glcube.java

android 下学习openGL的一个不错demo

/***
 * Excerpted from "Hello, Android!",
 * published by The Pragmatic Bookshelf.
 * Copyrights apply to this code. It may not be used to create training material, 
 * courses, books, articles, and the like. Contact us if you are in doubt.
 * We make no guarantees that this code is fit for any purpose. 
 * Visit http://www.pragmaticprogrammer.com/titles/eband for more book information.
***/

package com.mot.opengl;

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

import javax.microedition.khronos.opengles.GL;
import javax.microedition.khronos.opengles.GL10;
import javax.microedition.khronos.opengles.GL11;
import javax.microedition.khronos.opengles.GL11Ext;
import javax.microedition.khronos.opengles.GL11ExtensionPack;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.widget.Toast;

public class GLCube {
   private final IntBuffer mVertexBuffer;
   
   
   private final IntBuffer mTextureBuffer;

   private static int[] textures = new int[6];

   
   public GLCube() {
      
      int one = 65536;
      int half = one / 2;
      int vertices[] = { 
            // FRONT
            -half, -half, half, half, -half, half,
            -half, half, half, half, half, half,
            // BACK
            -half, -half, -half, -half, half, -half,
            half, -half, -half, half, half, -half,
            // LEFT
            -half, -half, half, -half, half, half,
            -half, -half, -half, -half, half, -half,
            // RIGHT
            half, -half, -half, half, half, -half,
            half, -half, half, half, half, half,
            // TOP
            -half, half, half, half, half, half,
            -half, half, -half, half, half, -half,
            // BOTTOM
            -half, -half, half, -half, -half, -half,
            half, -half, half, half, -half, -half, };
      

      
      int texCoords[] = {
            // FRONT
            0, one, one, one, 0, 0, one, 0,
            // BACK
            one, one, one, 0, 0, one, 0, 0,
            // LEFT
            one, one, one, 0, 0, one, 0, 0,
            // RIGHT
            one, one, one, 0, 0, one, 0, 0,
            // TOP
            one, 0, 0, 0, one, one, 0, one,
            // BOTTOM
            0, 0, 0, one, one, 0, one, one, };
      

      
      // Buffers to be passed to gl*Pointer() functions must be
      // direct, i.e., they must be placed on the native heap
      // where the garbage collector cannot move them.
      //
      // Buffers with multi-byte data types (e.g., short, int,
      // float) must have their byte order set to native order
      ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
      vbb.order(ByteOrder.nativeOrder());
      mVertexBuffer = vbb.asIntBuffer();
      mVertexBuffer.put(vertices);
      mVertexBuffer.position(0);
      

      
      // ...
      ByteBuffer tbb = ByteBuffer.allocateDirect(texCoords.length * 4);
      tbb.order(ByteOrder.nativeOrder());
      mTextureBuffer = tbb.asIntBuffer();
      mTextureBuffer.put(texCoords);
      mTextureBuffer.position(0);
      
   }
   

   public void draw(GL10 gl) { 

	      //Bind diffirent face
	   /*
	      gl.glBindTexture(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_POSITIVE_X, textures[0]); //
	      gl.glBindTexture(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_POSITIVE_Y, textures[1]); //
	      gl.glBindTexture(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_POSITIVE_Z, textures[2]); //
	      gl.glBindTexture(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_NEGATIVE_X, textures[3]); //
	      gl.glBindTexture(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, textures[4]); //
	      gl.glBindTexture(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_POSITIVE_Z, textures[5]); //
	     */
	  gl.glTexCoordPointer(2, GL10.GL_FIXED, 0, mTextureBuffer);
	  gl.glVertexPointer(3, GL10.GL_FIXED, 0, mVertexBuffer);

      gl.glColor4f(1, 1, 1, 1);
	  gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]); //
      gl.glNormal3f(0, 0, 1);
      gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, 4);
	  gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[1]); //
      gl.glNormal3f(0, 0, -1);
      gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 4, 4);

      gl.glColor4f(1, 1, 1, 1);
	  gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[2]); //
      gl.glNormal3f(-1, 0, 0);
      gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 8, 4);
	  gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[3]); //
      gl.glNormal3f(1, 0, 0);
      gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 12, 4);

      gl.glColor4f(1, 1, 1, 1);
	  gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[4]); //
      gl.glNormal3f(0, 1, 0);
      gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 16, 4);
	  gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[5]); //
      gl.glNormal3f(0, -1, 0);
      gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 20, 4);
      
      
   }
   
   

   public static ByteBuffer extract(Bitmap bmp) { 
      ByteBuffer bb = ByteBuffer.allocateDirect(bmp.getHeight()
            * bmp.getWidth() * 4);
      bb.order(ByteOrder.BIG_ENDIAN);
      IntBuffer ib = bb.asIntBuffer();

      // Convert ARGB -> RGBA
      for (int y = bmp.getHeight() - 1; y > -1; y--)
         for (int x = 0; x < bmp.getWidth(); x++) {
            int pix = bmp.getPixel(x, bmp.getHeight() - y - 1);
            // int alpha = ((pix >> 24) & 0xFF);
            int red = ((pix >> 16) & 0xFF);
            int green = ((pix >> 8) & 0xFF);
            int blue = ((pix) & 0xFF);

            // Make up alpha for interesting effect
            ib.put(red << 24 | green << 16 | blue << 8
                  | ((red + blue + green) / 3));
         }
      bb.position(0);
      return bb;
   }

   public static void loadTexture(GL10 gl, Context context, int[] resource) {
	   
	   /*
	   int[] cube_face = {
			   
			   GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_POSITIVE_X,
			   GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_POSITIVE_Y,
			   GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_POSITIVE_Z,
			   GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_NEGATIVE_X,
			   GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_NEGATIVE_Y,
			   GL11ExtensionPack.GL_TEXTURE_CUBE_MAP_NEGATIVE_Z
			   
	   };
	   
	   int len = resource.length;
	   ByteBuffer[] bb = new ByteBuffer[len];
	   
	   int[] tmp_tex = new int[1];
	   gl.glGenTextures(1, tmp_tex, 0);
	   int tex = tmp_tex[0];

	   int i;
	   for ( i=0; i<len; i++ ) {
		   
		   Bitmap bmp = BitmapFactory.decodeResource(
		            context.getResources(), resource[i]);

		   bb[i] = extract(bmp);
	   }
	   
	   int width = 128;
	   int height = 128;
	      

	   // Load it up
	      gl.glBindTexture(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP, tex);
	      
	      
		   gl.glTexParameterx(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP, 
				   GL10.GL_TEXTURE_WRAP_S, GL10.GL_CLAMP_TO_EDGE);
		   gl.glTexParameterx(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP, 
				   GL10.GL_TEXTURE_WRAP_T, GL10.GL_CLAMP_TO_EDGE);
		   //gl.glTexParameterx(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP, 
		//		   GL10.GL_TEXTURE_WRAP_R, GL10.GL_CLAMP_TO_EDGE);
		   gl.glTexParameterx(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP, 
				   GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
		   gl.glTexParameterx(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP, 
				   GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_LINEAR_MIPMAP_LINEAR);
		   gl.glTexParameterx(GL11ExtensionPack.GL_TEXTURE_CUBE_MAP, 
				   GL11.GL_GENERATE_MIPMAP, GL10.GL_TRUE);
		   
		   for ( i=0; i<len; i++ ) {
			   
			      gl.glTexImage2D(cube_face[i], 0, GL10.GL_RGBA,
				            width, height, 0, GL10.GL_RGBA,
				            GL10.GL_UNSIGNED_BYTE, bb[i]);
		   }
		   */
		   
	   int len = resource.length;
	   ByteBuffer[] bb = new ByteBuffer[len];
		   
	   int i;
	   for ( i=0; i<len; i++ ) {
		   
		   Bitmap bmp = BitmapFactory.decodeResource(
		            context.getResources(), resource[i]);

		   bb[i] = extract(bmp);
	   }
	   

		   int width = 128;
		   int height = 128;
		   
		   for (i=0;i<6;i++) {
			   gl.glGenTextures(1, textures, i);
			   //gl.glGenTextures(1, tmp_tex, i);
		      gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[i]);
		      gl.glTexParameterx(GL10.GL_TEXTURE_2D,
		            GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_LINEAR);
		      gl.glTexParameterx(GL10.GL_TEXTURE_2D,
		            GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
		      gl.glTexImage2D(GL10.GL_TEXTURE_2D, 0, GL10.GL_RGBA,
			            width, height, 0, GL10.GL_RGBA,
			            GL10.GL_UNSIGNED_BYTE, bb[i]);
		   }
		    
		}
}