLConfig config) {
GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
mTriangle = new Triangle();
}
@Override
public void onSurfaceChanged(GL10 unused, int width, int height) {
GLES20.glViewport(0, 0, width, height);
}
@Override
public void onDrawFrame(GL10 unused) {
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
mTriangle.draw();
}
}
class Triangle {
private final String vertexShaderCode =
"uniform mat4 uMVPMatrix;" +
"attribute vec4 vPosition;" +
"void main() {" +
" gl_Position = uMVPMatrix * vPosition;" +
"}";
private final String fragmentShaderCode =
"precision mediump float;" +
"uniform vec4 vColor;" +
"void main() {" +
" gl_FragColor = vColor;" +
"}";
private final float[] triangleCoords = {
// 坐标顺序:x, y, z
0.0f, 1.0f, 0.0f,
-1.0f, -1.0f, 0.0f,
1.0f, -1.0f, 0.0f
};
private final int mProgram;
private int mPositionHandle;
private int mColorHandle;
private int mMVPMatrixHandle;
private final int vertexCount = triangleCoords.length / COORDS_PER_VERTEX;
private final int vertexStride = COORDS_PER_VERTEX * 4;
private final int COORDS_PER_VERTEX = 3;
private final int COLOR_COMPONENTS_COUNT = 4;
private final float[] color = {0.63671875f, 0.76953125f, 0.22265625f, 1.0f};
private final float[] mMVPMatrix = new float[16];
public Triangle() {
int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);
mProgram = GLES20.glCreateProgram();
GLES20.glAttachShader(mProgram, vertexShader);
GLES20.glAttachShader(mProgram, fragmentShader);
GLES20.glLinkProgram(mProgram);
Matrix.setIdentityM(mMVPMatrix, 0);
Matrix.translateM(mMVPMatrix, 0, 0, 0, -3f);
}
public void draw() {
GLES20.glUseProgram(mProgram);
mPositionHandle = GLES20.glGetAttribLocation(mProgram, "vPosition");
GLES20.glEnableVertexAttribArray(mPositionHandle);
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);
mColorHandle = GLES20.glGetUniformLocation(mProgram, "vColor");
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
mMVPMatrixHandle = GLES20.glGetUniformLocation(mProgram, "uMVPMatrix");
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false,