RendererServices API for letting get_texture_handle consider colorspa…

…ce (#1641)

This makes some minor changes to the RS APIs to add an additional
optional parameter to get_texture_handle so it takes a `TextureOpt*`
to accommodate a similar change on the OIIO TextureSystem side
from AcademySoftwareFoundation/OpenImageIO#3761

The purpose here is to add color management options to texture calls.
However, please note that this PR only reserves a public API change we
know we'll want, but it does not fully implement the color management.
Further work will be needed, as follows:

* Current calls to RS::get_texture_handle should be updated to pass
  the TextureOpt*. (This is a formality for future-proofing in case
  future TS or alternate TS implementations want to bake the color
  space choice into the texture handle itself. But the OIIO change
  doesn't currently rely on that at the moment.)

* When the texture.h symbol `OIIO_TEXTURESYSTEM_SUPPORTS_COLORSPACE`
  exists, we are building against an OIIO that has the new int field
  `colortransformid` in the TextureOpt and TextureOptBatch structures.
  We should fill this in with a nonzero value when we want the texture
  call to be doing a color transformation as it reads texture tiles.

* Use the new TextureSystem:get_colortransform_id() to get that color
  transform ID given two named from/to color spaces. We agreed that
  it's a reasonable restriction that the color space names should be
  known by the end of runtime optimization, so that should be constant
  foldable.

* Recognize new optional argument(s) to the texture() call family that
  lets the caller specify the presumed color space of the texture,
  and use that value (with constant folded lookup of the ID, above)
  to set the value in the TextureOpt.

Signed-off-by: Larry Gritz <lg@larrygritz.com>

CMakeLists.txt

@@ -4,7 +4,7 @@
 
 cmake_minimum_required (VERSION 3.12)
 
-set (OSL_VERSION "1.13.2.1")
+set (OSL_VERSION "1.13.3.0")
 set (OSL_VERSION_OVERRIDE "" CACHE STRING
      "Version override (use with caution)!")
 mark_as_advanced (OSL_VERSION_OVERRIDE)

src/include/OSL/rendererservices.h

@@ -186,10 +186,13 @@ class OSLEXECPUBLIC RendererServices {
     virtual bool get_userdata(bool derivatives, ustringhash name, TypeDesc type,
                               ShaderGlobals* sg, void* val);
 
-    /// Given the name of a texture, return an opaque handle that can be
-    /// used with texture calls to avoid the name lookups.
-    virtual TextureHandle* get_texture_handle(ustringhash filename,
-                                              ShadingContext* context);
+    /// Given the name of a texture, return an opaque handle that can be used
+    /// with texture calls to avoid the name lookups. The `options`, if not
+    /// null, may be used in renderer-specific ways to specialize a handle
+    /// based on certain texture option choices.
+    virtual TextureHandle*
+    get_texture_handle(ustringhash filename, ShadingContext* context,
+                       const TextureOpt* options = nullptr);
 
     /// Return true if the texture handle (previously returned by
     /// get_texture_handle()) is a valid texture that can be subsequently

src/liboslexec/llvm_gen.cpp

@@ -2461,7 +2461,9 @@ LLVMGEN(llvm_gen_texture)
     if (Filename.is_constant() && rop.shadingsys().opt_texture_handle()) {
         texture_handle
             = rop.renderer()->get_texture_handle(Filename.get_string(),
-                                                 rop.shadingcontext());
+                                                 rop.shadingcontext(), nullptr);
+        // FIXME(colorspace): that nullptr should be replaced by a TextureOpt*
+        // that has the colorspace set.
     }
 
     // Now call the osl_texture function, passing the options and all the
@@ -2526,7 +2528,9 @@ LLVMGEN(llvm_gen_texture3d)
     if (Filename.is_constant() && rop.shadingsys().opt_texture_handle()) {
         texture_handle
             = rop.renderer()->get_texture_handle(Filename.get_string(),
-                                                 rop.shadingcontext());
+                                                 rop.shadingcontext(), nullptr);
+        // FIXME(colorspace): that nullptr should be replaced by a TextureOpt*
+        // that has the colorspace set.
     }
 
     // Now call the osl_texture3d function, passing the options and all the
@@ -2589,7 +2593,9 @@ LLVMGEN(llvm_gen_environment)
     if (Filename.is_constant() && rop.shadingsys().opt_texture_handle()) {
         texture_handle
             = rop.renderer()->get_texture_handle(Filename.get_string(),
-                                                 rop.shadingcontext());
+                                                 rop.shadingcontext(), nullptr);
+        // FIXME(colorspace): that nullptr should be replaced by a TextureOpt*
+        // that has the colorspace set.
     }
 
     // Now call the osl_environment function, passing the options and all the
@@ -3040,7 +3046,7 @@ LLVMGEN(llvm_gen_gettextureinfo)
     if (Filename.is_constant() && rop.shadingsys().opt_texture_handle()) {
         texture_handle
             = rop.renderer()->get_texture_handle(Filename.get_string(),
-                                                 rop.shadingcontext());
+                                                 rop.shadingcontext(), nullptr);
     }
 
     std::vector<llvm::Value*> args;

src/liboslexec/rendservices.cpp

@@ -158,10 +158,17 @@ RendererServices::get_userdata(bool derivatives, ustringhash name,
 
 RendererServices::TextureHandle*
 RendererServices::get_texture_handle(ustringhash filename,
-                                     ShadingContext* context)
+                                     ShadingContext* context,
+                                     const TextureOpt* options)
 {
+#ifdef OIIO_TEXTURESYSTEM_SUPPORTS_COLORSPACE
+    return texturesys()->get_texture_handle(ustring_from(filename),
+                                            context->texture_thread_info(),
+                                            options);
+#else
     return texturesys()->get_texture_handle(ustring_from(filename),
                                             context->texture_thread_info());
+#endif
 }
 
 
@@ -194,8 +201,14 @@ RendererServices::texture(ustringhash filename, TextureHandle* texture_handle,
     if (!texture_thread_info)
         texture_thread_info = context->texture_thread_info();
     if (!texture_handle)
+#ifdef OIIO_TEXTURESYSTEM_SUPPORTS_COLORSPACE
+        texture_handle
+            = texturesys()->get_texture_handle(ustring_from(filename),
+                                               texture_thread_info, &options);
+#else
         texture_handle = texturesys()->get_texture_handle(ustring_from(filename),
                                                           texture_thread_info);
+#endif
     bool status = texturesys()->texture(texture_handle, texture_thread_info,
                                         options, s, t, dsdx, dtdx, dsdy, dtdy,
                                         nchannels, result, dresultds,
@@ -230,8 +243,14 @@ RendererServices::texture3d(ustringhash filename, TextureHandle* texture_handle,
     if (!texture_thread_info)
         texture_thread_info = context->texture_thread_info();
     if (!texture_handle)
+#ifdef OIIO_TEXTURESYSTEM_SUPPORTS_COLORSPACE
+        texture_handle
+            = texturesys()->get_texture_handle(ustring_from(filename),
+                                               texture_thread_info, &options);
+#else
         texture_handle = texturesys()->get_texture_handle(ustring_from(filename),
                                                           texture_thread_info);
+#endif
 
     bool status = texturesys()->texture3d(texture_handle, texture_thread_info,
                                           options, P, dPdx, dPdy, dPdz,
@@ -267,8 +286,14 @@ RendererServices::environment(ustringhash filename,
     if (!texture_thread_info)
         texture_thread_info = context->texture_thread_info();
     if (!texture_handle)
+#ifdef OIIO_TEXTURESYSTEM_SUPPORTS_COLORSPACE
+        texture_handle
+            = texturesys()->get_texture_handle(ustring_from(filename),
+                                               texture_thread_info, &options);
+#else
         texture_handle = texturesys()->get_texture_handle(ustring_from(filename),
                                                           texture_thread_info);
+#endif
     bool status = texturesys()->environment(texture_handle, texture_thread_info,
                                             options, R, dRdx, dRdy, nchannels,
                                             result, dresultds, dresultdt);

src/testrender/optixraytracer.cpp

@@ -883,7 +883,8 @@ OptixRaytracer::good(TextureHandle* handle OSL_MAYBE_UNUSED)
 /// used with texture calls to avoid the name lookups.
 RendererServices::TextureHandle*
 OptixRaytracer::get_texture_handle(ustringhash filename,
-                                   ShadingContext* /*shading_context*/)
+                                   ShadingContext* /*shading_context*/,
+                                   const TextureOpt* options)
 {
     auto itr = m_samplers.find(filename);
     if (itr == m_samplers.end()) {

src/testrender/optixraytracer.h

@@ -55,7 +55,8 @@ class OptixRaytracer final : public SimpleRaytracer {
     /// Given the name of a texture, return an opaque handle that can be
     /// used with texture calls to avoid the name lookups.
     TextureHandle* get_texture_handle(ustringhash filename,
-                                      ShadingContext* shading_context) override;
+                                      ShadingContext* shading_context,
+                                      const TextureOpt* options) override;
 
     // Easy way to do Optix calls
     optix::Context& optix_ctx() { return m_optix_ctx; }

src/testshade/optixgridrender.cpp

@@ -685,7 +685,8 @@ OptixGridRenderer::good(TextureHandle* handle OSL_MAYBE_UNUSED)
 /// used with texture calls to avoid the name lookups.
 RendererServices::TextureHandle*
 OptixGridRenderer::get_texture_handle(ustringhash filename,
-                                      ShadingContext* /*shading_context*/)
+                                      ShadingContext* /*shading_context*/,
+                                      const TextureOpt* /*options*/)
 {
     auto itr = m_samplers.find(filename);
     if (itr == m_samplers.end()) {

src/testshade/optixgridrender.h

@@ -61,7 +61,8 @@ class OptixGridRenderer final : public SimpleRenderer {
     /// Given the name of a texture, return an opaque handle that can be
     /// used with texture calls to avoid the name lookups.
     TextureHandle* get_texture_handle(ustringhash filename,
-                                      ShadingContext* shading_context) override;
+                                      ShadingContext* shading_context,
+                                      const TextureOpt* options) override;
 
     OptixDeviceContext optix_ctx() { return m_optix_ctx; }
     OptixDeviceContext context() { return m_optix_ctx; }

testsuite/example-cuda/cuda_grid_renderer.cpp

@@ -66,7 +66,8 @@ CudaGridRenderer::good(TextureHandle* handle)
 /// used with texture calls to avoid the name lookups.
 RendererServices::TextureHandle*
 CudaGridRenderer::get_texture_handle(OSL::ustringhash filename,
-                                     ShadingContext* shading_context)
+                                     ShadingContext* shading_context,
+                                     const TextureOpt* options)
 {
     auto itr = _samplers.find(filename);
     if (itr == _samplers.end()) {

testsuite/example-cuda/cuda_grid_renderer.h

@@ -57,7 +57,8 @@ class CudaGridRenderer final : public OSL::RendererServices {
     /// Given the name of a texture, return an opaque handle that can be
     /// used with texture calls to avoid the name lookups.
     virtual TextureHandle* get_texture_handle(ustringhash filename,
-                                              ShadingContext* shading_context);
+                                              ShadingContext* shading_context,
+                                              const TextureOpt* options);
 
     virtual bool get_matrix(ShaderGlobals* sg, Matrix44& result,
                             TransformationPtr xform, float time);