OpenGLUtils.java

package com.tid.opengljava;

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

import javax.microedition.khronos.opengles.GL10;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.BitmapFactory.Options;
import android.opengl.GLUtils;
import android.util.Log;

public class OpenGLUtils {

	public static FloatBuffer allocateFloatBuffer(int capacity){
		ByteBuffer vbb = ByteBuffer.allocateDirect(capacity);
        vbb.order(ByteOrder.nativeOrder());
        return vbb.asFloatBuffer();
	}
	
	public static IntBuffer allocateInttBuffer(int capacity){
		ByteBuffer vbb = ByteBuffer.allocateDirect(capacity);
        vbb.order(ByteOrder.nativeOrder());
        return vbb.asIntBuffer();
	}
	
	public static ShortBuffer allocateShortBuffer(int capacity){
		ByteBuffer vbb = ByteBuffer.allocateDirect(capacity);
        vbb.order(ByteOrder.nativeOrder());
        return vbb.asShortBuffer();
	}
	
	public static void addVertex3f(FloatBuffer buffer,float x,float y,float z){
		buffer.put(x);
		buffer.put(y);
		buffer.put(z);
	}
	
	public static void addIndex(ShortBuffer buffer,int index1,int index2,int index3){
		buffer.put((short) index1);
		buffer.put((short) index2);
		buffer.put((short) index3);
	}
	
	public static void addCoord2f(FloatBuffer buffer,float x,float y){
		buffer.put(x);
		buffer.put(y);
	}
	
	public static void addColorf(FloatBuffer buffer,float r,float g,float b,float a){
		buffer.put(r);
		buffer.put(g);
		buffer.put(b);
		buffer.put(a);
	}

	public static FloatBuffer toFloatBufferPositionZero(float[] values) {
		ByteBuffer vbb = ByteBuffer.allocateDirect(values.length*4);
        vbb.order(ByteOrder.nativeOrder());
        FloatBuffer buffer=vbb.asFloatBuffer();
        buffer.put(values);
        buffer.position(0);
		return buffer;
	}
	
	public static ShortBuffer toShortBuffer(short[] values) {
		ByteBuffer vbb = ByteBuffer.allocateDirect(values.length*2);
        vbb.order(ByteOrder.nativeOrder());
        ShortBuffer buffer=vbb.asShortBuffer();
        buffer.put(values);
        buffer.position(0);
		return buffer;
	}
	
	
	public static Bitmap loadBitmap(Context mContext,int id){
		Options opt=new Options();
		Bitmap bitmap= BitmapFactory.decodeResource(mContext.getResources(), id,opt);	
		
		System.out.println(bitmap.getConfig());
		if(!sizeCheck(bitmap)){
			throw new RuntimeException("width or height not 2x size,it make invalid error on OpenGL:"+id);
		}
		return bitmap;
	}
	private static boolean sizeCheck(Bitmap bitmap){
		boolean ret=true;
		int t=2;
		int w=bitmap.getWidth();
		
		while(w!=t){
			if(w%t==1){
				Log.e("glutils w=",w+","+t);
				return false;
			}
			t*=2;
			if(t>w){
				return false;
			}
		}
		
		t=2;
		int h=bitmap.getHeight();
		while(h!=t){
			if(h%t==1){
				Log.e("glutils h=",h+","+t);
				return false;
			}
			t*=2;
			if(t>h){
				return false;
			}
		}
		
		return ret;
	}
	
	/**
	 * this is for  resized
	 * GLU.gluOrtho2D (gl,-1f, 1.0f, -1f, 1.0f);
	 * @param x
	 * @param y
	 * @param screenWidth
	 * @param screenHeight
	 * @return
	 */
	public static float[] toOpenGLCordinate(float x,float y,int screenWidth,int screenHeight){
		float sx=((float)x/screenWidth)*2-1.0f;
    	float sy=((float)y/screenHeight)*2-1.0f;
    	sy*=-1;
    	return new float[]{sx,sy};
	}
	
	/*
	 * y should *=-1;
	 */
	public static float toOpenGLCordinate(float x,int screenWidth){
		Log.i("myapp","x="+x+","+screenWidth);
		float sx=((float)x/screenWidth)*2-1.0f;
    	return sx;
	}
	
	
	public static float realToVirtialValue(int x,int real,float virtial){
    	return virtial/real*x;
	}
	
	public static int virtualToRealvalue(float x,int real,float virtial){
		//using DecimalFormat make gc
    	return (int) ((float)x/(virtial/real));
	}
	
	
	private static FloatBuffer mTextureBuffer;
	private static FloatBuffer mFVertexBuffer;
	private static ShortBuffer mIndexBuffer;
	
	public static FloatBuffer getBoxTriangleTextureBuffer(){
		if(mTextureBuffer==null){
			mTextureBuffer=OpenGLUtils.allocateFloatBuffer(4*6*2);
			OpenGLUtils.addCoord2f(mTextureBuffer,0.0f, 1.0f); 
			OpenGLUtils.addCoord2f(mTextureBuffer,0.0f, 0.0f); 
			OpenGLUtils.addCoord2f(mTextureBuffer,1.0f, 1.0f); 
			OpenGLUtils.addCoord2f(mTextureBuffer,1.0f, 1.0f); 
		    OpenGLUtils.addCoord2f(mTextureBuffer,1.0f, 0.0f); 
		    OpenGLUtils.addCoord2f(mTextureBuffer,0.0f, 0.0f); 
		    mTextureBuffer.position(0);
		}
		return mTextureBuffer;
	}
	
	
	public static FloatBuffer getBoxTriangleFlipVerticalTextureBuffer(){
		if(mTextureBuffer==null){
			mTextureBuffer=OpenGLUtils.allocateFloatBuffer(4*6*2);
			OpenGLUtils.addCoord2f(mTextureBuffer,0.0f, 0.0f); 
			OpenGLUtils.addCoord2f(mTextureBuffer,0.0f, 1.0f); 
			OpenGLUtils.addCoord2f(mTextureBuffer,1.0f, 0.0f); 
			OpenGLUtils.addCoord2f(mTextureBuffer,1.0f, 0.0f); 
		    OpenGLUtils.addCoord2f(mTextureBuffer,1.0f, 1.0f); 
		    OpenGLUtils.addCoord2f(mTextureBuffer,0.0f, 1.0f); 
		    mTextureBuffer.position(0);
		}
		return mTextureBuffer;
	}
	
	public static FloatBuffer getBoxTextureBuffer(){
		if(mTextureBuffer==null){
			mTextureBuffer=OpenGLUtils.allocateFloatBuffer(4*4*2);
			OpenGLUtils.addCoord2f(mTextureBuffer,0.0f, 0.0f); 
			OpenGLUtils.addCoord2f(mTextureBuffer,0.0f, 1.0f); 
			OpenGLUtils.addCoord2f(mTextureBuffer,1.0f, 0.0f); 
		    OpenGLUtils.addCoord2f(mTextureBuffer,1.0f, 1.0f); 
		    mTextureBuffer.position(0);
		}
		return mTextureBuffer;
	}
	public static ShortBuffer getBoxIndexBuffer(){
		if(mIndexBuffer==null){
			mIndexBuffer=OpenGLUtils.allocateShortBuffer(6*2);
        mIndexBuffer.put((short)0);
        mIndexBuffer.put((short)1);
        mIndexBuffer.put((short)2);
        mIndexBuffer.put((short)2);
        mIndexBuffer.put((short)3);
        mIndexBuffer.put((short)1);
        mIndexBuffer.position(0);
		}
		return mIndexBuffer;
	}
	public static FloatBuffer getBoxVertexBuffer(){
		if(mFVertexBuffer==null){
			mFVertexBuffer=OpenGLUtils.allocateFloatBuffer(4*4*3);
		    OpenGLUtils.addVertex3f(mFVertexBuffer, -1,-1f,0);
	        OpenGLUtils.addVertex3f(mFVertexBuffer, -1,1f,0);
	        
	        
	        OpenGLUtils.addVertex3f(mFVertexBuffer, 1,-1f,0);
	        OpenGLUtils.addVertex3f(mFVertexBuffer, 1,1f,0);  
	        mFVertexBuffer.position(0);
	        
		}
		return mFVertexBuffer;
	}
	
	
	public static FloatBuffer getBoxTriangleVertexBuffer(){
		if(mFVertexBuffer==null){
			mFVertexBuffer=OpenGLUtils.allocateFloatBuffer(4*6*3);
			OpenGLUtils.addVertex3f(mFVertexBuffer, -1,-1f,0);
	        OpenGLUtils.addVertex3f(mFVertexBuffer, -1,1f,0);
	        OpenGLUtils.addVertex3f(mFVertexBuffer, 1,-1f,0);
	       
	        OpenGLUtils.addVertex3f(mFVertexBuffer, 1,-1f,0);
	        OpenGLUtils.addVertex3f(mFVertexBuffer, 1,1f,0); 
	        OpenGLUtils.addVertex3f(mFVertexBuffer, -1,1f,0);
	        
	        mFVertexBuffer.position(0);
	        
		}
		return mFVertexBuffer;
	}
	
	//TODO その他のパラメターをサポート
	/*
	 * bitmapは自動で回収されます。
	 */
	public static void bindTextureImage(GL10 gl,final int id,final Bitmap bitmap){
		   gl.glBindTexture(GL10.GL_TEXTURE_2D,  id);
	       gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_CLAMP_TO_EDGE);
		   gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_CLAMP_TO_EDGE);
		   gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_NEAREST);
		   gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
		  GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
		  bitmap.recycle();
	}
	
}