Add color manipulation utilities

1 files changed, 618 insertions, 0 deletions

diff --git a/src/Color.c b/src/Color.c
new file mode 100644
index 0000000..d264d1e
--- /dev/null
+++ b/src/Color.c
@@ -0,0 +1,618 @@
+#include "BH/Common.h"
+#include <BH/Color.h>
+#include <math.h>
+
+
+#define MIN(a,b)        (((a)<(b))?(a):(b))
+#define MAX(a,b)        (((a)>(b))?(a):(b))
+
+
+/* Conversion between RGB <-> HSL/HSV has error of around ~ 0.009% */
+#define DEGREE_MULT     1.8204444e02f
+
+
+void BH_ColorRGBA8(const BH_Color *color,
+                   uint8_t *r,
+                   uint8_t *g,
+                   uint8_t *b,
+                   uint8_t *a)
+{
+    BH_Color tmp;
+
+    BH_ColorToRGBA(color, &tmp);
+    *r = tmp.data.rgba.r >> 8;
+    *g = tmp.data.rgba.g >> 8;
+    *b = tmp.data.rgba.b >> 8;
+    *a = tmp.data.rgba.a >> 8;
+}
+
+void BH_ColorRGBA16(const BH_Color *color,
+                    uint16_t *r,
+                    uint16_t *g,
+                    uint16_t *b,
+                    uint16_t *a)
+{
+    BH_Color tmp;
+
+    BH_ColorToRGBA(color, &tmp);
+    *r = tmp.data.rgba.r;
+    *g = tmp.data.rgba.g;
+    *b = tmp.data.rgba.b;
+    *a = tmp.data.rgba.a;
+}
+
+
+void BH_ColorRGBAf(const BH_Color *color,
+                   float *r,
+                   float *g,
+                   float *b,
+                   float *a)
+{
+    BH_Color tmp;
+
+    BH_ColorToRGBA(color, &tmp);
+    *r = tmp.data.rgba.r / 65535.0f;
+    *g = tmp.data.rgba.g / 65535.0f;
+    *b = tmp.data.rgba.b / 65535.0f;
+    *a = tmp.data.rgba.a / 65535.0f;
+}
+
+
+void BH_ColorSetRGBA8(BH_Color *color,
+                      uint8_t r,
+                      uint8_t g,
+                      uint8_t b,
+                      uint8_t a)
+{
+    color->type = BH_COLOR_TYPE_RGBA;
+    color->data.rgba.r = (uint16_t)r * 0x0101;
+    color->data.rgba.g = (uint16_t)g * 0x0101;
+    color->data.rgba.b = (uint16_t)b * 0x0101;
+    color->data.rgba.a = (uint16_t)a * 0x0101;
+}
+
+
+void BH_ColorSetRGBA16(BH_Color *color,
+                       uint16_t r,
+                       uint16_t g,
+                       uint16_t b,
+                       uint16_t a)
+{
+    color->type = BH_COLOR_TYPE_RGBA;
+    color->data.rgba.r = r;
+    color->data.rgba.g = g;
+    color->data.rgba.b = b;
+    color->data.rgba.a = a;
+}
+
+
+void BH_ColorSetRGBAf(BH_Color *color,
+                      float r,
+                      float g,
+                      float b,
+                      float a)
+{
+    r = MAX(MIN(1.0f, r), 0.0f);
+    g = MAX(MIN(1.0f, g), 0.0f);
+    b = MAX(MIN(1.0f, b), 0.0f);
+    a = MAX(MIN(1.0f, a), 0.0f);
+
+    color->type = BH_COLOR_TYPE_RGBA;
+    color->data.rgba.r = r * 65535.0f;
+    color->data.rgba.g = g * 65535.0f;
+    color->data.rgba.b = b * 65535.0f;
+    color->data.rgba.a = a * 65535.0f;
+}
+
+
+void BH_ColorHSVAf(const BH_Color *color,
+                   float *h,
+                   float *s,
+                   float *v,
+                   float *a)
+{
+    BH_Color tmp;
+
+    BH_ColorToHSVA(color, &tmp);
+    *h = tmp.data.hsva.h / DEGREE_MULT;
+    *s = tmp.data.hsva.s / 65535.0f;
+    *v = tmp.data.hsva.v / 65535.0f;
+    *a = tmp.data.hsva.a / 65535.0f;
+}
+
+
+void BH_ColorSetHSVAf(BH_Color *color,
+                      float h,
+                      float s,
+                      float v,
+                      float a)
+{
+    while (h >= 360.0f)
+        h -= 360.0f;
+    while (h < 0.0f)
+        h += 360.0f;
+
+    s = MAX(MIN(1.0f, s), 0.0f);
+    v = MAX(MIN(1.0f, v), 0.0f);
+
+    color->type = BH_COLOR_TYPE_HSVA;
+    color->data.hsva.h = h * DEGREE_MULT;
+    color->data.hsva.s = s * 65535.0f;
+    color->data.hsva.v = v * 65535.0f;
+    color->data.hsva.a = a * 65535.0f;
+}
+
+
+void BH_ColorHSLAf(const BH_Color *color,
+                   float *h,
+                   float *s,
+                   float *l,
+                   float *a)
+{
+    BH_Color tmp;
+
+    BH_ColorToHSLA(color, &tmp);
+    *h = tmp.data.hsla.h / DEGREE_MULT;
+    *s = tmp.data.hsla.s / 65535.0f;
+    *l = tmp.data.hsla.l / 65535.0f;
+    *a = tmp.data.hsla.a / 65535.0f;
+}
+
+
+void BH_ColorSetHSLAf(BH_Color *color,
+                      float h,
+                      float s,
+                      float l,
+                      float a)
+{
+    while (h >= 360.0f)
+        h -= 360.0f;
+    while (h < 0.0f)
+        h += 360.0f;
+
+    s = MAX(MIN(1.0f, s), 0.0f);
+    l = MAX(MIN(1.0f, l), 0.0f);
+
+    color->type = BH_COLOR_TYPE_HSLA;
+    color->data.hsla.h = h * DEGREE_MULT;
+    color->data.hsla.s = s * 65535;
+    color->data.hsla.l = l * 65535;
+    color->data.hsla.a = a * 65535;
+}
+
+
+/*
+ * Transformations between color models are based on:
+ * Computer Graphics and Geometric Modeling by Max K. Agoston
+ */
+static void rgbToHsv(const BH_Color *color,
+                     BH_Color *out)
+{
+    float min, max, d, r, g, b, a, h, s, v;
+
+    BH_ColorRGBAf(color, &r, &g, &b, &a);
+    max = MAX(MAX(r, g), b);
+    min = MIN(MIN(r, g), b);
+
+    v = max;
+    s = 0.0f;
+    h = 0.0f;
+    d = max - min;
+
+    if (max)
+        s = d / max;
+
+    if (s)
+    {
+        if (r == max)
+            h = (g - b) / d;
+        else if (g == max)
+            h = 2 + (b - r) / d;
+        else
+            h = 4 + (r - g) / d;
+    }
+
+    BH_ColorSetHSVAf(out, h * 60.0f, s, v, a);
+}
+
+
+static void hsvToRgb(const BH_Color *color,
+                     BH_Color *out)
+{
+    float h, s, v, a, r, g, b, fract, p, q, t;
+    int sextant;
+    BH_ColorHSVAf(color, &h, &s, &v, &a);
+
+    r = v;
+    g = v;
+    b = v;
+
+    if (s)
+    {
+        h /= 60.0f;
+        sextant = (int)h;
+        fract = h - sextant;
+
+        p = v * (1 - s);
+        q = v * (1 - (s * fract));
+        t = v * (1 - (s * (1 - fract)));
+
+        switch (sextant)
+        {
+        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;
+        }
+    }
+
+    BH_ColorSetRGBAf(out, r, g, b, a);
+}
+
+
+static void rgbToHsl(const BH_Color *color,
+                     BH_Color *out)
+{
+    float min, max, d, r, g, b, a, h, s, l;
+
+    BH_ColorRGBAf(color, &r, &g, &b, &a);
+    max = MAX(MAX(r, g), b);
+    min = MIN(MIN(r, g), b);
+
+    l = (max + min) / 2.0;
+    s = 0.0f;
+    h = 0.0f;
+    d =  max - min;
+
+    if (max != min)
+    {
+        if (l <= 0.5f)
+            s = d / (max + min);
+        else
+            s = d / (2.0f - max - min);
+
+        if (r == max)
+            h = (g - b) / d;
+        else if (g == max)
+            h = 2 + (b - r) / d;
+        else
+            h = 4 + (r - g) / d;
+    }
+
+    BH_ColorSetHSLAf(out, h * 60.0f, s, l, a);
+}
+
+
+static void hslToHsv(const BH_Color *color,
+                     BH_Color *out)
+{
+    float h, s, l, v, a;
+
+    BH_ColorHSLAf(color, &h, &s, &l, &a);
+    v = s * MIN(l, 1.0f - l) + l;
+    s = (v) ? (2.0f - 2.0f * l / v) : (0.0f);
+
+    BH_ColorSetHSVAf(out, h, s, v, a);
+}
+
+
+static void hsvToHsl(const BH_Color *color,
+                     BH_Color *out)
+{
+    float h, s, v, l, a, m;
+
+    BH_ColorHSVAf(color, &h, &s, &v, &a);
+    l = v - v * s / 2.0f;
+    m = MIN(l, 1.0f - l);
+    s = (m) ? ((v - l) / m) : (0);
+    BH_ColorSetHSLAf(out, h, s, l, a);
+}
+
+
+void BH_ColorToRGBA(const BH_Color *color,
+                    BH_Color *out)
+{
+    switch (color->type)
+    {
+    case BH_COLOR_TYPE_RGBA:
+        *out = *color;
+        break;
+
+    case BH_COLOR_TYPE_HSVA:
+        hsvToRgb(color, out);
+        break;
+
+    case BH_COLOR_TYPE_HSLA:
+        hslToHsv(color, out);
+        hsvToRgb(out, out);
+        break;
+    }
+}
+
+
+void BH_ColorToHSVA(const BH_Color *color,
+                    BH_Color *out)
+{
+    switch (color->type)
+    {
+    case BH_COLOR_TYPE_RGBA:
+        rgbToHsv(color, out);
+        break;
+
+    case BH_COLOR_TYPE_HSVA:
+        *out = *color;
+        break;
+
+    case BH_COLOR_TYPE_HSLA:
+        hslToHsv(color, out);
+        break;
+    }
+}
+
+
+void BH_ColorToHSLA(const BH_Color *color,
+                    BH_Color *out)
+{
+    switch (color->type)
+    {
+    case BH_COLOR_TYPE_RGBA:
+        rgbToHsl(color, out);
+        break;
+
+    case BH_COLOR_TYPE_HSVA:
+        hsvToHsl(color, out);
+        break;
+
+    case BH_COLOR_TYPE_HSLA:
+        *out = *color;
+        break;
+    }
+}
+
+
+static float blendNormal(float foreground,
+                         float background)
+{
+    BH_UNUSED(background);
+    return foreground;
+}
+
+
+static float blendMultiply(float foreground,
+                           float background)
+{
+    return foreground * background;
+}
+
+
+static float blendScreen(float foreground,
+                         float background)
+{
+    return foreground + background - (foreground * background);
+}
+
+
+static float blendDarken(float foreground,
+                         float background)
+{
+    return MIN(foreground, background);
+}
+
+
+static float blendLighten(float foreground,
+                          float background)
+{
+    return MAX(foreground, background);
+}
+
+
+static float blendColorDodge(float foreground,
+                             float background)
+{
+    if (foreground != 1.0f)
+        return MIN(1.0f, background / (1.0f - foreground));
+    return foreground;
+}
+
+
+static float blendColorBurn(float foreground,
+                            float background)
+{
+    if (foreground != 0.0f)
+        return 1.0f - MIN(1.0f, (1.0f - background) / foreground);
+    return foreground;
+}
+
+
+static float blendLinearDodge(float foreground,
+                              float background)
+{
+    return foreground + background;
+}
+
+
+static float blendLinearBurn(float foreground,
+                             float background)
+{
+    return foreground + background - 1.0f;
+}
+
+
+static float blendDifference(float foreground,
+                             float background)
+{
+    return fabsf(background - foreground);
+}
+
+
+static float blendExclusion(float foreground,
+                            float background)
+{
+    return foreground + background - (2.0f * foreground * background);
+}
+
+
+static float blendHardLight(float foreground,
+                            float background)
+{
+    if (foreground <= 0.5f)
+        return blendMultiply(2.0f * foreground, background);
+    else
+        return blendScreen(2.0f * foreground - 1.0f, background);
+}
+
+
+static float blendSoftLight(float foreground,
+                            float background)
+{
+    return (1.0f - 2.0f * foreground) * background * background + 2.0f * foreground * background;
+}
+
+
+static float blendOverlay(float foreground,
+                          float background)
+{
+    return blendHardLight(background, foreground);
+}
+
+
+void BH_ColorBlend(const BH_Color *foreground,
+                   const BH_Color *background,
+                   int mode,
+                   BH_Color *dest)
+{
+    float br, bg, bb, ba;
+    float fr, fg, fb, fa;
+
+    if (mode == BH_COLOR_MODE_HUE || mode == BH_COLOR_MODE_SATURATION ||
+        mode == BH_COLOR_MODE_COLOR || mode == BH_COLOR_MODE_LUMINOSITY)
+    {
+        BH_ColorHSLAf(foreground, &fr, &fg, &fb, &fa);
+        BH_ColorHSLAf(background, &br, &bg, &bb, &ba);
+    }
+    else
+    {
+        BH_ColorRGBAf(foreground, &fr, &fg, &fb, &fa);
+        BH_ColorRGBAf(background, &br, &bg, &bb, &ba);
+    }
+
+    switch (mode)
+    {
+    default:
+    case BH_COLOR_MODE_NORMAL:
+        fr = blendNormal(fr, br);
+        fg = blendNormal(fg, bg);
+        fb = blendNormal(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_MULTIPLY:
+        fr = blendMultiply(fr, br);
+        fg = blendMultiply(fg, bg);
+        fb = blendMultiply(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_SCREEN:
+        fr = blendScreen(fr, br);
+        fg = blendScreen(fg, bg);
+        fb = blendScreen(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_OVERLAY:
+        fr = blendOverlay(fr, br);
+        fg = blendOverlay(fg, bg);
+        fb = blendOverlay(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_DARKEN:
+        fr = blendDarken(fr, br);
+        fg = blendDarken(fg, bg);
+        fb = blendDarken(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_LIGHTEN:
+        fr = blendLighten(fr, br);
+        fg = blendLighten(fg, bg);
+        fb = blendLighten(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_COLOR_DODGE:
+        fr = blendColorDodge(fr, br);
+        fg = blendColorDodge(fg, bg);
+        fb = blendColorDodge(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_COLOR_BURN:
+        fr = blendColorBurn(fr, br);
+        fg = blendColorBurn(fg, bg);
+        fb = blendColorBurn(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_LINEAR_DODGE:
+        fr = blendLinearDodge(fr, br);
+        fg = blendLinearDodge(fg, bg);
+        fb = blendLinearDodge(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_LINEAR_BURN:
+        fr = blendLinearBurn(fr, br);
+        fg = blendLinearBurn(fg, bg);
+        fb = blendLinearBurn(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_HARD_LIGHT:
+        fr = blendHardLight(fr, br);
+        fg = blendHardLight(fg, bg);
+        fb = blendHardLight(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_SOFT_LIGHT:
+        fr = blendSoftLight(fr, br);
+        fg = blendSoftLight(fg, bg);
+        fb = blendSoftLight(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_DIFFERENCE:
+        fr = blendDifference(fr, br);
+        fg = blendDifference(fg, bg);
+        fb = blendDifference(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_EXCLUSION:
+        fr = blendExclusion(fr, br);
+        fg = blendExclusion(fg, bg);
+        fb = blendExclusion(fb, bb);
+        BH_ColorSetRGBAf(dest, fr, fg, fb, fa);
+        break;
+
+    case BH_COLOR_MODE_HUE:
+        BH_ColorSetHSLAf(dest, fr, bg, bb, fa);
+        break;
+
+    case BH_COLOR_MODE_SATURATION:
+        BH_ColorSetHSLAf(dest, br, fg, bb, fa);
+        break;
+
+    case BH_COLOR_MODE_COLOR:
+        BH_ColorSetHSLAf(dest, fr, fg, bb, fa);
+        break;
+
+    case BH_COLOR_MODE_LUMINOSITY:
+        BH_ColorSetHSLAf(dest, br, bg, fb, fa);
+        break;
+    }
+}