android怎么繪制三維坐標(biāo)

小億
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2024-01-18 14:03:32

在Android中，可以使用OpenGL ES來(lái)繪制三維坐標(biāo)。下面是一個(gè)簡(jiǎn)單的示例代碼：

首先，在AndroidManifest.xml文件中添加以下權(quán)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創(chuàng)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 = {
                // 坐標(biāo)順序：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,

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