* Extra lamp falloff options, including custom curve!

This adds some new lamp attenuation options to the Lamp panel, replacing the old 'Quad' button. Yes, the panel layout is still nasty here, but I've ignored it for now to address properly in the panels cleanup work.

* Constant
http://mke3.net/blender/devel/rendering/falloff-constant.jpg
Lamp doesn't decay with distance

* Inverse Linear
http://mke3.net/blender/devel/rendering/falloff-invlinear.jpg
Default, and same as in older Blender without 'Quad' on. Decays linearly, with 'Dist' value as the lamp's half-energy-distance

* Inverse Square
http://mke3.net/blender/devel/rendering/falloff-invsquare.jpg
A sharper, more realistic decay, good for most electric lights (i.e. not sunlight). This is similar to the old Quad option with slight changes.

* Lin/Quad weighted
Exactly the same as in older Blenders with the old 'Quad' button enabled. When this setting is chosen, two sliders are shown, 'Linear' and 'Quad' (previously Quad1 and Quad2), which controls the 'linearness' or 'quadraticness' of the falloff curve. Lamps in old files with the 'Quad' button on will be initialised to this setting.

But much better for precise control over the lamp falloff now is:

* Custom Curve
This shows an extra 'Falloff Curve' panel, where you can use the standard Blender curve UI control to precisely control how the light falls off. The Y axis is intensity, and the X axis is distance, stretched over the length of the 'Dist' value.

Some example curves and renders:
http://mke3.net/blender/devel/rendering/falloff-curve1-curve.png
http://mke3.net/blender/devel/rendering/falloff-curve1.jpg

http://mke3.net/blender/devel/rendering/falloff-curve2-curve.png
http://mke3.net/blender/devel/rendering/falloff-curve2.jpg

http://mke3.net/blender/devel/rendering/falloff-curve3-curve.png
http://mke3.net/blender/devel/rendering/falloff-curve3.jpg (whee)

1 files changed, 16 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_lamp_types.h b/source/blender/makesdna/DNA_lamp_types.h
index e1d4e4c1cc1..f8cc2378cb1 100644
--- a/source/blender/makesdna/DNA_lamp_types.h
+++ b/source/blender/makesdna/DNA_lamp_types.h
@@ -43,6 +43,7 @@
 
 struct MTex;
 struct Ipo;
+struct CurveMapping;
 
 typedef struct Lamp {
 	ID id;
@@ -54,7 +55,13 @@ typedef struct Lamp {
 	
 	float energy, dist, spotsize, spotblend;
 	float haint;
+	
+	
 	float att1, att2;	/* Quad1 and Quad2 attenuation */
+	int pad2;
+	struct CurveMapping *curfalloff;
+	short falloff_type;
+	short pad3;
 	
 	float clipsta, clipend, shadspotsize;
 	float bias, soft;
@@ -104,7 +111,7 @@ typedef struct Lamp {
 #define LA_SHAD_BUF		1
 #define LA_HALO			2
 #define LA_LAYER		4
-#define LA_QUAD			8
+#define LA_QUAD			8	/* no longer used */
 #define LA_NEG			16
 #define LA_ONLYSHADOW	32
 #define LA_SPHERE		64
@@ -119,6 +126,14 @@ typedef struct Lamp {
 /* Since it is used with LOCAL lamp, can't use LA_SHAD */
 #define LA_YF_SOFT		16384
 
+/* falloff_type */
+#define LA_FALLOFF_CONSTANT		0
+#define LA_FALLOFF_INVLINEAR		1
+#define LA_FALLOFF_INVSQUARE	2
+#define LA_FALLOFF_CURVE		3
+#define LA_FALLOFF_SLIDERS		4
+
+
 /* buftype, no flag */
 #define LA_SHADBUF_REGULAR		0
 #define LA_SHADBUF_IRREGULAR	1