/* * Copyright (C) 2007 The Android Open Source Project * * 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.example.android.apis.graphics.spritetext;import java.nio.CharBuffer;import java.nio.FloatBuffer;import javax.microedition.khronos.opengles.GL10;/** * A 2D rectangular mesh. Can be drawn textured or untextured. * */class Grid {	public Grid(int w, int h) {		if (w < 0 || w >= 65536) {			throw new IllegalArgumentException("w");		}		if (h < 0 || h >= 65536) {			throw new IllegalArgumentException("h");		}		if (w * h >= 65536) {			throw new IllegalArgumentException("w * h >= 65536");		}		mW = w;		mH = h;		int size = w * h;		mVertexArray = new float[size * 3];		mVertexBuffer = FloatBuffer.wrap(mVertexArray);		mTexCoordArray = new float[size * 2];		mTexCoordBuffer = FloatBuffer.wrap(mTexCoordArray);		int quadW = mW - 1;		int quadH = mH - 1;		int quadCount = quadW * quadH;		int indexCount = quadCount * 6;		mIndexCount = indexCount;		char[] indexArray = new char[indexCount];		/*		 * Initialize triangle list mesh.		 *		 *     [0]-----[  1] ...		 *      |    /   |		 *      |   /    |		 *      |  /     |		 *     [w]-----[w+1] ...		 *      |       |		 *		 */		{			int i = 0;			for (int y = 0; y < quadH; y++) {				for (int x = 0; x < quadW; x++) {					char a = (char) (y * mW + x);					char b = (char) (y * mW + x + 1);					char c = (char) ((y + 1) * mW + x);					char d = (char) ((y + 1) * mW + x + 1);					indexArray[i++] = a;					indexArray[i++] = b;					indexArray[i++] = c;					indexArray[i++] = b;					indexArray[i++] = c;					indexArray[i++] = d;				}			}		}		mIndexBuffer = CharBuffer.wrap(indexArray);	}	void set(int i, int j, float x, float y, float z, float u, float v) {		if (i < 0 || i >= mW) {			throw new IllegalArgumentException("i");		}		if (j < 0 || j >= mH) {			throw new IllegalArgumentException("j");		}		int index = mW * j + i;		int posIndex = index * 3;		mVertexArray[posIndex] = x;		mVertexArray[posIndex + 1] = y;		mVertexArray[posIndex + 2] = z;		int texIndex = index * 2;		mTexCoordArray[texIndex] = u;		mTexCoordArray[texIndex + 1] = v;	}	public void draw(GL10 gl, boolean useTexture) {		gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);		gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mVertexBuffer);		if (useTexture) {			gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);			gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, mTexCoordBuffer);			gl.glEnable(GL10.GL_TEXTURE_2D);		} else {			gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);			gl.glDisable(GL10.GL_TEXTURE_2D);		}		gl.glDrawElements(GL10.GL_TRIANGLES, mIndexCount,				GL10.GL_UNSIGNED_SHORT, mIndexBuffer);        gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);	}	private FloatBuffer mVertexBuffer;	private float[] mVertexArray;	private FloatBuffer mTexCoordBuffer;	private float[] mTexCoordArray;	private CharBuffer mIndexBuffer;	private int mW;	private int mH;	private int mIndexCount;}