void
FormatHexColor(char *buffer, size_t size, const RGB8Color color)
{
assert(size >= 7);
snprintf(buffer, size, "#%02X%02X%02X",
color.Red(), color.Green(), color.Blue());
}
static constexpr RGB8Color
Interpolate(RGB8Color c1, RGB8Color c2,
unsigned f, unsigned of,
unsigned interp_levels)
{
return RGB8Color((f * c2.Red() + of * c1.Red()) >> interp_levels,
(f * c2.Green() + of * c1.Green()) >> interp_levels,
(f * c2.Blue() + of * c1.Blue()) >> interp_levels);
}
/**
* Shade the given color according to the illumination value.
*
* illum = 64: Contour, mixed with 50% brown
* illum < 0: Shadow, mixed with up to 50% dark blue
* illum > 0: Highlight, mixed with up to 25% yellow
* illum = 0: No shading
*/
gcc_const
inline BGRColor
TerrainShading(const int illum, RGB8Color color)
{
if (illum == -64) {
// brown color mixed in for contours
return BGRColor(MIX(100, color.Red(), 64),
MIX(70, color.Green(), 64),
MIX(26, color.Blue(), 64));
} else if (illum < 0) {
// shadow to blue
int x = std::min(63, -illum);
return BGRColor(MIX(0, color.Red(), x),
MIX(0, color.Green(), x),
MIX(64, color.Blue(), x));
} else if (illum > 0) {
// highlight to yellow
int x = std::min(32, illum / 2);
return BGRColor(MIX(255, color.Red(), x),
MIX(255, color.Green(), x),
MIX(16, color.Blue(), x));
} else
return BGRColor(color.Red(), color.Green(), color.Blue());
}
explicit constexpr Color(RGB8Color other)
:r(Import(other.Red())), g(Import(other.Green())), b(Import(other.Blue())),
a(MAX) {}
explicit constexpr Color(RGB8Color other)
:value({other.Red(), other.Green(), other.Blue(), OPAQUE}) {}
explicit constexpr Color(RGB8Color other)
:value(RGB(other.Red(), other.Green(), other.Blue())) {}
int main(int argc, char **argv)
{
const ColorRamp ramp[] = {
{0, 0xff, 0x80, 0x00},
{1000, 0x00, 0x40, 0xcc},
};
const ColorRamp ramp2[] = {
{-1000, 0x00, 0x00, 0xff},
{ -1, 0x00, 0xff, 0xff},
{ 0, 0xff, 0xff, 0x00},
{ 1000, 0xff, 0x00, 0x00},
};
RGB8Color color;
plan_tests(39);
// Test lower limit
color = ColorRampLookup(0, ramp, 2);
ok1(color.Red() == 0xff);
ok1(color.Green() == 0x80);
ok1(color.Blue() == 0x00);
// Test below lower limit
color = ColorRampLookup(-100, ramp, 2);
ok1(color.Red() == 0xff);
ok1(color.Green() == 0x80);
ok1(color.Blue() == 0x00);
// Test upper limit
color = ColorRampLookup(1000, ramp, 2);
ok1(color.Red() == 0x00);
ok1(color.Green() == 0x40);
ok1(color.Blue() == 0xcc);
// Test above upper limit
color = ColorRampLookup(1500, ramp, 2);
ok1(color.Red() == 0x00);
ok1(color.Green() == 0x40);
ok1(color.Blue() == 0xcc);
// Test middle
color = ColorRampLookup(500, ramp, 2);
ok1(color.Red() == 0x7f);
ok1(color.Green() == 0x60);
ok1(color.Blue() == 0x66);
// Test lower limit
color = ColorRampLookup(-1000, ramp2, 4);
ok1(color.Red() == 0x00);
ok1(color.Green() == 0x00);
ok1(color.Blue() == 0xff);
// Test below lower limit
color = ColorRampLookup(-2000, ramp2, 4);
ok1(color.Red() == 0x00);
ok1(color.Green() == 0x00);
ok1(color.Blue() == 0xff);
// Test upper limit
color = ColorRampLookup(1000, ramp2, 4);
ok1(color.Red() == 0xff);
ok1(color.Green() == 0x00);
ok1(color.Blue() == 0x00);
// Test above upper limit
color = ColorRampLookup(2000, ramp2, 4);
ok1(color.Red() == 0xff);
ok1(color.Green() == 0x00);
ok1(color.Blue() == 0x00);
// Test interpolation point 1
color = ColorRampLookup(0, ramp2, 4);
ok1(color.Red() == 0xff);
ok1(color.Green() == 0xff);
ok1(color.Blue() == 0x00);
// Test interpolation point 2
color = ColorRampLookup(-1, ramp2, 4);
ok1(color.Red() == 0x00);
ok1(color.Green() == 0xff);
ok1(color.Blue() == 0xff);
// Test intermediate point 1
color = ColorRampLookup(500, ramp2, 4);
ok1(color.Red() == 0xff);
ok1(color.Green() == 0x7f);
ok1(color.Blue() == 0x00);
// Test intermediate point 2
color = ColorRampLookup(-500, ramp2, 4);
ok1(color.Red() == 0x00);
ok1(color.Green() == 0x7f);
ok1(color.Blue() == 0xff);
return exit_status();
}
