/*
* Copyright (C) 2003, 2004 Jason Bevins (original libnoise code)
* Copyright � 2010 Thomas J. Hodge (java port of libnoise)
*
* This file is part of libnoiseforjava.
*
* libnoiseforjava is a Java port of the C++ library libnoise, which may be found at
* http://libnoise.sourceforge.net/. libnoise was developed by Jason Bevins, who may be
* contacted at jlbezigvins@gmzigail.com (for great email, take off every 'zig').
* Porting to Java was done by Thomas Hodge, who may be contacted at
* libnoisezagforjava@gzagmail.com (remove every 'zag').
*
* libnoiseforjava is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free Software
* Foundation, either version 3 of the License, or (at your option) any later version.
*
* libnoiseforjava 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 for more details.
*
* You should have received a copy of the GNU General Public License along with
* libnoiseforjava. If not, see <http://www.gnu.org/licenses/>.
*
*/
package libnoiseforjava.util;
import libnoiseforjava.exception.ExceptionInvalidParam;
public class RendererNormalMap
{
/// Renders a normal map from a noise map.
///
/// This class renders an image containing the normal vectors from a noise
/// map object. This image can then be used as a bump map for a 3D
/// application or game.
///
/// This class encodes the (x, y, z) components of the normal vector into
/// the (red, green, blue) channels of the image. Like any 24-bit
/// true-color image, the channel values range from 0 to 255. 0
/// represents a normal coordinate of -1.0 and 255 represents a normal
/// coordinate of +1.0.
///
/// You should also specify the <i>bump height</i> before rendering the
/// normal map. The bump height specifies the ratio of spatial resolution
/// to elevation resolution. For example, if your noise map has a spatial
/// resolution of 30 meters and an elevation resolution of one meter, set
/// the bump height to 1.0 / 30.0.
///
/// <b>Rendering the normal map</b>
///
/// To render the image containing the normal map, perform the following
/// steps:
/// - Pass a NoiseMap object to the setSourceNoiseMap() method.
/// - Pass an ImageCafe object to the setDestImage() method.
/// - Call the render() method.
/// The bump height for the normal map.
double bumpHeight;
/// A flag specifying whether wrapping is enabled.
boolean isWrapEnabled;
/// A pointer to the destination image.
ImageCafe destImageCafe;
/// A pointer to the source noise map.
NoiseMap sourceNoiseMap;
public RendererNormalMap () throws ExceptionInvalidParam
{
bumpHeight = 1.0;
isWrapEnabled = false;
destImageCafe = new ImageCafe(0,0);
sourceNoiseMap = new NoiseMap(0,0);
}
public RendererNormalMap (int height, int width) throws ExceptionInvalidParam
{
bumpHeight = 1.0;
isWrapEnabled = false;
destImageCafe = new ImageCafe(height, width);
sourceNoiseMap = new NoiseMap(height, width);
}
/// Calculates the normal vector at a given point on the noise map.
///
/// @param nc The height of the given point in the noise map.
/// @param nr The height of the left neighbor.
/// @param nu The height of the up neighbor.
/// @param bumpHeight The bump height.
///
/// @returns The normal vector represented as a color.
///
/// This method encodes the (x, y, z) components of the normal vector
/// into the (red, green, blue) channels of the returned color. In
/// order to represent the vector as a color, each coordinate of the
/// normal is mapped from the -1.0 to 1.0 range to the 0 to 255 range.
///
/// The bump height specifies the ratio of spatial resolution to
/// elevation resolution. For example, if your noise map has a
/// spatial resolution of 30 meters and an elevation resolution of one
/// meter, set the bump height to 1.0 / 30.0.
///
/// The spatial resolution and elevation resolution are determined by
/// the application.
public ColorCafe calcNormalColor (double nc, double nr, double nu,
double bumpHeight)
{
// Calculate the surface normal.
nc *= bumpHeight;
nr *= bumpHeight;
nu *= bumpHeight;
double ncr = (nc - nr);
double ncu = (nc - nu);
double d = Math.sqrt ((ncu * ncu) + (ncr * ncr) + 1);
double vxc = (nc - nr) / d;
double vyc = (nc - nu) / d;
double vzc = 1.0 / d;
// Map the normal range from the (-1.0 .. +1.0) range to the (0 .. 255)
// range.
int xc, yc, zc;
xc = (int) (Math.floor((vxc + 1.0) * 127.5)) & 0xff;
yc = (int) (Math.floor((vyc + 1.0) * 127.5)) & 0xff;
zc = (int) (Math.floor((vzc + 1.0) * 127.5)) & 0xff;
// left as example of what was here in case above conversion doesn't work.
//zc = (noise::uint8)((noise::uint)((floor)((vzc + 1.0) * 127.5)) & 0xff);
return new ColorCafe (xc, yc, zc, 255);
}
/// Renders the noise map to the destination image.
///
/// @pre setSourceNoiseMap() has been previously called.
/// @pre setDestImage() has been previously called.
///
/// @post The original contents of the destination image is destroyed.
///
/// @throw ExceptionInvalidParam See the preconditions.
public void render () throws ExceptionInvalidParam
{
if ( sourceNoiseMap == null
|| destImageCafe == null
|| sourceNoiseMap.getWidth () <= 0
|| sourceNoiseMap.getHeight () <= 0)
throw new ExceptionInvalidParam ("Invalid Parameter in RendererNormalMap");
int width = sourceNoiseMap.getWidth ();
int height = sourceNoiseMap.getHeight ();
for (int y = 0; y < height; y++)
{
for (int x = 0; x < width; x++)
{
// Calculate the positions of the current point's right and up
// neighbors.
int xRightOffset, yUpOffset;
if (isWrapEnabled)
{
if (x == (int)width - 1)
xRightOffset = -((int)width - 1);
else
xRightOffset = 1;
if (y == (int)height - 1)
yUpOffset = -((int)height - 1);
else
yUpOffset = 1;
}
else
{
if (x == (int)width - 1)
xRightOffset = 0;
else
xRightOffset = 1;
if (y == (int)height - 1)
yUpOffset = 0;
else
yUpOffset = 1;
}
// Get the noise value of the current point in the source noise map
// and the noise values of its right and up neighbors.
double nc = (double)(sourceNoiseMap.getValue(x, y));
double nr = (double)(sourceNoiseMap.getValue((x + xRightOffset),y));
double nu = (double)(sourceNoiseMap.getValue(x, (y + yUpOffset)));
// Calculate the normal product.
destImageCafe.setValue(x,y, (calcNormalColor (nc, nr, nu, bumpHeight)));
// Go to the next point.
//++pSource;
//++pDest;
}
}
}
/// Enables or disables noise-map wrapping.
///
/// @param enable A flag that enables or disables noise-map wrapping.
///
/// This object requires three points (the initial point and the right
/// and up neighbors) to calculate the normal vector at that point.
/// If wrapping is/ enabled, and the initial point is on the edge of
/// the noise map, the appropriate neighbors that lie outside of the
/// noise map will "wrap" to the opposite side(s) of the noise map.
/// Otherwise, the appropriate neighbors are cropped to the edge of
/// the noise map.
///
/// Enabling wrapping is useful when creating spherical and tileable
/// normal maps.
public void enableWrap (boolean enable)
{
isWrapEnabled = enable;
}
/// Returns the bump height.
///
/// @returns The bump height.
///
/// The bump height specifies the ratio of spatial resolution to
/// elevation resolution. For example, if your noise map has a
/// spatial resolution of 30 meters and an elevation resolution of one
/// meter, set the bump height to 1.0 / 30.0.
///
/// The spatial resolution and elevation resolution are determined by
/// the application.
public double getBumpHeight ()
{
return bumpHeight;
}
/// Determines if noise-map wrapping is enabled.
///
/// @returns
/// - @a true if noise-map wrapping is enabled.
/// - @a false if noise-map wrapping is disabled.
///
/// This object requires three points (the initial point and the right
/// and up neighbors) to calculate the normal vector at that point.
/// If wrapping is/ enabled, and the initial point is on the edge of
/// the noise map, the appropriate neighbors that lie outside of the
/// noise map will "wrap" to the opposite side(s) of the noise map.
/// Otherwise, the appropriate neighbors are cropped to the edge of
/// the noise map.
///
/// Enabling wrapping is useful when creating spherical and tileable
/// normal maps.
public boolean isWrapEnabled ()
{
return isWrapEnabled;
}
/// Sets the bump height.
///
/// @param bumpHeight The bump height.
///
/// The bump height specifies the ratio of spatial resolution to
/// elevation resolution. For example, if your noise map has a
/// spatial resolution of 30 meters and an elevation resolution of one
/// meter, set the bump height to 1.0 / 30.0.
///
/// The spatial resolution and elevation resolution are determined by
/// the application.
public void setBumpHeight (double bumpHeight)
{
this.bumpHeight = bumpHeight;
}
/// Sets the destination image.
///
/// @param destImage The destination image.
///
/// The destination image will contain the normal map after a
/// successful call to the render() method.
///
/// The destination image must exist throughout the lifetime of this
/// object unless another image replaces that image.
public void setDestImage (ImageCafe destImage)
{
this.destImageCafe = destImage;
}
/// Sets the source noise map.
///
/// @param sourceNoiseMap The source noise map.
///
/// The destination image must exist throughout the lifetime of this
/// object unless another image replaces that image.
public void setSourceNoiseMap (NoiseMap sourceNoiseMap)
{
this.sourceNoiseMap = sourceNoiseMap;
}
public ImageCafe getDestImageCafe()
{
return destImageCafe;
}
public NoiseMap getSourceNoiseMap()
{
return sourceNoiseMap;
}
public void setDestImageCafe(ImageCafe destImageCafe)
{
this.destImageCafe = destImageCafe;
}
}