|
|
@ -497,6 +497,21 @@ nfbcellidx(const ncplane* n, int row, int col){
|
|
|
|
return fbcellidx(logical_to_virtual(n, row), n->lenx, col);
|
|
|
|
return fbcellidx(logical_to_virtual(n, row), n->lenx, col);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
// is the rgb value greyish (excluding white and black)?
|
|
|
|
|
|
|
|
static inline bool
|
|
|
|
|
|
|
|
rgb_greyish_p(unsigned r, unsigned g, unsigned b){
|
|
|
|
|
|
|
|
const unsigned GREYMASK = 0xf8;
|
|
|
|
|
|
|
|
if((r & GREYMASK) == (g & GREYMASK) && (g & GREYMASK) == (b & GREYMASK)){
|
|
|
|
|
|
|
|
if(r < 16){
|
|
|
|
|
|
|
|
return false; // black
|
|
|
|
|
|
|
|
}else if(r > 240){
|
|
|
|
|
|
|
|
return false; // white
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
// For our first attempt, O(1) uniform conversion from 8-bit r/g/b down to
|
|
|
|
// For our first attempt, O(1) uniform conversion from 8-bit r/g/b down to
|
|
|
|
// ~2.4-bit 6x6x6 cube + greyscale (assumed on entry; I know no way to
|
|
|
|
// ~2.4-bit 6x6x6 cube + greyscale (assumed on entry; I know no way to
|
|
|
|
// even semi-portably recover the palette) proceeds via: map each 8-bit to
|
|
|
|
// even semi-portably recover the palette) proceeds via: map each 8-bit to
|
|
|
@ -504,10 +519,9 @@ nfbcellidx(const ncplane* n, int row, int col){
|
|
|
|
// otherwise, c / 42.7 to map to 6 values.
|
|
|
|
// otherwise, c / 42.7 to map to 6 values.
|
|
|
|
static inline int
|
|
|
|
static inline int
|
|
|
|
rgb_quantize_256(unsigned r, unsigned g, unsigned b){
|
|
|
|
rgb_quantize_256(unsigned r, unsigned g, unsigned b){
|
|
|
|
const unsigned GREYMASK = 0xf8;
|
|
|
|
|
|
|
|
// if all 5 MSBs match, return grey from 24-member grey ramp or pure
|
|
|
|
// if all 5 MSBs match, return grey from 24-member grey ramp or pure
|
|
|
|
// black/white from original 16 (0 and 15, respectively)
|
|
|
|
// black/white from original 16 (0 and 15, respectively)
|
|
|
|
if((r & GREYMASK) == (g & GREYMASK) && (g & GREYMASK) == (b & GREYMASK)){
|
|
|
|
if(rgb_greyish_p(r, g, b)){
|
|
|
|
// 256 / 26 == 9.846
|
|
|
|
// 256 / 26 == 9.846
|
|
|
|
int gidx = r * 5 / 49 - 1;
|
|
|
|
int gidx = r * 5 / 49 - 1;
|
|
|
|
if(gidx < 0){
|
|
|
|
if(gidx < 0){
|
|
|
@ -536,6 +550,9 @@ rgb_quantize_8(unsigned r, unsigned g, unsigned b){
|
|
|
|
static const int MAGENTA = 5;
|
|
|
|
static const int MAGENTA = 5;
|
|
|
|
static const int CYAN = 6;
|
|
|
|
static const int CYAN = 6;
|
|
|
|
static const int WHITE = 7;
|
|
|
|
static const int WHITE = 7;
|
|
|
|
|
|
|
|
if(rgb_greyish_p(r, g, b)){
|
|
|
|
|
|
|
|
return WHITE;
|
|
|
|
|
|
|
|
}
|
|
|
|
if(r < 128){ // we have no red
|
|
|
|
if(r < 128){ // we have no red
|
|
|
|
if(g < 128){ // we have no green
|
|
|
|
if(g < 128){ // we have no green
|
|
|
|
if(b < 128){
|
|
|
|
if(b < 128){
|
|
|
|