001// License: GPL. For details, see LICENSE file. 002package org.openstreetmap.josm.tools; 003 004import java.awt.Color; 005import java.awt.FontMetrics; 006import java.awt.Graphics2D; 007 008/** 009 * Utility class that helps to work with color scale for coloring GPX tracks etc. 010 * @since 7319 011 */ 012public final class ColorScale { 013 private double min, max; 014 private Color noDataColor; 015 private Color belowMinColor; 016 private Color aboveMaxColor; 017 018 private Color[] colors; 019 private String title = ""; 020 private int intervalCount = 5; 021 022 private ColorScale() { 023 024 } 025 026 public static ColorScale createHSBScale(int count) { 027 ColorScale sc = new ColorScale(); 028 sc.colors = new Color[count]; 029 for (int i = 0; i < count; i++) { 030 sc.colors[i] = Color.getHSBColor(i / 300.0f, 1, 1); 031 } 032 sc.setRange(0, 255); 033 sc.addBounds(); 034 return sc; 035 } 036 037 public static ColorScale createCyclicScale(int count) { 038 ColorScale sc = new ColorScale(); 039 // CHECKSTYLE.OFF: SingleSpaceSeparator 040 // red yellow green blue red 041 int[] h = new int[] {0, 59, 127, 244, 360}; 042 int[] s = new int[] {100, 84, 99, 100}; 043 int[] b = new int[] {90, 93, 74, 83}; 044 // CHECKSTYLE.ON: SingleSpaceSeparator 045 046 sc.colors = new Color[count]; 047 for (int i = 0; i < sc.colors.length; i++) { 048 049 float angle = i / 256f * 4; 050 int quadrant = (int) angle; 051 angle -= quadrant; 052 quadrant = Utils.mod(quadrant+1, 4); 053 054 float vh = h[quadrant] * w(angle) + h[quadrant+1] * (1 - w(angle)); 055 float vs = s[quadrant] * w(angle) + s[Utils.mod(quadrant+1, 4)] * (1 - w(angle)); 056 float vb = b[quadrant] * w(angle) + b[Utils.mod(quadrant+1, 4)] * (1 - w(angle)); 057 058 sc.colors[i] = Color.getHSBColor(vh/360f, vs/100f, vb/100f); 059 } 060 sc.setRange(0, 2*Math.PI); 061 sc.addBounds(); 062 return sc; 063 } 064 065 /** 066 * transition function: 067 * w(0)=1, w(1)=0, 0<=w(x)<=1 068 * @param x number: 0<=x<=1 069 * @return the weighted value 070 */ 071 private static float w(float x) { 072 if (x < 0.5) 073 return 1 - 2*x*x; 074 else 075 return 2*(1-x)*(1-x); 076 } 077 078 public void setRange(double min, double max) { 079 this.min = min; 080 this.max = max; 081 } 082 083 /** 084 * Add standard colors for values below min or above max value 085 */ 086 public void addBounds() { 087 aboveMaxColor = colors[colors.length-1]; 088 belowMinColor = colors[0]; 089 } 090 091 public Color getColor(double value) { 092 if (value < min) return belowMinColor; 093 if (value > max) return aboveMaxColor; 094 if (Double.isNaN(value)) return noDataColor; 095 final int n = colors.length; 096 int idx = (int) ((value-min)*colors.length / (max-min)); 097 if (idx < colors.length) { 098 return colors[idx]; 099 } else { 100 return colors[n-1]; // this happens when value==max 101 } 102 } 103 104 public Color getColor(Number value) { 105 return (value == null) ? noDataColor : getColor(value.doubleValue()); 106 } 107 108 public Color getNoDataColor() { 109 return noDataColor; 110 } 111 112 public void setNoDataColor(Color noDataColor) { 113 this.noDataColor = noDataColor; 114 } 115 116 public ColorScale makeTransparent(int alpha) { 117 for (int i = 0; i < colors.length; i++) { 118 colors[i] = new Color((colors[i].getRGB() & 0xFFFFFF) | ((alpha & 0xFF) << 24), true); 119 } 120 return this; 121 } 122 123 public ColorScale addTitle(String title) { 124 this.title = title; 125 return this; 126 } 127 128 public ColorScale setIntervalCount(int intervalCount) { 129 this.intervalCount = intervalCount; 130 return this; 131 } 132 133 public ColorScale makeReversed() { 134 int n = colors.length; 135 Color tmp; 136 for (int i = 0; i < n/2; i++) { 137 tmp = colors[i]; 138 colors[i] = colors[n-1-i]; 139 colors[n-1-i] = tmp; 140 } 141 tmp = belowMinColor; 142 belowMinColor = aboveMaxColor; 143 aboveMaxColor = tmp; 144 return this; 145 } 146 147 public void drawColorBar(Graphics2D g, int x, int y, int w, int h, double valueScale) { 148 int n = colors.length; 149 150 for (int i = 0; i < n; i++) { 151 g.setColor(colors[i]); 152 if (w < h) { 153 g.fillRect(x, y+i*h/n, w, h/n+1); 154 } else { 155 g.fillRect(x+i*w/n, y, w/n+1, h); 156 } 157 } 158 159 int fw, fh; 160 FontMetrics fm = g.getFontMetrics(); 161 fh = fm.getHeight()/2; 162 fw = fm.stringWidth(String.valueOf(Math.max((int) Math.abs(max*valueScale), 163 (int) Math.abs(min*valueScale)))) + fm.stringWidth("0.123"); 164 g.setColor(noDataColor); 165 if (title != null) { 166 g.drawString(title, x-fw-3, y-fh*3/2); 167 } 168 for (int i = 0; i <= intervalCount; i++) { 169 g.setColor(colors[(int) (1.0*i*n/intervalCount-1e-10)]); 170 final double val = min+i*(max-min)/intervalCount; 171 final String txt = String.format("%.3f", val*valueScale); 172 if (w < h) { 173 g.drawString(txt, x-fw-3, y+i*h/intervalCount+fh/2); 174 } else { 175 g.drawString(txt, x+i*w/intervalCount-fw/2, y+fh-3); 176 } 177 } 178 } 179}