com.sun.prism.image.ViewPort Maven / Gradle / Ivy
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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*/
package com.sun.prism.image;
/*
* Class ViewPort represents a portion of the Image being rendered
* expressed in texture pixel coordinates, where the whole image is
* [0..Image.getWidth()]x[0..Image.getHeight()]
*/
public class ViewPort {
public float u0, v0, u1, v1;
public ViewPort(float u, float v, float du, float dv) {
u0 = u; u1 = u + du;
v0 = v; v1 = v + dv;
}
public ViewPort getScaledVersion(float pixelScale) {
if (pixelScale == 1.0f) {
return this;
}
float newu0 = u0 * pixelScale;
float newv0 = v0 * pixelScale;
float newu1 = u1 * pixelScale;
float newv1 = v1 * pixelScale;
return new ViewPort(newu0, newv0, newu1 - newu0, newv1 - newv0);
}
/*
* This methods calculate linear fuctions RelX(u) and RelY(v)
* defined as follows:
* RelX(u0) = 0; RelX(u1) = 1;
* RelY(v0) = 0; RelY(v1) = 1;
* which maps source : [u0..u1] x [v0..v1] -> [0..1] x [0..1]
*/
public float getRelX(float u) { return (u - u0) / (u1 - u0); }
public float getRelY(float v) { return (v - v0) / (v1 - v0); }
public Coords getClippedCoords(float iw, float ih, float w, float h) /*const*/ {
Coords cr = new Coords(w, h, this);
if (u1 > iw || u0 < 0) {
if (u0 >= iw || u1 <= 0) return null;
if (u1 > iw) {
cr.x1 = w * getRelX(iw);
cr.u1 = iw;
}
if (u0 < 0) {
cr.x0 = w * getRelX(0);
cr.u0 = 0;
}
}
if (v1 > ih || v0 < 0) {
if (v0 >= ih || v1 <= 0) return null;
if (v1 > ih) {
cr.y1 = h * getRelY(ih);
cr.v1 = ih;
}
if (v0 < 0) {
cr.y0 = h * getRelY(0);
cr.v0 = 0;
}
}
return cr;
}
}