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Math lib: optimize hsv/rgb conversion

This commit is contained in:
Campbell Barton 2013-12-08 17:20:53 +11:00
parent 0f22eb8564
commit 8a9a060b67
1 changed files with 79 additions and 67 deletions
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146
source/blender/blenlib/intern/math_color.c
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@ -39,53 +39,58 @@
void hsv_to_rgb(float h, float s, float v, float *r, float *g, float *b)
{
if (UNLIKELY(s == 0.0f)) {
*r = v;
*g = v;
*b = v;
}
else {
float i, f, p, q, t;
if (s != 0.0f) {
float i, f, p;
h = (h - floorf(h)) * 6.0f;
i = floorf(h);
f = h - i;
p = v * (1.0f - s);
q = v * (1.0f - (s * f));
t = v * (1.0f - (s * (1.0f - f)));
switch ((int)i) {
case 0:
*r = v;
*g = t;
*b = p;
break;
case 1:
*r = q;
*g = v;
*b = p;
break;
case 2:
*r = p;
*g = v;
*b = t;
break;
case 3:
*r = p;
*g = q;
*b = v;
break;
case 4:
*r = t;
*g = p;
*b = v;
break;
case 5:
*r = v;
*g = p;
*b = q;
break;
/* avoid computing q/t when not needed */
p = (v * (1.0f - s));
#define q (v * (1.0f - (s * f)))
#define t (v * (1.0f - (s * (1.0f - f))))
/* faster to compare floats then int conversion */
if (i < 1.0f) {
*r = v;
*g = t;
*b = p;
}
else if (i < 2.0f) {
*r = q;
*g = v;
*b = p;
}
else if (i < 3.0f) {
*r = p;
*g = v;
*b = t;
}
else if (i < 4.0f) {
*r = p;
*g = q;
*b = v;
}
else if (i < 5.0f) {
*r = t;
*g = p;
*b = v;
}
else {
*r = v;
*g = p;
*b = q;
}
#undef q
#undef t
}
else {
*r = v;
*g = v;
*b = v;
}
}
@ -223,8 +228,7 @@ void hex_to_rgb(char *hexcol, float *r, float *g, float *b)
void rgb_to_hsv(float r, float g, float b, float *lh, float *ls, float *lv)
{
float h, s, v;
float cmax, cmin, cdelta;
float rc, gc, bc;
float cmax, cmin;
cmax = r;
cmin = r;
@ -234,37 +238,45 @@ void rgb_to_hsv(float r, float g, float b, float *lh, float *ls, float *lv)
cmin = (b < cmin ? b : cmin);
v = cmax; /* value */
if (cmax != 0.0f)
s = (cmax - cmin) / cmax;
else {
s = 0.0f;
}
if (s == 0.0f)
h = -1.0f;
else {
cdelta = cmax - cmin;
rc = (cmax - r) / cdelta;
gc = (cmax - g) / cdelta;
bc = (cmax - b) / cdelta;
if (cmax != 0.0f) {
float cdelta;
if (r == cmax) {
h = bc - gc;
}
else if (g == cmax) {
h = 2.0f + rc - bc;
cdelta = cmax - cmin;
s = cdelta / cmax;
if (s != 0.0f) {
float rc, gc, bc;
rc = (cmax - r) / cdelta;
gc = (cmax - g) / cdelta;
bc = (cmax - b) / cdelta;
if (r == cmax) {
h = bc - gc;
if (h < 0.0f) {
h += 6.0f;
}
}
else if (g == cmax) {
h = 2.0f + rc - bc;
}
else {
h = 4.0f + gc - rc;
}
h *= (1.0f / 6.0f);
}
else {
h = 4.0f + gc - rc;
h = 0.0f;
}
h = h * 60.0f;
if (h < 0.0f)
h += 360.0f;
}
else {
h = 0.0f;
s = 0.0f;
}
*lh = h;
*ls = s;
*lh = h / 360.0f;
if (*lh < 0.0f) *lh = 0.0f;
*lv = v;
}