Cleanup: clarify what is scene linear color space in conversion conversion

* Rename ambiguous rgb to scene_linear in some places
* Precompute matrices to directly go to scene instead of through XYZ
* Make function signatures more consistent

5 files changed, 18 insertions, 14 deletions

diff --git a/intern/opencolorio/fallback_impl.cc b/intern/opencolorio/fallback_impl.cc
index 71b5ab9def2..8fc0ccd7918 100644
--- a/intern/opencolorio/fallback_impl.cc
+++ b/intern/opencolorio/fallback_impl.cc
@@ -241,10 +241,11 @@ void FallbackImpl::configGetDefaultLumaCoefs(OCIO_ConstConfigRcPtr * /*config*/,
   rgb[2] = 0.0722f;
 }
 
-void FallbackImpl::configGetXYZtoRGB(OCIO_ConstConfigRcPtr * /*config*/, float xyz_to_rgb[3][3])
+void FallbackImpl::configGetXYZtoSceneLinear(OCIO_ConstConfigRcPtr * /*config*/,
+                                             float xyz_to_scene_linear[3][3])
 {
   /* Default to ITU-BT.709. */
-  memcpy(xyz_to_rgb, OCIO_XYZ_TO_REC709, sizeof(OCIO_XYZ_TO_REC709));
+  memcpy(xyz_to_scene_linear, OCIO_XYZ_TO_REC709, sizeof(OCIO_XYZ_TO_REC709));
 }
 
 int FallbackImpl::configGetNumLooks(OCIO_ConstConfigRcPtr * /*config*/)
diff --git a/intern/opencolorio/ocio_capi.cc b/intern/opencolorio/ocio_capi.cc
index 5e4c2a87a0b..b31f3794361 100644
--- a/intern/opencolorio/ocio_capi.cc
+++ b/intern/opencolorio/ocio_capi.cc
@@ -118,9 +118,9 @@ void OCIO_configGetDefaultLumaCoefs(OCIO_ConstConfigRcPtr *config, float *rgb)
   impl->configGetDefaultLumaCoefs(config, rgb);
 }
 
-void OCIO_configGetXYZtoRGB(OCIO_ConstConfigRcPtr *config, float xyz_to_rgb[3][3])
+void OCIO_configGetXYZtoSceneLinear(OCIO_ConstConfigRcPtr *config, float xyz_to_scene_linear[3][3])
 {
-  impl->configGetXYZtoRGB(config, xyz_to_rgb);
+  impl->configGetXYZtoSceneLinear(config, xyz_to_scene_linear);
 }
 
 int OCIO_configGetNumLooks(OCIO_ConstConfigRcPtr *config)
diff --git a/intern/opencolorio/ocio_capi.h b/intern/opencolorio/ocio_capi.h
index 4be838a218d..97e6ff02779 100644
--- a/intern/opencolorio/ocio_capi.h
+++ b/intern/opencolorio/ocio_capi.h
@@ -135,7 +135,8 @@ const char *OCIO_configGetDisplayColorSpaceName(OCIO_ConstConfigRcPtr *config,
                                                 const char *view);
 
 void OCIO_configGetDefaultLumaCoefs(OCIO_ConstConfigRcPtr *config, float *rgb);
-void OCIO_configGetXYZtoRGB(OCIO_ConstConfigRcPtr *config, float xyz_to_rgb[3][3]);
+void OCIO_configGetXYZtoSceneLinear(OCIO_ConstConfigRcPtr *config,
+                                    float xyz_to_scene_linear[3][3]);
 
 int OCIO_configGetNumLooks(OCIO_ConstConfigRcPtr *config);
 const char *OCIO_configGetLookNameByIndex(OCIO_ConstConfigRcPtr *config, int index);
diff --git a/intern/opencolorio/ocio_impl.cc b/intern/opencolorio/ocio_impl.cc
index a352c54da86..7cf7fbefcd6 100644
--- a/intern/opencolorio/ocio_impl.cc
+++ b/intern/opencolorio/ocio_impl.cc
@@ -311,13 +311,14 @@ static bool to_scene_linear_matrix(ConstConfigRcPtr &config,
   return true;
 }
 
-void OCIOImpl::configGetXYZtoRGB(OCIO_ConstConfigRcPtr *config_, float xyz_to_rgb[3][3])
+void OCIOImpl::configGetXYZtoSceneLinear(OCIO_ConstConfigRcPtr *config_,
+                                         float xyz_to_scene_linear[3][3])
 {
   ConstConfigRcPtr config = (*(ConstConfigRcPtr *)config_);
 
   /* Default to ITU-BT.709 in case no appropriate transform found.
    * Note XYZ is defined here as having a D65 white point. */
-  memcpy(xyz_to_rgb, OCIO_XYZ_TO_REC709, sizeof(OCIO_XYZ_TO_REC709));
+  memcpy(xyz_to_scene_linear, OCIO_XYZ_TO_REC709, sizeof(OCIO_XYZ_TO_REC709));
 
   /* Get from OpenColorO config if it has the required roles. */
   if (!config->hasRole(ROLE_SCENE_LINEAR)) {
@@ -326,17 +327,17 @@ void OCIOImpl::configGetXYZtoRGB(OCIO_ConstConfigRcPtr *config_, float xyz_to_rg
 
   if (config->hasRole("aces_interchange")) {
     /* Standard OpenColorIO role, defined as ACES AP0 (ACES2065-1). */
-    float aces_to_rgb[3][3];
-    if (to_scene_linear_matrix(config, "aces_interchange", aces_to_rgb)) {
+    float aces_to_scene_linear[3][3];
+    if (to_scene_linear_matrix(config, "aces_interchange", aces_to_scene_linear)) {
       float xyz_to_aces[3][3];
       invert_m3_m3(xyz_to_aces, OCIO_ACES_TO_XYZ);
 
-      mul_m3_m3m3(xyz_to_rgb, aces_to_rgb, xyz_to_aces);
+      mul_m3_m3m3(xyz_to_scene_linear, aces_to_scene_linear, xyz_to_aces);
     }
   }
   else if (config->hasRole("XYZ")) {
     /* Custom role used before the standard existed. */
-    to_scene_linear_matrix(config, "XYZ", xyz_to_rgb);
+    to_scene_linear_matrix(config, "XYZ", xyz_to_scene_linear);
   }
 }
 
diff --git a/intern/opencolorio/ocio_impl.h b/intern/opencolorio/ocio_impl.h
index f8397c62e52..2c00eff6d6c 100644
--- a/intern/opencolorio/ocio_impl.h
+++ b/intern/opencolorio/ocio_impl.h
@@ -48,7 +48,8 @@ class IOCIOImpl {
                                                      const char *view) = 0;
 
   virtual void configGetDefaultLumaCoefs(OCIO_ConstConfigRcPtr *config, float *rgb) = 0;
-  virtual void configGetXYZtoRGB(OCIO_ConstConfigRcPtr *config, float xyz_to_rgb[3][3]) = 0;
+  virtual void configGetXYZtoSceneLinear(OCIO_ConstConfigRcPtr *config,
+                                         float xyz_to_scene_linear[3][3]) = 0;
 
   virtual int configGetNumLooks(OCIO_ConstConfigRcPtr *config) = 0;
   virtual const char *configGetLookNameByIndex(OCIO_ConstConfigRcPtr *config, int index) = 0;
@@ -167,7 +168,7 @@ class FallbackImpl : public IOCIOImpl {
                                              const char *view);
 
   void configGetDefaultLumaCoefs(OCIO_ConstConfigRcPtr *config, float *rgb);
-  void configGetXYZtoRGB(OCIO_ConstConfigRcPtr *config, float xyz_to_rgb[3][3]);
+  void configGetXYZtoSceneLinear(OCIO_ConstConfigRcPtr *config, float xyz_to_scene_linear[3][3]);
 
   int configGetNumLooks(OCIO_ConstConfigRcPtr *config);
   const char *configGetLookNameByIndex(OCIO_ConstConfigRcPtr *config, int index);
@@ -257,7 +258,7 @@ class OCIOImpl : public IOCIOImpl {
                                              const char *view);
 
   void configGetDefaultLumaCoefs(OCIO_ConstConfigRcPtr *config, float *rgb);
-  void configGetXYZtoRGB(OCIO_ConstConfigRcPtr *config, float xyz_to_rgb[3][3]);
+  void configGetXYZtoSceneLinear(OCIO_ConstConfigRcPtr *config, float xyz_to_scene_linear[3][3]);
 
   int configGetNumLooks(OCIO_ConstConfigRcPtr *config);
   const char *configGetLookNameByIndex(OCIO_ConstConfigRcPtr *config, int index);