package zui.polsl.pl.lab5przyklad;

import android.opengl.GLSurfaceView;
import android.opengl.GLU;

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

import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import static java.lang.Math.*;


public class MyRenderer implements GLSurfaceView.Renderer
{
    private float kat = 0;
    private float aspect = 0;
    int vertexCount = 360;
    float radius = 0.1f;
    float v = 0.02f;
    float center_x = 0.0f;
    float center_y = 0.0f;
    boolean block = false;



    @Override
    public void onSurfaceCreated(GL10 gl, EGLConfig config)
    {

    }

    @Override
    public void onSurfaceChanged(GL10 gl, int width, int height)
    {
        aspect = width/height*1.8f;
        gl.glViewport(0, 0, width, height);
        gl.glMatrixMode(GL10.GL_PROJECTION);
        gl.glLoadIdentity();
        GLU.gluPerspective(gl,45.0f,(float)width/(float)height,-1.0f, -10.0f);
        gl.glClearColor(0.0f, 1.0f, 0.0f, 1.0f);
    }

    @Override
    public void onDrawFrame(GL10 gl)
    {
        //float wierzcholki[] = {
        //        -1.0f, 0.0f, -1.0f,
        //        0.0f, 1.0f, -1.0f,
        //        1.0f, 0.0f, -1.0f
        //};

        if(center_x >= 0.9f){
            block = true;
        }
        if(center_x <= -0.9f){
            block = false;
        }
        if(block){
            center_x -= v;
        }else{
            center_x += v;
        }

        float buffer[] = new float[vertexCount*2];
        int index = 0;
        buffer[index++] = center_x;
        buffer[index++] = center_y;


        float percent, rad, outer_x, outer_y;
        int outerVertexCount = vertexCount - 1;
        for(int i = 0; i < outerVertexCount; i++){
            percent = (i / (float)(outerVertexCount - 1));
            rad = (float)(percent * 2 * Math.PI);

            outer_x = (float)(center_x + radius * cos(rad));
            outer_y = (float)((center_y + radius * sin(rad)) * aspect);

            buffer[index++] = outer_x;
            buffer[index++] = outer_y;
        }

        ByteBuffer bufor = ByteBuffer.allocateDirect(vertexCount*3*4);
        bufor.order(ByteOrder.nativeOrder());
        FloatBuffer bufor_wierzcholkow = bufor.asFloatBuffer();
        bufor_wierzcholkow.put(buffer);
        bufor_wierzcholkow.position(0);
        gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
        gl.glColor4f(0.0f, 0.0f, 1.0f, 1.0f);
        gl.glLoadIdentity();
        //gl.glRotatef(kat++, 0.0f, 0.0f, 1.0f);
        gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
        gl.glVertexPointer(2, GL10.GL_FLOAT, 0, bufor_wierzcholkow);
        //gl.glDrawArrays(GL10.GL_TRIANGLES, 0, 3);
        gl.glDrawArrays(GL10.GL_TRIANGLE_FAN, 0, vertexCount);

        gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
    }
}