Cycles: support loading images from arbitrary OpenColorIO color space

These are the internal changes to Cycles, for Blender integration there are no
functional changes in this commit.

Images are converted to scene linear color space on file load, and on reading
from the OpenImageIO texture cache. 8-bit images are compressed with the sRGB
transfer function to avoid precision loss while keeping memory usages low. This
also means that for common cases of 8-bit sRGB images no conversion happens at
all on image loading.

Initial patch by Lukas, completed by Brecht.

Differential Revision: https://developer.blender.org/D3491

1 files changed, 4 insertions, 9 deletions

diff --git a/intern/cycles/kernel/osl/osl_globals.h b/intern/cycles/kernel/osl/osl_globals.h
index 414aaf891db..51bc5cf81a9 100644
--- a/intern/cycles/kernel/osl/osl_globals.h
+++ b/intern/cycles/kernel/osl/osl_globals.h
@@ -37,6 +37,7 @@ using std::isfinite;
 CCL_NAMESPACE_BEGIN
 
 class OSLRenderServices;
+class ColorSpaceProcessor;
 
 /* OSL Texture Handle
  *
@@ -53,21 +54,15 @@ class OSLRenderServices;
 struct OSLTextureHandle : public OIIO::RefCnt {
   enum Type { OIIO, SVM, IES, BEVEL, AO };
 
-  OSLTextureHandle() : type(OIIO), svm_slot(-1), oiio_handle(NULL)
-  {
-  }
-
-  OSLTextureHandle(Type type) : type(type), svm_slot(-1), oiio_handle(NULL)
-  {
-  }
-
-  OSLTextureHandle(Type type, int svm_slot) : type(type), svm_slot(svm_slot), oiio_handle(NULL)
+  OSLTextureHandle(Type type = OIIO, int svm_slot = -1)
+      : type(type), svm_slot(svm_slot), oiio_handle(NULL), processor(NULL)
   {
   }
 
   Type type;
   int svm_slot;
   OSL::TextureSystem::TextureHandle *oiio_handle;
+  ColorSpaceProcessor *processor;
 };
 
 typedef OIIO::intrusive_ptr<OSLTextureHandle> OSLTextureHandleRef;