Lua: matchcolor2() now takes an optional argument that is the weight of lightness in color proximity algorithm (instead of the 0.25 default).

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1821 416bcca6-2ee7-4201-b75f-2eb2f807beb1
This commit is contained in:
Yves Rizoud 2011-07-18 23:08:33 +00:00
parent f2316f12e2
commit 8ba389e06b
3 changed files with 58 additions and 3 deletions

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@ -711,12 +711,23 @@ int L_MatchColor2(lua_State* L)
int c;
int nb_args=lua_gettop(L);
LUA_ARG_LIMIT (3, "matchcolor2");
if (nb_args < 3 || nb_args > 4)
{
return luaL_error(L, "matchcolor2: Expected 3 or 4 arguments, but found %d.", nb_args);
}
LUA_ARG_NUMBER(1, "matchcolor2", r, -DBL_MAX, DBL_MAX);
LUA_ARG_NUMBER(2, "matchcolor2", g, -DBL_MAX, DBL_MAX);
LUA_ARG_NUMBER(3, "matchcolor2", b, -DBL_MAX, DBL_MAX);
c = Best_color_perceptual(clamp_byte(r),clamp_byte(g),clamp_byte(b));
if (nb_args == 3)
{
c = Best_color_perceptual(clamp_byte(r),clamp_byte(g),clamp_byte(b));
}
else // nb_args == 4
{
float weight;
LUA_ARG_NUMBER(4, "matchcolor2", weight, -DBL_MAX, DBL_MAX);
c = Best_color_perceptual_weighted(clamp_byte(r),clamp_byte(g),clamp_byte(b),weight);
}
lua_pushinteger(L, c);
return 1;
}

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@ -2720,6 +2720,49 @@ byte Best_color_perceptual(byte r,byte g,byte b)
return best_color;
}
byte Best_color_perceptual_weighted(byte r,byte g,byte b,float l_weight)
{
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=l_weight*(diff_b-diff_c)+diff_c;
if (diff<best_diff)
{
best_diff=diff;
best_color=col;
}
}
return best_color;
}
byte Best_color_perceptual_except(byte r,byte g,byte b, byte except)
{

View File

@ -101,6 +101,7 @@ 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);
byte Best_color_perceptual_except(byte r,byte g,byte b, byte except);
byte Best_color_perceptual_weighted(byte r,byte g,byte b, float weight);
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);