@@ -348,7 +348,7 @@ DATA32 *data = imlib_image_get_data();
 		adjust_asb(data,
 				   icon_size,
 				   icon_size,
-				   launcher_alpha,
+				   launcher_alpha / 100.0,
 				   launcher_saturation / 100.0,
 				   launcher_brightness / 100.0);
 		imlib_image_put_back_data(data);

@@ -1338,7 +1338,7 @@ if (systray.alpha != 100 || systray.brightness != 0 || systray.saturation != 0)
 		adjust_asb(data,
 		           traywin->width,
 		           traywin->height,
-		           systray.alpha,
+				   systray.alpha / 100.0,
 				   systray.saturation / 100.0,
 				   systray.brightness / 100.0);
 	imlib_image_put_back_data(data);

@@ -315,7 +315,7 @@ data32 = imlib_image_get_data();
 			adjust_asb(data32,
 					   task->icon_width,
 					   task->icon_height,
-					   panel->g_task.alpha[k],
+					   panel->g_task.alpha[k] / 100.0,
 					   panel->g_task.saturation[k] / 100.0,
 					   panel->g_task.brightness[k] / 100.0);
 			imlib_image_put_back_data(data32);

@@ -238,128 +238,110 @@ g_strstrip(*value3);
 	}
 }
 
-void adjust_asb(DATA32 *data, int w, int h, int alpha, float satur, float bright)
+void adjust_asb(DATA32 *data, int w, int h, float alpha_adjust, float satur_adjust, float bright_adjust)
 {
-	unsigned int x, y;
-	unsigned int argb;
-	int a, r, g, b;
-	unsigned long id;
-	int cmax, cmin;
-	float h2, f, p, q, t;
-	float hue, saturation, brightness;
-	float redc, greenc, bluec;
-
-	for (y = 0; y < h; y++) {
-		for (id = y * w, x = 0; x < w; x++, id++) {
-			argb = data[id];
-			a = (argb >> 24) & 0xff;
-			// transparent => nothing to do.
-			if (a == 0)
-				continue;
-			r = (argb >> 16) & 0xff;
-			g = (argb >> 8) & 0xff;
-			b = (argb)&0xff;
+	for (int id = 0; id < w * h; id++) {
+		unsigned int argb = data[id];
+		int a = (argb >> 24) & 0xff;
+		// transparent => nothing to do.
+		if (a == 0)
+			continue;
+		int r = (argb >> 16) & 0xff;
+		int g = (argb >> 8) & 0xff;
+		int b = (argb) & 0xff;
 
-			// convert RGB to HSB
-			cmax = (r > g) ? r : g;
-			if (b > cmax)
-				cmax = b;
-			cmin = (r < g) ? r : g;
-			if (b < cmin)
-				cmin = b;
-			brightness = ((float)cmax) / 255.0f;
-			if (cmax != 0)
-				saturation = ((float)(cmax - cmin)) / ((float)cmax);
+		// Convert RGB to HSV
+		int cmax = MAX3(r, g, b);
+		int cmin = MIN3(r, g, b);
+		int delta = cmax - cmin;
+		float brightness = cmax / 255.0f;
+		float saturation;
+		if (cmax != 0)
+			saturation = delta / (float)cmax;
+		else
+			saturation = 0;
+		float hue;
+		if (saturation == 0) {
+			hue = 0;
+		} else {
+			float redc = (cmax - r) / (float)delta;
+			float greenc = (cmax - g) / (float)delta;
+			float bluec = (cmax - b) / (float)delta;
+			if (r == cmax)
+				hue = bluec - greenc;
+			else if (g == cmax)
+				hue = 2.0f + redc - bluec;
 			else
-				saturation = 0;
-			if (saturation == 0)
-				hue = 0;
-			else {
-				redc = ((float)(cmax - r)) / ((float)(cmax - cmin));
-				greenc = ((float)(cmax - g)) / ((float)(cmax - cmin));
-				bluec = ((float)(cmax - b)) / ((float)(cmax - cmin));
-				if (r == cmax)
-					hue = bluec - greenc;
-				else if (g == cmax)
-					hue = 2.0f + redc - bluec;
-				else
-					hue = 4.0f + greenc - redc;
-				hue = hue / 6.0f;
-				if (hue < 0)
-					hue = hue + 1.0f;
-			}
+				hue = 4.0f + greenc - redc;
+			hue = hue / 6.0f;
+			if (hue < 0)
+				hue = hue + 1.0f;
+		}
 
-			// adjust
-			saturation += satur;
-			if (saturation < 0.0)
-				saturation = 0.0;
-			if (saturation > 1.0)
-				saturation = 1.0;
-			//brightness += bright;
-			if (brightness < 0.0)
-				brightness = 0.0;
-			if (brightness > 1.0)
-				brightness = 1.0;
-			if (alpha != 100)
-				a = (a * alpha) / 100;
+		// Adjust H, S
+		saturation += satur_adjust;
+		saturation = CLAMP(saturation, 0.0, 1.0);
 
-			// convert HSB to RGB
-			if (saturation == 0) {
-				r = g = b = (int)(brightness * 255.0f + 0.5f);
-			} else {
-				h2 = (hue - (int)hue) * 6.0f;
-				f = h2 - (int)(h2);
-				p = brightness * (1.0f - saturation);
-				q = brightness * (1.0f - saturation * f);
-				t = brightness * (1.0f - (saturation * (1.0f - f)));
-				switch ((int)h2) {
-				case 0:
-					r = (int)(brightness * 255.0f + 0.5f);
-					g = (int)(t * 255.0f + 0.5f);
-					b = (int)(p * 255.0f + 0.5f);
-					break;
-				case 1:
-					r = (int)(q * 255.0f + 0.5f);
-					g = (int)(brightness * 255.0f + 0.5f);
-					b = (int)(p * 255.0f + 0.5f);
-					break;
-				case 2:
-					r = (int)(p * 255.0f + 0.5f);
-					g = (int)(brightness * 255.0f + 0.5f);
-					b = (int)(t * 255.0f + 0.5f);
-					break;
-				case 3:
-					r = (int)(p * 255.0f + 0.5f);
-					g = (int)(q * 255.0f + 0.5f);
-					b = (int)(brightness * 255.0f + 0.5f);
-					break;
-				case 4:
-					r = (int)(t * 255.0f + 0.5f);
-					g = (int)(p * 255.0f + 0.5f);
-					b = (int)(brightness * 255.0f + 0.5f);
-					break;
-				case 5:
-					r = (int)(brightness * 255.0f + 0.5f);
-					g = (int)(p * 255.0f + 0.5f);
-					b = (int)(q * 255.0f + 0.5f);
-					break;
-				}
+		a *= alpha_adjust;
+		a = CLAMP(a, 0, 255);
+
+		// Convert HSV to RGB
+		if (saturation == 0) {
+			r = g = b = (int)(brightness * 255.0f + 0.5f);
+		} else {
+			float h2 = (hue - (int)hue) * 6.0f;
+			float f = h2 - (int)(h2);
+			float p = brightness * (1.0f - saturation);
+			float q = brightness * (1.0f - saturation * f);
+			float t = brightness * (1.0f - (saturation * (1.0f - f)));
+
+			switch ((int)h2) {
+			case 0:
+				r = (int)(brightness * 255.0f + 0.5f);
+				g = (int)(t * 255.0f + 0.5f);
+				b = (int)(p * 255.0f + 0.5f);
+				break;
+			case 1:
+				r = (int)(q * 255.0f + 0.5f);
+				g = (int)(brightness * 255.0f + 0.5f);
+				b = (int)(p * 255.0f + 0.5f);
+				break;
+			case 2:
+				r = (int)(p * 255.0f + 0.5f);
+				g = (int)(brightness * 255.0f + 0.5f);
+				b = (int)(t * 255.0f + 0.5f);
+				break;
+			case 3:
+				r = (int)(p * 255.0f + 0.5f);
+				g = (int)(q * 255.0f + 0.5f);
+				b = (int)(brightness * 255.0f + 0.5f);
+				break;
+			case 4:
+				r = (int)(t * 255.0f + 0.5f);
+				g = (int)(p * 255.0f + 0.5f);
+				b = (int)(brightness * 255.0f + 0.5f);
+				break;
+			case 5:
+				r = (int)(brightness * 255.0f + 0.5f);
+				g = (int)(p * 255.0f + 0.5f);
+				b = (int)(q * 255.0f + 0.5f);
+				break;
 			}
+		}
 
-			r += bright * 255;
-			g += bright * 255;
-			b += bright * 255;
+		r += bright_adjust * 255;
+		g += bright_adjust * 255;
+		b += bright_adjust * 255;
 
-			r = MAX(0, MIN(255, r));
-			g = MAX(0, MIN(255, g));
-			b = MAX(0, MIN(255, b));
+		r = CLAMP(r, 0, 255);
+		g = CLAMP(g, 0, 255);
+		b = CLAMP(b, 0, 255);
 
-			argb = a;
-			argb = (argb << 8) + r;
-			argb = (argb << 8) + g;
-			argb = (argb << 8) + b;
-			data[id] = argb;
-		}
+		argb = a;
+		argb = (argb << 8) + r;
+		argb = (argb << 8) + g;
+		argb = (argb << 8) + b;
+		data[id] = argb;
 	}
 }
 
@@ -511,7 +493,7 @@ DATA32 *data = imlib_image_get_data();
 	adjust_asb(data,
 			   imlib_image_get_width(),
 			   imlib_image_get_height(),
-			   alpha,
+			   alpha / 100.0,
 			   saturation / 100.0,
 			   brightness / 100.0);
 	imlib_image_put_back_data(data);

@@ -8,6 +8,7 @@ #define COMMON_H
 
 #define WM_CLASS_TINT "panel"
 
+#include <glib.h>
 #include <Imlib2.h>
 #include <pango/pangocairo.h>
 #include "area.h"
@@ -17,6 +18,9 @@ #define YELLOW "\033[1;33m"
 #define RED    "\033[1;31m"
 #define BLUE   "\033[1;34m"
 #define RESET  "\033[0m"
+
+#define MAX3(a, b, c)  MAX(MAX(a, b), c)
+#define MIN3(a, b, c)  MIN(MIN(a, b), c)
 
 // mouse actions
 typedef enum MouseAction {
@@ -67,8 +71,20 @@
 Imlib_Image load_image(const char *path, int cached);
 
 // Adjusts the alpha/saturation/brightness on an ARGB image.
-// Parameters: alpha from 0 to 100, satur from 0 to 1, bright from 0 to 1.
-void adjust_asb(DATA32 *data, int w, int h, int alpha, float satur, float bright);
+// Parameters:
+// * alpha_adjust: multiplicative:
+//    * 0 = full transparency
+//    * 1 = no adjustment
+//    * 2 = twice the current opacity
+// * satur_adjust: additive:
+//   * -1 = full grayscale
+//   *  0 = no adjustment
+//   *  1 = full color
+// * bright_adjust: additive:
+//   * -1 = black
+//   *  0 = no adjustment
+//   *  1 = white
+void adjust_asb(DATA32 *data, int w, int h, float alpha_adjust, float satur_adjust, float bright_adjust);
 Imlib_Image adjust_icon(Imlib_Image original, int alpha, int saturation, int brightness);
 
 void create_heuristic_mask(DATA32 *data, int w, int h);