Improvements to Blenders color balance (lift/gamma/gain).

Fairly closely match some mac application colin has called 'Looks', to give better results.
- lift is now applied non linear (was being added to the color)
- change the color wheel to preserve the luminance of the gamma and gain values, this stops the color from being set too dark (option for the color wheel template).
- sub-pixel precission for the color wheel since the white area at the center can make a lot of difference with a very small change.

This change will make existing node and sequencer setups lift render slighly differently however discussed this with Ton and he's ok with it.

10 files changed, 60 insertions, 28 deletions

diff --git a/release/scripts/ui/properties_physics_common.py b/release/scripts/ui/properties_physics_common.py
index 5b4c07642b4..6d97e82ff41 100644
--- a/release/scripts/ui/properties_physics_common.py
+++ b/release/scripts/ui/properties_physics_common.py
@@ -38,7 +38,7 @@ def point_cache_ui(self, context, cache, enabled, cachetype):
     col.operator("ptcache.remove", icon='ZOOMOUT', text="")
 
     row = layout.row()
-    if cachetype in {'PSYS', 'HAIR', 'SMOKE'}:
+    if cachetype in ('PSYS', 'HAIR', 'SMOKE'):
         row.prop(cache, "external")
 
     if cache.external:
diff --git a/release/scripts/ui/space_sequencer.py b/release/scripts/ui/space_sequencer.py
index ed39a98e86a..03e692693d8 100644
--- a/release/scripts/ui/space_sequencer.py
+++ b/release/scripts/ui/space_sequencer.py
@@ -753,11 +753,11 @@ class SEQUENCER_PT_filter(SequencerButtonsPanel):
             col.row().prop(strip.color_balance, "lift")
             col.prop(strip.color_balance, "inverse_lift", text="Inverse")
             col = row.column()
-            col.template_color_wheel(strip.color_balance, "gamma", value_slider=False)
+            col.template_color_wheel(strip.color_balance, "gamma", value_slider=False, lock_luminosity=True)
             col.row().prop(strip.color_balance, "gamma")
             col.prop(strip.color_balance, "inverse_gamma", text="Inverse")
             col = row.column()
-            col.template_color_wheel(strip.color_balance, "gain", value_slider=False)
+            col.template_color_wheel(strip.color_balance, "gain", value_slider=False, lock_luminosity=True)
             col.row().prop(strip.color_balance, "gain")
             col.prop(strip.color_balance, "inverse_gain", text="Inverse")
 
diff --git a/source/blender/blenkernel/intern/sequencer.c b/source/blender/blenkernel/intern/sequencer.c
index e21901f70d9..28cae5eeaa6 100644
--- a/source/blender/blenkernel/intern/sequencer.c
+++ b/source/blender/blenkernel/intern/sequencer.c
@@ -49,6 +49,7 @@
 #include "RNA_access.h"
 #include "RE_pipeline.h"
 
+#include "BLI_math.h"
 #include "BLI_fileops.h"
 #include "BLI_listbase.h"
 #include "BLI_path_util.h"
@@ -1528,32 +1529,35 @@ static void make_cb_table_byte(float lift, float gain, float gamma,
 				   unsigned char * table, float mul)
 {
 	int y;
+	/* matches 'LooksBuilder', generally looks nice too */
+	if(lift >= 1.0f)	lift= 0.0f;
+	else lift=			(1.0f - lift) * (1.0f - lift);
+	/* end modif's */
 
 	for (y = 0; y < 256; y++) {
-			float v = 1.0 * y / 255;
+		float v = (float)y * (1.0 / 255.0f);
 		v *= gain;
-		v += lift; 
+		v = pow(v, lift);
 		v = pow(v, gamma);
 		v *= mul;
-		if ( v > 1.0) {
-			v = 1.0;
-		} else if (v < 0.0) {
-			v = 0.0;
-		}
+		CLAMP(v, 0.0f, 1.0f);
 		table[y] = v * 255;
 	}
-
 }
 
 static void make_cb_table_float(float lift, float gain, float gamma,
 				float * table, float mul)
 {
 	int y;
+	/* matches 'LooksBuilder', generally looks nice too */
+	if(lift >= 1.0f)	lift= 0.0f;
+	else lift=			(1.0f - lift) * (1.0f - lift);
+	/* end modif's */
 
 	for (y = 0; y < 256; y++) {
-			float v = (float) y * 1.0 / 255.0;
+		float v = (float)y * (1.0 / 255.0f);
 		v *= gain;
-		v += lift;
+		v = pow(v, lift);
 		v = pow(v, gamma);
 		v *= mul;
 		table[y] = v;
diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 35531a2a029..fea8c32b43b 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -152,6 +152,8 @@ typedef struct uiLayout uiLayout;
 #define UI_BUT_IMMEDIATE	(1<<26)
 #define UI_BUT_NO_TOOLTIP	(1<<27)
 
+#define UI_BUT_VEC_SIZE_LOCK (1<<28) /* used to flag if color hsv-circle should keep luminance */
+
 #define UI_PANEL_WIDTH			340
 #define UI_COMPACT_PANEL_WIDTH	160
 
@@ -683,7 +685,7 @@ void uiTemplateHistogram(uiLayout *layout, struct PointerRNA *ptr, char *propnam
 void uiTemplateWaveform(uiLayout *layout, struct PointerRNA *ptr, char *propname, int expand);
 void uiTemplateVectorscope(uiLayout *layout, struct PointerRNA *ptr, char *propname, int expand);
 void uiTemplateCurveMapping(uiLayout *layout, struct PointerRNA *ptr, char *propname, int type, int levels, int brush);
-void uiTemplateColorWheel(uiLayout *layout, struct PointerRNA *ptr, char *propname, int value_slider, int lock);
+void uiTemplateColorWheel(uiLayout *layout, struct PointerRNA *ptr, char *propname, int value_slider, int lock, int lock_luminosity);
 void uiTemplateTriColorSet(uiLayout *layout, struct PointerRNA *ptr, char *propname);
 void uiTemplateLayers(uiLayout *layout, struct PointerRNA *ptr, char *propname,
 			  PointerRNA *used_ptr, char *used_propname, int active_layer);
diff --git a/source/blender/editors/interface/interface_handlers.c b/source/blender/editors/interface/interface_handlers.c
index eda7102e69b..999b92e6854 100644
--- a/source/blender/editors/interface/interface_handlers.c
+++ b/source/blender/editors/interface/interface_handlers.c
@@ -236,7 +236,7 @@ static uiBut *ui_but_last(uiBlock *block)
 static int ui_is_a_warp_but(uiBut *but)
 {
 	if(U.uiflag & USER_CONTINUOUS_MOUSE)
-		if(ELEM(but->type, NUM, NUMABS))
+		if(ELEM3(but->type, NUM, NUMABS, HSVCIRCLE))
 			return TRUE;
 
 	return FALSE;
@@ -3064,10 +3064,22 @@ static int ui_numedit_but_HSVCIRCLE(uiBut *but, uiHandleButtonData *data, int mx
 	if (but->a2 == 1) { // lock
 		if (hsv[2] == 0.f) hsv[2] = 0.0001f;
 	}
+
+	if(U.uiflag & USER_CONTINUOUS_MOUSE) {
+		/* slow down the mouse, this is fairly picky */
+		mx = (data->dragstartx*0.9 + mx*0.1);
+		my = (data->dragstarty*0.9 + my*0.1);
+	}
 		
 	ui_hsvcircle_vals_from_pos(hsv, hsv+1, &rect, (float)mx, (float)my);
 	
 	hsv_to_rgb(hsv[0], hsv[1], hsv[2], rgb, rgb+1, rgb+2);
+
+	if(but->flag & UI_BUT_VEC_SIZE_LOCK) {
+		normalize_v3(rgb);
+		mul_v3_fl(rgb, but->color_lum);
+	}
+
 	ui_set_but_vectorf(but, rgb);
 	
 	data->draglastx= mx;
diff --git a/source/blender/editors/interface/interface_intern.h b/source/blender/editors/interface/interface_intern.h
index ecefcf93c28..078e337f8f9 100644
--- a/source/blender/editors/interface/interface_intern.h
+++ b/source/blender/editors/interface/interface_intern.h
@@ -173,6 +173,7 @@ struct uiBut {
 	float hardmin, hardmax, softmin, softmax;
 	float a1, a2, hsv[3];	// hsv is temp memory for hsv buttons
 	float aspect;
+	float color_lum; /* used only for color buttons so far */
 
 	uiButHandleFunc func;
 	void *func_arg1;
@@ -184,8 +185,11 @@ struct uiBut {
 
 	struct bContextStore *context;
 
+	/* not ysed yet, was used in 2.4x for ui_draw_pulldown_round & friends */
+	/*
 	void (*embossfunc)(int , int , float, float, float, float, float, int);
 	void (*sliderfunc)(int , float, float, float, float, float, float, int);
+	*/
 
 	uiButCompleteFunc autocomplete_func;
 	void *autofunc_arg;
@@ -228,12 +232,12 @@ struct uiBut {
 
 	/* Operator data */
 	struct wmOperatorType *optype;
-	int opcontext;
 	struct IDProperty *opproperties;
 	struct PointerRNA *opptr;
+	short opcontext;
 	
 	/* Draggable data, type is WM_DRAG_... */
-	int dragtype;
+	short dragtype;
 	void *dragpoin;
 	struct ImBuf *imb;
 	float imb_scale;
diff --git a/source/blender/editors/interface/interface_templates.c b/source/blender/editors/interface/interface_templates.c
index dbe64bedbc6..261f83f9bbc 100644
--- a/source/blender/editors/interface/interface_templates.c
+++ b/source/blender/editors/interface/interface_templates.c
@@ -1949,11 +1949,12 @@ void uiTemplateCurveMapping(uiLayout *layout, PointerRNA *ptr, char *propname, i
 
 #define WHEEL_SIZE	100
 
-void uiTemplateColorWheel(uiLayout *layout, PointerRNA *ptr, char *propname, int value_slider, int lock)
+void uiTemplateColorWheel(uiLayout *layout, PointerRNA *ptr, char *propname, int value_slider, int lock, int lock_luminosity)
 {
 	PropertyRNA *prop= RNA_struct_find_property(ptr, propname);
 	uiBlock *block= uiLayoutGetBlock(layout);
 	uiLayout *col, *row;
+	uiBut *but;
 	float softmin, softmax, step, precision;
 	
 	if (!prop) {
@@ -1966,8 +1967,15 @@ void uiTemplateColorWheel(uiLayout *layout, PointerRNA *ptr, char *propname, int
 	col = uiLayoutColumn(layout, 0);
 	row= uiLayoutRow(col, 1);
 	
-	uiDefButR(block, HSVCIRCLE, 0, "",	0, 0, WHEEL_SIZE, WHEEL_SIZE, ptr, propname, -1, 0.0, 0.0, 0, lock, "");
-	
+	but= uiDefButR(block, HSVCIRCLE, 0, "",	0, 0, WHEEL_SIZE, WHEEL_SIZE, ptr, propname, -1, 0.0, 0.0, 0, lock, "");
+
+	if(lock_luminosity) {
+		float color[4]; /* incase of alpha */
+		but->flag |= UI_BUT_VEC_SIZE_LOCK;
+		RNA_property_float_get_array(ptr, prop, color);
+		but->color_lum= len_v3(color); /* abuse the soft-max though this is a kind of soft-max */
+	}
+
 	uiItemS(row);
 	
 	if (value_slider)
diff --git a/source/blender/editors/interface/interface_widgets.c b/source/blender/editors/interface/interface_widgets.c
index 2cfdf2d5e04..b7a1874cd2b 100644
--- a/source/blender/editors/interface/interface_widgets.c
+++ b/source/blender/editors/interface/interface_widgets.c
@@ -1674,6 +1674,7 @@ void ui_draw_but_HSVCIRCLE(uiBut *but, uiWidgetColors *wcol, rcti *rect)
 		float co= cos(ang);
 		
 		ui_hsvcircle_vals_from_pos(hsv, hsv+1, rect, centx + co*radius, centy + si*radius);
+		CLAMP(hsv[2], 0.0f, 1.0f); /* for display only */
 		hsv_to_rgb(hsv[0], hsv[1], hsv[2], col, col+1, col+2);
 		glColor3fv(col);
 		glVertex2f( centx + co*radius, centy + si*radius);
@@ -1688,7 +1689,7 @@ void ui_draw_but_HSVCIRCLE(uiBut *but, uiWidgetColors *wcol, rcti *rect)
 	glEnable(GL_BLEND);
 	glEnable(GL_LINE_SMOOTH );
 	glColor3ubv((unsigned char*)wcol->outline);
-	glutil_draw_lined_arc(0.0f, M_PI*2.0, radius, tot);
+	glutil_draw_lined_arc(0.0f, M_PI*2.0, radius, tot + 1);
 	glDisable(GL_BLEND);
 	glDisable(GL_LINE_SMOOTH );
 	glPopMatrix();
diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index 629b1008aa0..7b4584da3ab 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -107,7 +107,7 @@ static void node_buts_rgb(uiLayout *layout, bContext *C, PointerRNA *ptr)
 	RNA_property_collection_lookup_int(ptr, prop, 0, &sockptr);
 	
 	col = uiLayoutColumn(layout, 0);
-	uiTemplateColorWheel(col, &sockptr, "default_value", 1, 0);
+	uiTemplateColorWheel(col, &sockptr, "default_value", 1, 0, 0);
 	uiItemR(col, &sockptr, "default_value", 0, "", 0);
 }
 
@@ -947,17 +947,17 @@ static void node_composit_buts_colorbalance(uiLayout *layout, bContext *C, Point
 	
 		split = uiLayoutSplit(layout, 0, 0);
 		col = uiLayoutColumn(split, 0);
-		uiTemplateColorWheel(col, ptr, "lift", 1, 1);
+		uiTemplateColorWheel(col, ptr, "lift", 1, 1, 0);
 		row = uiLayoutRow(col, 0);
 		uiItemR(row, ptr, "lift", 0, NULL, 0);
 		
 		col = uiLayoutColumn(split, 0);
-		uiTemplateColorWheel(col, ptr, "gamma", 1, 1);
+		uiTemplateColorWheel(col, ptr, "gamma", 1, 1, 1);
 		row = uiLayoutRow(col, 0);
 		uiItemR(row, ptr, "gamma", 0, NULL, 0);
 		
 		col = uiLayoutColumn(split, 0);
-		uiTemplateColorWheel(col, ptr, "gain", 1, 1);
+		uiTemplateColorWheel(col, ptr, "gain", 1, 1, 1);
 		row = uiLayoutRow(col, 0);
 		uiItemR(row, ptr, "gain", 0, NULL, 0);
 
@@ -965,17 +965,17 @@ static void node_composit_buts_colorbalance(uiLayout *layout, bContext *C, Point
 		
 		split = uiLayoutSplit(layout, 0, 0);
 		col = uiLayoutColumn(split, 0);
-		uiTemplateColorWheel(col, ptr, "offset", 1, 1);
+		uiTemplateColorWheel(col, ptr, "offset", 1, 1, 0);
 		row = uiLayoutRow(col, 0);
 		uiItemR(row, ptr, "offset", 0, NULL, 0);
 		
 		col = uiLayoutColumn(split, 0);
-		uiTemplateColorWheel(col, ptr, "power", 1, 1);
+		uiTemplateColorWheel(col, ptr, "power", 1, 1, 0);
 		row = uiLayoutRow(col, 0);
 		uiItemR(row, ptr, "power", 0, NULL, 0);
 		
 		col = uiLayoutColumn(split, 0);
-		uiTemplateColorWheel(col, ptr, "slope", 1, 1);
+		uiTemplateColorWheel(col, ptr, "slope", 1, 1, 0);
 		row = uiLayoutRow(col, 0);
 		uiItemR(row, ptr, "slope", 0, NULL, 0);
 	}
diff --git a/source/blender/makesrna/intern/rna_ui_api.c b/source/blender/makesrna/intern/rna_ui_api.c
index 16864985289..6cf0768b192 100644
--- a/source/blender/makesrna/intern/rna_ui_api.c
+++ b/source/blender/makesrna/intern/rna_ui_api.c
@@ -360,6 +360,7 @@ void RNA_api_ui_layout(StructRNA *srna)
 	api_ui_item_rna_common(func);
 	RNA_def_boolean(func, "value_slider", 0, "", "Display the value slider to the right of the color wheel");
 	RNA_def_boolean(func, "lock", 0, "", "Lock the color wheel display to value 1.0 regardless of actual color");
+	RNA_def_boolean(func, "lock_luminosity", 0, "", "Keep the color at its original vector length");
 	
 	func= RNA_def_function(srna, "template_triColorSet", "uiTemplateTriColorSet");
 	api_ui_item_rna_common(func);