/*
* 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 android.opengl.Matrix;
import javax.microedition.khronos.opengles.GL10;
/**
* A utility that projects
*
*/
class Projector {
public Projector() {
mMVP = new float[16];
mV = new float[4];
mGrabber = new MatrixGrabber();
}
public void setCurrentView(int x, int y, int width, int height) {
mX = x;
mY = y;
mViewWidth = width;
mViewHeight = height;
}
public void project(float[] obj, int objOffset, float[] win, int winOffset) {
if (!mMVPComputed) {
Matrix.multiplyMM(mMVP, 0, mGrabber.mProjection, 0, mGrabber.mModelView, 0);
mMVPComputed = true;
}
Matrix.multiplyMV(mV, 0, mMVP, 0, obj, objOffset);
float rw = 1.0f / mV[3];
win[winOffset] = mX + mViewWidth * (mV[0] * rw + 1.0f) * 0.5f;
win[winOffset + 1] = mY + mViewHeight * (mV[1] * rw + 1.0f) * 0.5f;
win[winOffset + 2] = (mV[2] * rw + 1.0f) * 0.5f;
}
/**
* Get the current projection matrix. Has the side-effect of
* setting current matrix mode to GL_PROJECTION
* @param gl
*/
public void getCurrentProjection(GL10 gl) {
mGrabber.getCurrentProjection(gl);
mMVPComputed = false;
}
/**
* Get the current model view matrix. Has the side-effect of
* setting current matrix mode to GL_MODELVIEW
* @param gl
*/
public void getCurrentModelView(GL10 gl) {
mGrabber.getCurrentModelView(gl);
mMVPComputed = false;
}
private MatrixGrabber mGrabber;
private boolean mMVPComputed;
private float[] mMVP;
private float[] mV;
private int mX;
private int mY;
private int mViewWidth;
private int mViewHeight;
}