Durian request: Added 'Color Balance' node to compositor. uses Lift/Gamma/Gain

similar to sequence editor.

--> http://mke3.net/blender/devel/2.5/color_balance_node.jpg

Also added 0 key (zero key) shortcut when mouse is over a button, to reset it to its default value.
Same as the RMB menu ->Reset to Default, except for color wheels, it only resets the hue/sat/value
components that that widget affects.

Peter/Xavier: The existing color balance code can generate NaNs (fractional power of a negative),
which causes havoc along the image pipeline. I added a check in the node code to prevent this.

Still plenty of potential for lots of better colour correction tools in the compositor, just needs time...

2 files changed, 52 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index 2105e10bbd1..d151e911a9c 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -42,6 +42,8 @@
 #include "BKE_image.h"
 #include "BKE_texture.h"
 
+#include "BLI_math.h"
+
 #include "WM_types.h"
 
 #include "MEM_guardedalloc.h"
@@ -298,6 +300,23 @@ static void rna_Node_image_layer_update(Main *bmain, Scene *scene, PointerRNA *p
 	rna_Node_update(bmain, scene, ptr);
 }
 
+static void rna_Node_colorbalance_update(Main *bmain, Scene *scene, PointerRNA *ptr)
+{
+	bNode *node= (bNode*)ptr->data;
+	NodeColorBalance *ncb = node->storage;
+	float lift[3], gamma[3], gain[3];
+	float n_one[3] = {-1.f, -1.f, -1.f};
+	
+	mul_v3_v3fl(lift, ncb->lift, 2.f);
+	add_v3_v3(lift, n_one);
+	mul_v3_v3fl(gamma, ncb->gamma, 2.f);
+	mul_v3_v3fl(gain, ncb->gain, 2.f);
+	
+	lift_gamma_gain_to_asc_cdl(lift, gamma, gain, ncb->offset, ncb->slope, ncb->power);
+	
+	rna_Node_update(bmain, scene, ptr);
+}
+
 static EnumPropertyItem *renderresult_layers_add_enum(RenderLayer *rl)
 {
 	EnumPropertyItem *item= NULL;
@@ -1854,6 +1873,38 @@ static void def_cmp_lensdist(StructRNA *srna)
 	RNA_def_property_ui_text(prop, "Fit", "For positive distortion factor only: scale image such that black areas are not visible");
 	RNA_def_property_update(prop, NC_NODE|NA_EDITED, "rna_Node_update");
 }
+
+static void def_cmp_colorbalance(StructRNA *srna)
+{
+	PropertyRNA *prop;
+	static float default_col[3] = {0.5f, 0.5f, 0.5f};
+	
+	RNA_def_struct_sdna_from(srna, "NodeColorBalance", "storage");
+	
+	prop = RNA_def_property(srna, "lift", PROP_FLOAT, PROP_COLOR_GAMMA);
+	RNA_def_property_float_sdna(prop, NULL, "lift");
+	RNA_def_property_array(prop, 3);
+	RNA_def_property_float_array_default(prop, default_col);
+	RNA_def_property_ui_range(prop, 0, 1, 0.1, 3);
+	RNA_def_property_ui_text(prop, "Lift", "Correction for Shadows");
+	RNA_def_property_update(prop, NC_NODE|NA_EDITED, "rna_Node_colorbalance_update");
+	
+	prop = RNA_def_property(srna, "gamma", PROP_FLOAT, PROP_COLOR_GAMMA);
+	RNA_def_property_float_sdna(prop, NULL, "gamma");
+	RNA_def_property_array(prop, 3);
+	RNA_def_property_float_array_default(prop, default_col);
+	RNA_def_property_ui_range(prop, 0, 1, 0.1, 3);
+	RNA_def_property_ui_text(prop, "Gamma", "Correction for Midtones");
+	RNA_def_property_update(prop, NC_NODE|NA_EDITED, "rna_Node_colorbalance_update");
+	
+	prop = RNA_def_property(srna, "gain", PROP_FLOAT, PROP_COLOR_GAMMA);
+	RNA_def_property_float_sdna(prop, NULL, "gain");
+	RNA_def_property_array(prop, 3);
+	RNA_def_property_float_array_default(prop, default_col);
+	RNA_def_property_ui_range(prop, 0, 1, 0.1, 3);
+	RNA_def_property_ui_text(prop, "Gain", "Correction for Highlights");
+	RNA_def_property_update(prop, NC_NODE|NA_EDITED, "rna_Node_colorbalance_update");
+}
 	
 
 
diff --git a/source/blender/makesrna/intern/rna_nodetree_types.h b/source/blender/makesrna/intern/rna_nodetree_types.h
index d9a1db996de..936832221f9 100644
--- a/source/blender/makesrna/intern/rna_nodetree_types.h
+++ b/source/blender/makesrna/intern/rna_nodetree_types.h
@@ -107,6 +107,7 @@ DefNode( CompositorNode, CMP_NODE_LENSDIST,       def_cmp_lensdist,       "LENSD
 DefNode( CompositorNode, CMP_NODE_VIEW_LEVELS,    def_cmp_levels,         "LEVELS",         Levels,           "Levels",            ""              )
 DefNode( CompositorNode, CMP_NODE_COLOR_MATTE,    def_cmp_color_matte,    "COLOR_MATTE",    ColorMatte,       "Color Matte",       ""              )
 DefNode( CompositorNode, CMP_NODE_DIST_MATTE,     def_cmp_distance_matte, "DISTANCE_MATTE", DistanceMatte,    "Distance Matte",    ""              )
+DefNode( CompositorNode, CMP_NODE_COLORBALANCE,   def_cmp_colorbalance,   "COLORBALANCE",   ColorBalance,     "Color Balance",     ""              )
                                                                                                                                                    
 DefNode( TextureNode,    TEX_NODE_OUTPUT,         def_tex_output,         "OUTPUT",         Output,           "Output",            ""              )
 DefNode( TextureNode,    TEX_NODE_CHECKER,        0,                      "CHECKER",        Checker,          "Checker",           ""              )