Improved Spare remapping and Brush recolorizing, with new color-matching formula provided by DawnBringer (Perceptual color-distance with 25 brightness weigth-in). Fix in 'Copy to spare/Palette & remap' : Transparent color of the spare wasn't renumbered accordingly.

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1613 416bcca6-2ee7-4201-b75f-2eb2f807beb1

src/brush.c

@@ -806,7 +806,7 @@ void Remap_brush(void)
   //       ne seront pas utilisées par Remap_brush_LOWLEVEL.
   for (color=0;color<=255;color++)
     if (used[color] != 0)
-      used[color]=Best_color(Spare_palette[color].R,Spare_palette[color].G,Spare_palette[color].B);
+      used[color]=Best_color_perceptual(Spare_palette[color].R,Spare_palette[color].G,Spare_palette[color].B);
 
   //   Il reste une couleur non calculée dans la table qu'il faut mettre à
   // jour: c'est la couleur de fond. On l'avait inhibée pour éviter son

src/graph.c

@@ -673,13 +673,16 @@ void Remap_spare(void)
   //       ne seront pas utilisées par Remap_general_lowlevel.
   for (color=0;color<=255;color++)
     if (used[color])
-      used[color]=Best_color(Spare_palette[color].R,Spare_palette[color].G,Spare_palette[color].B);
+      used[color]=Best_color_perceptual(Spare_palette[color].R,Spare_palette[color].G,Spare_palette[color].B);
 
   //   Maintenant qu'on a une super table de conversion qui n'a que le nom
   // qui craint un peu, on peut faire l'échange dans la brosse de toutes les
   // teintes.
   for (layer=0; layer<Spare_backups->Pages->Nb_layers; layer++)
     Remap_general_lowlevel(used,Spare_backups->Pages->Image[layer],Spare_image_width,Spare_image_height,Spare_image_width);
+    
+  // Change transparent color index
+  Spare_backups->Pages->Transparent_color=used[Spare_backups->Pages->Transparent_color];
 }
 
 

src/windows.c

@@ -2584,22 +2584,14 @@ void Display_all_screen(void)
 
 byte Best_color(byte r,byte g,byte b)
 {
-  // This "static" allows the loop to start on the last successful match.
+  int col;
-  // If the same color is requested again (and it happens often) and the match
-  // was perfect, it allows an early exit that avoids
-  // 255 computations of color distance.
-  // This system still works with no bad effects when the palette changes.
-  static byte col=0;
-  
-  byte  end_color;
   int   delta_r,delta_g,delta_b;
   int   dist;
   int   best_dist=0x7FFFFFFF;
   int   rmean;
   byte  best_color=0;
 
-  end_color=col;
+  for (col=0; col<256; col++)
-  do
   {
     if (!Exclude_color[col])
     {
@@ -2619,9 +2611,7 @@ byte Best_color(byte r,byte g,byte b)
         best_color=col;
       }
     }
-    // Loop  
+  }
-    col++;
-  } while(col!=end_color);
 
   return best_color;
 }
@@ -2658,6 +2648,51 @@ byte Best_color_nonexcluded(byte red,byte green,byte blue)
 }
 
 
+
+byte Best_color_perceptual(byte r,byte g,byte b)
+{
+  
+  int col;  
+  float best_diff=255.0*1.56905;
+  byte  best_color=0;
+  float target_bri;
+  float bri;
+  float diff_b, diff_c, diff;
+
+  // Similar to Perceptual_lightness();
+  target_bri = sqrt(0.26*r*0.26*r + 0.55*g*0.55*g + 0.19*b*0.19*b);
+  
+  for (col=0; col<256; col++)
+  {
+    if (Exclude_color[col])
+      continue;
+
+    diff_c = sqrt(
+      (0.26*(Main_palette[col].R-r))*
+      (0.26*(Main_palette[col].R-r))+
+      (0.55*(Main_palette[col].G-g))*
+      (0.55*(Main_palette[col].G-g))+
+      (0.19*(Main_palette[col].B-b))*
+      (0.19*(Main_palette[col].B-b)));
+    // Exact match
+    if (diff_c==0)
+      return col;
+
+    bri = sqrt(0.26*Main_palette[col].R*0.26*Main_palette[col].R + 0.55*Main_palette[col].G*0.55*Main_palette[col].G + 0.19*Main_palette[col].B*0.19*Main_palette[col].B);
+    diff_b = abs(target_bri-bri);
+
+    diff=0.25*(diff_b-diff_c)+diff_c;
+    if (diff<best_diff)
+    {
+      best_diff=diff;
+      best_color=col;
+    } 
+  }
+
+  return best_color;
+}
+
+
 byte Old_black;
 byte Old_dark;
 byte Old_light;

src/windows.h

@@ -99,6 +99,7 @@ void Window_display_icon_sprite(word x_pos,word y_pos,byte type);
 
 byte Best_color(byte red,byte green,byte blue);
 byte Best_color_nonexcluded(byte red,byte green,byte blue);
+byte Best_color_perceptual(byte r,byte g,byte b);
 
 void Horizontal_XOR_line_zoom(short x_pos, short y_pos, short width);
 void Vertical_XOR_line_zoom(short x_pos, short y_pos, short height);