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/*
* 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.ByteBuffer;
import java.nio.ByteOrder;
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;
final int FLOAT_SIZE = 4;
final int CHAR_SIZE = 2;
mVertexBuffer = ByteBuffer.allocateDirect(FLOAT_SIZE * size * 3)
.order(ByteOrder.nativeOrder()).asFloatBuffer();
mTexCoordBuffer = ByteBuffer.allocateDirect(FLOAT_SIZE * size * 2)
.order(ByteOrder.nativeOrder()).asFloatBuffer();
int quadW = mW - 1;
int quadH = mH - 1;
int quadCount = quadW * quadH;
int indexCount = quadCount * 6;
mIndexCount = indexCount;
mIndexBuffer = ByteBuffer.allocateDirect(CHAR_SIZE * indexCount)
.order(ByteOrder.nativeOrder()).asCharBuffer();
/*
* 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);
mIndexBuffer.put(i++, a);
mIndexBuffer.put(i++, b);
mIndexBuffer.put(i++, c);
mIndexBuffer.put(i++, b);
mIndexBuffer.put(i++, c);
mIndexBuffer.put(i++, d);
}
}
}
}
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;
mVertexBuffer.put(posIndex, x);
mVertexBuffer.put(posIndex + 1, y);
mVertexBuffer.put(posIndex + 2, z);
int texIndex = index * 2;
mTexCoordBuffer.put(texIndex, u);
mTexCoordBuffer.put(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 FloatBuffer mTexCoordBuffer;
private CharBuffer mIndexBuffer;
private int mW;
private int mH;
private int mIndexCount;
}
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