RGB8Color
ColorRampLookup(const short h,
const ColorRamp* ramp_colors,
const int numramp,
const unsigned char interp_levels)
{
assert(ramp_colors != NULL);
assert(numramp >= 2);
unsigned short f, of;
unsigned short is = 1<<interp_levels;
// gone past end, so use last color
if (h >= ramp_colors[numramp - 1].h) {
return RGB8Color(ramp_colors[numramp-1].r,
ramp_colors[numramp-1].g,
ramp_colors[numramp-1].b);
}
for (int i = numramp - 2; i >= 0; i--) {
assert(ramp_colors[i].h < ramp_colors[i + 1].h);
if (h >= ramp_colors[i].h) {
if (interp_levels) {
f = (unsigned short)(h - ramp_colors[i].h) * is
/ (unsigned short)(ramp_colors[i + 1].h - ramp_colors[i].h);
of = is - f;
return RGB8Color((f * ramp_colors[i + 1].r + of * ramp_colors[i].r) >> interp_levels,
(f * ramp_colors[i + 1].g + of * ramp_colors[i].g) >> interp_levels,
(f * ramp_colors[i + 1].b + of * ramp_colors[i].b) >> interp_levels);
} else {
return RGB8Color(ramp_colors[i].r, ramp_colors[i].g, ramp_colors[i].b);
}
}
}
bool
ParseHexColor(const TCHAR *buffer, RGB8Color &color)
{
if (*buffer != _T('#'))
return false;
buffer++;
TCHAR *endptr;
unsigned value = ParseUnsigned(buffer, &endptr, 16);
if (endptr != buffer + 6)
return false;
uint8_t r = value >> 16;
uint8_t g = value >> 8;
uint8_t b = value;
color = RGB8Color(r, g, b);
return true;
}
constexpr RGB8Color Invert() const {
return RGB8Color(~r, ~g, ~b);
}
RGB8Color
ColorRamp::ToRGB8Color() const
{
return RGB8Color(r, g, b);
}
