com.ctreber.acearth.shader.Shader Maven / Gradle / Ivy
Show all versions of plantuml Show documentation
package com.ctreber.acearth.shader;
import java.awt.Color;
import com.ctreber.acearth.projection.Projection;
import com.ctreber.acearth.scanbit.BitGeneratorMap;
import com.ctreber.acearth.util.Coordinate;
import com.ctreber.acearth.util.Point3D;
/**
* A shader computes Colors for a row of pixel types, depending
* on lighting parameters.
*
* © 2002 Christian Treber, [email protected] (Nov 11, 2002)
* @author Christian Treber, [email protected]
*
*/
abstract public class Shader
{
private static final Color COLOR_SPACE = Color.black;
private static final Color COLOR_STAR = Color.white;
private static final Color COLOR_WATER = Color.blue;
private static final Color COLOR_LAND = Color.green;
// Brown
//static final Color COLOR_LAND = new Color(255, 136, 25);
private static final Color COLOR_GRID_LAND = Color.white;
// Bright blue
private static final Color COLOR_GRID_WATER = new Color(128, 128, 255);
/** Needed to calculate lighting vectors. */
Projection fProjection;
// Stuff below only needed when shading.
private Coordinate fSunPos;
private double fNightSideBrightness;
private double fDaySideBrightness;
private double fTerminatorDiscontinuity;
private double fDaySideValueBase;
private double fDaySideValueRange;
Point3D fLightVector;
abstract public Color[] getShadedColors(int pRowNo, int[] pRowTypes);
public void init()
{
// Precompute shading parameters. I personally find the terminator
// stuff is obscure and might as well be left out.
final double tmp = fTerminatorDiscontinuity / 100;
// 100%: day, 0%: night
fDaySideValueBase = (int)(tmp * fDaySideBrightness +
(1 - tmp) * fNightSideBrightness);
fDaySideValueRange = fDaySideBrightness - fDaySideValueBase;
fLightVector = fProjection.rotate(fSunPos.getPoint3D());
}
Color getShadedColorForType(int pType, double pSunValue)
{
double lBrightness;
if(pSunValue < 0)
{
// The sun is below the horizon.
lBrightness = fNightSideBrightness / 100;
} else
{
// The sun is above the horizon. The brightness will range from
// the base to the maximum value.
lBrightness = (fDaySideValueBase + pSunValue * fDaySideValueRange) / 100;
}
if(lBrightness > 1.0)
{
lBrightness = 1.0;
}
switch(pType)
{
case BitGeneratorMap.PixTypeSpace:
return COLOR_SPACE;
case BitGeneratorMap.PixTypeStar:
return COLOR_STAR;
case BitGeneratorMap.PixTypeGridLand:
return shade(COLOR_GRID_LAND, lBrightness);
case BitGeneratorMap.PixTypeGridWater:
return shade(COLOR_GRID_WATER, lBrightness);
case BitGeneratorMap.PixTypeLand:
return shade(COLOR_LAND, lBrightness);
case BitGeneratorMap.PixTypeWater:
return shade(COLOR_WATER, lBrightness);
}
return null;
}
private static Color shade(Color pColor, double pBrightness)
{
return new Color((int)(pColor.getRed() * pBrightness),
(int)(pColor.getGreen() * pBrightness),
(int)(pColor.getBlue() * pBrightness));
}
public void setProjection(Projection pProjection)
{
fProjection = pProjection;
}
public void setSunPos(Coordinate pSunPos)
{
fSunPos = pSunPos;
}
public void setDaySideBrightness(double pDaySideBrightness)
{
fDaySideBrightness = pDaySideBrightness;
}
public void setNightSideBrightness(double pNightSideBrightness)
{
fNightSideBrightness = pNightSideBrightness;
}
public void setTerminatorDiscontinuity(double pTerminatorDiscontinuity)
{
fTerminatorDiscontinuity = pTerminatorDiscontinuity;
}
}