Changeset 5010 in orxonox.OLD for orxonox/trunk/src/lib/util

Timestamp:

Aug 14, 2005, 3:48:22 AM (19 years ago)

Author:

bensch

Message:

orxonox/trunk: better color-transformation-algorithms

Location:

orxonox/trunk/src/lib/util

Files:

• color.cc (moved) (moved from orxonox/trunk/src/util/color.cc) (1 diff)
• color.h (moved) (moved from orxonox/trunk/src/util/color.h) (1 diff)

orxonox/trunk/src/lib/util/color.cc

@@ -20 +20 @@
 
 #include "color.h"
+#include "vector.h"
 
 using namespace std;
 
-Vector Color::RGBtoHSV (Vector RGB)
+
+
+
+#include <stdio.h>
+
+// Needed by rgb2hsv()
+float Color::maxrgb(float r, float g, float b)
 {
-  Vector HSV;
+  float max;
 
-  float var_Min = min( RGB.x, RGB.y, RGB.z );    //Min. value of RGB
-  float var_Max = max( RGB.x, RGB.y, RGB.z );    //Max. value of RGB
-  float del_Max = var_Max - var_Min;             //Delta RGB value
-
-  flaot V = var_Max;
-
-  if ( del_Max == 0 )                     //This is a gray, no chroma...
-  {
-    HSV.x = 0                                //HSV results = 0 ÷ 1
-    HSV.y = 0
-  }
-  else                                    //Chromatic data...
-  {
-    HSV.y = del_Max / var_Max;
-
-    float del_R = ( ( ( var_Max - RGB.x ) / 6 ) + ( del_Max / 2 ) ) / del_Max;
-    float del_G = ( ( ( var_Max - RGB.y ) / 6 ) + ( del_Max / 2 ) ) / del_Max;
-    float del_B = ( ( ( var_Max - RGB.z ) / 6 ) + ( del_Max / 2 ) ) / del_Max;
-
-    if ( RGB.x == var_Max )
-      HSV.x = del_B - del_G;
-    else if ( var_G == var_Max )
-      HSV.x = ( 1 / 3 ) + del_R - del_B;
-    else if ( var_B == var_Max )
-      HSV.z = ( 2 / 3 ) + del_G - del_R;
-
-    if ( HSV.x < 0 ) ; HSV.x += 1;
-    if ( HSV.x > 1 ) ; HSV.x -= 1;
-  }
-  return HSV;
+  if( r > g)
+    max = r;
+  else
+    max = g;
+  if( b > max )
+    max = b;
+  return( max );
 }
 
 
-Vector Color::HSVtoRGB (Vector HSV)
+// Needed by rgb2hsv()
+float Color::minrgb(float r,float g,float b)
 {
+  float min;
 
+  if( r < g)
+    min = r;
+  else
+    min = g;
+  if( b < min )
+    min = b;
+  return( min );
 }
+
+
+/* Taken from "Fund'l of 3D Computer Graphics", Alan Watt (1989)
+   Assumes (r,g,b) range from 0.0 to 1.0
+   Sets h in degrees: 0.0 to 360.;
+      s,v in [0.,1.]
+*/
+Vector Color::RGBtoHSV(const Vector& RGB)
+{
+  float r = RGB.x;
+  float g = RGB.y;
+  float b = RGB.z;
+
+  float h=0,s=1.0,v=1.0;
+  float max_v,min_v,diff,r_dist,g_dist,b_dist;
+  float undefined = 0.0;
+
+  max_v = maxrgb(r,g,b);
+  min_v = minrgb(r,g,b);
+  diff = max_v - min_v;
+  v = max_v;
+
+  if( max_v != 0 )
+    s = diff/max_v;
+  else
+    s = 0.0;
+  if( s == 0 )
+    h = undefined;
+  else {
+    r_dist = (max_v - r)/diff;
+    g_dist = (max_v - g)/diff;
+    b_dist = (max_v - b)/diff;
+    if( r == max_v )
+      h = b_dist - g_dist;
+    else
+      if( g == max_v )
+        h = 2 + r_dist - b_dist;
+    else
+      if( b == max_v )
+        h = 4 + g_dist - r_dist;
+    else
+      printf("rgb2hsv::How did I get here?\n");
+    h *= 60;
+    if( h < 0)
+      h += 360.0;
+  }
+  return Vector(h, s, v);
+}
+
+/* Taken from "Fund'l of 3D Computer Graphics", Alan Watt (1989)
+   Assumes H in degrees, s,v in [0.,1.0];
+   (r,g,b) range from 0.0 to 1.0
+*/
+Vector Color::HSVtoRGB(const Vector& HSV)
+{
+  float h = HSV.x;
+  float s = HSV.y;
+  float v = HSV.z;
+  float r=0, g=0, b=0;
+  float f,p,q,t;
+  int i;
+
+  if( s == 0 ) {
+    r = v;
+    g = v;
+    b = v;
+  }
+  else {
+    if(h == 360.)
+      h = 0.0;
+    h /= 60.;
+    i = (int) h;
+    f = h - i;
+    p = v*(1-s);
+    q = v*(1-(s*f));
+    t = v*(1-s*(1-f));
+    switch(i) {
+      case 0:
+        r = v;
+        g = t;
+        b = p;
+        break;
+      case 1:
+        r = q;
+        g = v;
+        b = p;
+        break;
+      case 2:
+        r = p;
+        g = v;
+        b = t;
+        break;
+      case 3:
+        r = p;
+        g = q;
+        b = v;
+        break;
+      case 4:
+        r = t;
+        g = p;
+        b = v;
+        break;
+      case 5:
+        r = v;
+        g = p;
+        b = q;
+        break;
+      default:
+        r = 1.0;
+        g = 1.0;
+        b = 1.0;
+      //printf("hsv2rgb::How did I get here?\n");
+      // printf("h: %f, s: %f, v: %f; i:  %d\n",hin,s,v,i);
+        break;
+    }
+  }
+  return Vector(r,g,b);
+}

orxonox/trunk/src/lib/util/color.h

@@ -15 +15 @@
 class Color
 {
-  Vector RGBtoHSV (Vector RGB);
-  Vector HSVtoRGB (Vector HSV);
+  public:
+  static Vector RGBtoHSV (const Vector& RGB);
+  static Vector HSVtoRGB (const Vector& HSV);
+
+  static float minrgb(float r, float g, float b);
+  static float maxrgb(float r, float g, float b);
 };