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authorLeo Tenenbaum <pommicket@gmail.com>2021-03-03 19:17:48 -0500
committerLeo Tenenbaum <pommicket@gmail.com>2021-03-03 19:17:48 -0500
commite3eb333ae2b07467e14dd9e2f845889f75f01a16 (patch)
tree64599a9b11f757a5e480c9f94b3ddedb57678d4e /math.c
parent74cae07c859e68876ee98b99e1c1761d4c205484 (diff)
start autocomplete
Diffstat (limited to 'math.c')
-rw-r--r--math.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/math.c b/math.c
index 7d16a52..75ec497 100644
--- a/math.c
+++ b/math.c
@@ -639,6 +639,13 @@ static v4 rgba_u32_to_v4(u32 rgba) {
return V4(c[0], c[1], c[2], c[3]);
}
+static u32 rgba_v4_to_u32(v4 color) {
+ return (u32)(color.x * 255) << 24
+ | (u32)(color.y * 255) << 16
+ | (u32)(color.z * 255) << 8
+ | (u32)(color.w * 255);
+}
+
// returns average of red green and blue components of color
static float rgba_brightness(u32 color) {
u8 r = (u8)(color >> 24), g = (u8)(color >> 16), b = (u8)(color >> 8);
@@ -740,3 +747,79 @@ static Rect rect_shrink(Rect r, float amount) {
r.size.y = maxf(r.size.y, 0);
return r;
}
+
+static v4 color_rgba_to_hsva(v4 rgba) {
+ float R = rgba.x, G = rgba.y, B = rgba.z, A = rgba.w;
+ float M = maxf(R, maxf(G, B));
+ float m = minf(R, minf(G, B));
+ float C = M - m;
+ float H = 0;
+ if (C == 0)
+ H = 0;
+ if (M == R)
+ H = fmodf((G - B) / C, 6);
+ else if (M == G)
+ H = (B - R) / C + 2;
+ else if (M == B)
+ H = (R - G) / C + 4;
+ H *= 60;
+ float V = M;
+ float S = V == 0 ? 0 : C / V;
+ return V4(H, S, V, A);
+}
+
+static v4 color_hsva_to_rgba(v4 hsva) {
+ float H = hsva.x, S = hsva.y, V = hsva.z, A = hsva.w;
+ H /= 60;
+ float C = S * V;
+ float X = C * (1 - fabsf(fmodf(H, 2) - 1));
+ float R, G, B;
+ if (H <= 1)
+ R=C, G=X, B=0;
+ else if (H <= 2)
+ R=X, G=C, B=0;
+ else if (H <= 3)
+ R=0, G=C, B=X;
+ else if (H <= 4)
+ R=0, G=X, B=C;
+ else if (H <= 5)
+ R=X, G=0, B=C;
+ else
+ R=C, G=0, B=X;
+
+ float m = V-C;
+ R += m;
+ G += m;
+ B += m;
+ return V4(R, G, B, A);
+}
+
+static u32 color_interpolate(float x, u32 color1, u32 color2) {
+ x = x * x * (3 - 2*x); // hermite interpolation
+
+ v4 c1 = rgba_u32_to_v4(color1), c2 = rgba_u32_to_v4(color2);
+ // to make it interpolate more nicely, convert to hsv, interpolate in that space, then convert back
+ c1 = color_rgba_to_hsva(c1);
+ c2 = color_rgba_to_hsva(c2);
+ float h1 = c1.x, s1 = c1.y, v1 = c1.z, a1 = c1.w;
+ float h2 = c2.x, s2 = c2.y, v2 = c2.z, a2 = c2.w;
+
+ float s_out = lerpf(x, s1, s2);
+ float v_out = lerpf(x, v1, v2);
+ float a_out = lerpf(x, a1, a2);
+
+ float h_out;
+ // because hue is on a circle, we need to make sure we take the shorter route around the circle
+ if (fabsf(h1 - h2) < 180) {
+ h_out = lerpf(x, h1, h2);
+ } else if (h1 > h2) {
+ h_out = lerpf(x, h1, h2 + 360);
+ } else {
+ h_out = lerpf(x, h1 + 360, h2);
+ }
+ h_out = fmodf(h_out, 360);
+
+ v4 c_out = V4(h_out, s_out, v_out, a_out);
+ c_out = color_hsva_to_rgba(c_out);
+ return rgba_v4_to_u32(c_out);
+}