Mesh.java

/**
 * Copyright 2010 Per-Erik Bergman (per-erik.bergman@jayway.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alarmclocksnoozers.runnershigh;

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

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

import android.graphics.Bitmap;
import android.opengl.GLUtils;

/**
 * Mesh is a base class for 3D objects making it easier to create and maintain
 * new primitives.
 * 
 * @author Per-Erik Bergman (per-erik.bergman@jayway.com)
 * 
 */
public class Mesh {
	// Our vertex buffer.
	private FloatBuffer mVerticesBuffer = null;

	// Our index buffer.
	private ShortBuffer mIndicesBuffer = null;

	// Our UV texture buffer.
	private FloatBuffer mTextureBuffer; // New variable.

	// Our texture id.
	private int mTextureId = -1; // New variable.

	// The bitmap we want to load as a texture.
	private Bitmap mBitmap; // New variable.

	// Indicates if we need to load the texture.
	private boolean mShouldLoadTexture = false; // New variable.
	
	private int mWrapS;
	private int mWrapT;
	
	private ByteBuffer byteBuf;

	// The number of indices.
	private int mNumOfIndices = -1;

	// Flat Color
	private final float[] mRGBA = new float[] { 1.0f, 1.0f, 1.0f, 1.0f };

	// Smooth Colors
	private FloatBuffer mColorBuffer = null;

	// Translate params.
	public float x = 0;

	public float y = 0;

	public float z = 0;

	// Rotate params.
	public float rx = 0;

	public float ry = 0;

	public float rz = 0;
	
	public boolean shouldBeDrawn = true;

	/**
	 * Render the mesh.
	 * 
	 * @param gl
	 *            the OpenGL context to render to.
	 */
	public void draw(GL10 gl) {
		if (!shouldBeDrawn) return;
		
		gl.glPushMatrix();
		// Counter-clockwise winding.
		gl.glFrontFace(GL10.GL_CCW);
		// Enable face culling.
		gl.glEnable(GL10.GL_CULL_FACE);
		// What faces to remove with the face culling.
		gl.glCullFace(GL10.GL_BACK);
		// Enabled the vertices buffer for writing and to be used during
		// rendering.
		gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
		// Specifies the location and data format of an array of vertex
		// coordinates to use when rendering.
		gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mVerticesBuffer);
		// Set flat color
		gl.glColor4f(mRGBA[0], mRGBA[1], mRGBA[2], mRGBA[3]);
		// Smooth color
		if (mColorBuffer != null) {
			// Enable the color array buffer to be used during rendering.
			gl.glEnableClientState(GL10.GL_COLOR_ARRAY);
			gl.glColorPointer(4, GL10.GL_FLOAT, 0, mColorBuffer);
		}

		// New part...
		if (mShouldLoadTexture) {
			loadGLTexture(gl);
			mShouldLoadTexture = false;
		}
		if (mTextureId != -1 && mTextureBuffer != null) {
			gl.glEnable(GL10.GL_TEXTURE_2D);
			// Enable the texture state
			gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);

			// Point to our buffers
			gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, mTextureBuffer);
			gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureId);
		}
		// ... end new part.

		gl.glTranslatef(x, y, z);
		gl.glRotatef(rx, 1, 0, 0);
		gl.glRotatef(ry, 0, 1, 0);
		gl.glRotatef(rz, 0, 0, 1);

		// Point out the where the color buffer is.
		gl.glDrawElements(GL10.GL_TRIANGLES, mNumOfIndices,
				GL10.GL_UNSIGNED_SHORT, mIndicesBuffer);
		// Disable the vertices buffer.
		gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);

		// New part...
		if (mTextureId != -1 && mTextureBuffer != null) {
			gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
		}
		// ... end new part.

		// Disable face culling.
		gl.glDisable(GL10.GL_CULL_FACE);
		gl.glPopMatrix();
	}

	/**
	 * Set the vertices.
	 * 
	 * @param vertices
	 */
	protected void setVertices(float[] vertices) {
		// a float is 4 bytes, therefore we multiply the number if
		// vertices with 4.
		ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length * 4);
		vbb.order(ByteOrder.nativeOrder());
		mVerticesBuffer = vbb.asFloatBuffer();
		mVerticesBuffer.put(vertices);
		mVerticesBuffer.position(0);
	}

	/**
	 * Set the indices.
	 * 
	 * @param indices
	 */
	protected void setIndices(short[] indices) {
		// short is 2 bytes, therefore we multiply the number if
		// vertices with 2.
		ByteBuffer ibb = ByteBuffer.allocateDirect(indices.length * 2);
		ibb.order(ByteOrder.nativeOrder());
		mIndicesBuffer = ibb.asShortBuffer();
		mIndicesBuffer.put(indices);
		mIndicesBuffer.position(0);
		mNumOfIndices = indices.length;
	}

	/**
	 * Set the texture coordinates.
	 * 
	 * @param textureCoords
	 */
	protected void setTextureCoordinates(float[] textureCoords) { 
		// float is 4 bytes, therefore we multiply the number if
		// vertices with 4.
		byteBuf = ByteBuffer.allocateDirect(textureCoords.length * 4);
		byteBuf.order(ByteOrder.nativeOrder());
		mTextureBuffer = byteBuf.asFloatBuffer();
		mTextureBuffer.put(textureCoords);
		mTextureBuffer.position(0);
	}

	/**
	 * Set one flat color on the mesh.
	 * 
	 * @param red
	 * @param green
	 * @param blue
	 * @param alpha
	 */
	protected void setColor(float red, float green, float blue, float alpha) {
		mRGBA[0] = red;
		mRGBA[1] = green;
		mRGBA[2] = blue;
		mRGBA[3] = alpha;
	}

	/**
	 * Set the colors
	 * 
	 * @param colors
	 */
	protected void setColors(float[] colors) {
		// float has 4 bytes.
		ByteBuffer cbb = ByteBuffer.allocateDirect(colors.length * 4);
		cbb.order(ByteOrder.nativeOrder());
		mColorBuffer = cbb.asFloatBuffer();
		mColorBuffer.put(colors);
		mColorBuffer.position(0);
	}

	/**
	 * Set the bitmap to load into a texture.
	 * 
	 * @param bitmap
	 */
	public void loadBitmap(Bitmap bitmap) {
		this.mBitmap = bitmap;
		mShouldLoadTexture = true;
		mWrapS = GL10.GL_CLAMP_TO_EDGE;
		mWrapT = GL10.GL_CLAMP_TO_EDGE;
	}
	
	public void loadBitmap(Bitmap bitmap, int wrapS, int wrapT) {
		this.mBitmap = bitmap;
		mShouldLoadTexture = true;
		mWrapS = wrapS;
		mWrapT = wrapT;
	}

	/**
	 * Loads the texture.
	 * 
	 * @param gl
	 */
	private void loadGLTexture(GL10 gl) { // New function
		// Generate one texture pointer...
		int[] textures = new int[1];
		gl.glGenTextures(1, textures, 0);
		mTextureId = textures[0];

		gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);

		if ( gl instanceof GL11 ) {
		        gl.glTexParameterf(GL11.GL_TEXTURE_2D, GL11.GL_GENERATE_MIPMAP, GL11.GL_TRUE);
		} 
		
		// ...and bind it to our array
		gl.glBindTexture(GL10.GL_TEXTURE_2D, mTextureId);
		// Create Nearest Filtered Texture
		gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
				GL10.GL_NEAREST);
		gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER,
				GL10.GL_NEAREST);
		
		// Different possible texture parameters, e.g. GL10.GL_CLAMP_TO_EDGE
		gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
				mWrapS);
		gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
				mWrapT);

		// Use the Android GLUtils to specify a two-dimensional texture image
		// from our bitmap
		GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, mBitmap, 0);
	}
}