lab3

package cg.helloworld;

import android.app.Activity;
import android.opengl.GLSurfaceView;
import android.os.Bundle;
import android.view.WindowManager;

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import javax.microedition.khronos.opengles.GL11;

import androidx.activity.EdgeToEdge;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;


public class MainActivity extends AppCompatActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        GLSurfaceView view = new GLSurfaceView(this);
        view.setRenderer(new SquareRenderer());
        setContentView(view);
    }
}

class HelloWorldRenderer implements GLSurfaceView.Renderer {
    @Override
    public void onSurfaceCreated(GL10 gl, javax.microedition.khronos.egl.EGLConfig eglConfig) {
        gl.glClearColor(1, 0, 0, 1);
    }

    public void onSurfaceChanged(GL10 gl, int width, int height) {
        gl.glViewport(0, 0, width, height);
    }

    public void onDrawFrame(GL10 gl) {
        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
    }

}

class Square {
    private FloatBuffer mFVertexBuffer;
    private ByteBuffer mColorBuffer;
    private ByteBuffer mIndexBuffer;
    public Square() {

        float vertices[] =
                {
                        -1.0f, -1.0f,
                        1.0f, -1.0f,
                        -1.0f, 1.0f,
                        1.0f, 1.0f
                };
        byte maxColor = (byte) 255;
        byte colors[] =
                {
                        0, 0, 0, maxColor,
                        maxColor, 0, 0, maxColor,
                        0, 0, 0, maxColor,
                        maxColor, 0, 0, maxColor,
                };
        byte indices[] =
                {
                        0, 3, 1,
                        0, 2, 3
                };

        ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
        vbb.order(ByteOrder.nativeOrder());
        mFVertexBuffer = vbb.asFloatBuffer();
        mFVertexBuffer.put(vertices);
        mFVertexBuffer.position(0);
        mColorBuffer = ByteBuffer.allocateDirect(colors.length);
        mColorBuffer.put(colors);
        mColorBuffer.position(0);
        mIndexBuffer = ByteBuffer.allocateDirect(indices.length);
        mIndexBuffer.put(indices);
        mIndexBuffer.position(0);
    }
    public void draw(GL10 gl){
        gl.glFrontFace(GL11.GL_CW);
        gl.glVertexPointer(2, GL11.GL_FLOAT, 0, mFVertexBuffer);
        gl.glColorPointer(4, GL11.GL_UNSIGNED_BYTE, 0, mColorBuffer);
        gl.glDrawElements(GL11.GL_TRIANGLES, 6, GL11.GL_UNSIGNED_BYTE, mIndexBuffer);
    }
}

class SquareRenderer implements GLSurfaceView.Renderer{
    private Square mSquare;
    private float mTransY;

    public SquareRenderer(){
        mSquare = new Square();
    }

    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
        gl.glDisable(GL10.GL_DITHER);
        gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
        gl.glClearColor(0,0,0,0);
        gl.glEnable(GL10.GL_CULL_FACE);
        gl.glShadeModel(GL10.GL_SMOOTH);
        gl.glEnable(GL10.GL_DEPTH_TEST);
    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height) {
        gl.glViewport(0, 0, width, height);
        gl.glMatrixMode(GL10.GL_PROJECTION);
        gl.glLoadIdentity();
        float ratio = (float) width / height;
        gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10);
    }

    @Override
    public void onDrawFrame(GL10 gl) {
        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        gl.glMatrixMode(GL10.GL_MODELVIEW);
        gl.glLoadIdentity();
        gl.glTranslatef(0.0f,(float)Math.sin(mTransY), -3.0f);
        mTransY += 0.075f;
        gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
        gl.glEnableClientState(GL10.GL_COLOR_ARRAY);
        mSquare.draw(gl);
    }
}