Colour Management

- 1st stage: Linear Workflow

This implements automatic linear workflow in Blender's renderer. With the 
new Colour Management option on in the Render buttons, all inputs to the 
renderer and compositor are converted to linear colour space before 
rendering, and gamma corrected afterwards. In essence, this makes all 
manual gamma correction with nodes, etc unnecessary, since it's done 
automatically through the pipeline.

It's all explained much better in the notes/doc here, so please have a look:
http://wiki.blender.org/index.php/Dev:Source/Blender/Architecture/Colour_Management

And an example of the sort of difference it makes:
http://mke3.net/blender/devel/rendering/b25_colormanagement_test01.jpg

This also enables Colour Management in the default B.blend, and changes the 
default lamp falloff to inverse square, which is more correct, and much 
easier to use now it's all gamma corrected properly.

Next step is to look into profiles/soft proofing for the compositor.

Thanks to brecht for reviewing and fixing some oversights!

1 files changed, 17 insertions, 1 deletions

diff --git a/source/blender/imbuf/IMB_imbuf_types.h b/source/blender/imbuf/IMB_imbuf_types.h
index 79da0cb1c41..91a7b136fa5 100644
--- a/source/blender/imbuf/IMB_imbuf_types.h
+++ b/source/blender/imbuf/IMB_imbuf_types.h
@@ -98,9 +98,13 @@ typedef struct ImBuf {
 	unsigned int   encodedsize;       /**< Size of data written to encodedbuffer */
 	unsigned int   encodedbuffersize; /**< Size of encodedbuffer */
 
-	float *rect_float;		/**< floating point Rect equivalent */
+	float *rect_float;		/**< floating point Rect equivalent
+								Linear RGB color space - may need gamma correction to 
+								sRGB when generating 8bit representations */
 	int channels;			/**< amount of channels in rect_float (0 = 4 channel default) */
 	float dither;			/**< random dither value, for conversion from float -> byte rect */
+	short profile;			/** color space/profile preset that the byte rect buffer represents */
+	char profile_filename[256];		/** to be implemented properly, specific filename for custom profiles */
 	
 	struct MEM_CacheLimiterHandle_s * c_handle; /**< handle for cache limiter */
 	struct ImgInfo * img_info;
@@ -213,6 +217,18 @@ typedef enum {
 #define AN_tanx			(Anim | TANX)
 /**@}*/
 
+/**
+ * \name Imbuf preset profile tags
+ * \brief Some predefined color space profiles that 8 bit imbufs can represent
+ */
+/**@{*/
+#define IB_PROFILE_NONE			0
+#define IB_PROFILE_LINEAR_RGB	1
+#define IB_PROFILE_SRGB			2
+#define IB_PROFILE_CUSTOM		3
+/**@}*/
+
+
 /** \name Imbuf File Type Tests
  * \brief These macros test if an ImBuf struct is the corresponding file type.
  */