OpenColorIO: upgrade to version 2.0.0

Ref T84819

Build System
============

This is an API breaking new version, and the updated code only builds with
OpenColorIO 2.0 and later. Adding backwards compatibility was too complicated.

* Tinyxml was replaced with Expat, adding a new dependency.
* Yaml-cpp is now built as a dependency on Unix, as was already done on Windows.
* Removed currently unused LCMS code.
* Pystring remains built as part of OCIO itself, since it has no good build system.
* Linux and macOS check for the OpenColorIO verison, and disable it if too old.

Ref D10270

Processors and Transforms
=========================

CPU processors now need to be created to do CPU processing. These are cached
internally, but the cache lookup is not fast enough to execute per pixel or
texture sample, so for performance these are now also exposed in the C API.

The C API for transforms will no longer be needed afer all changes, so remove
it to simplify the API and fallback implementation.

Ref D10271

Display Transforms
==================

Needs a bit more manual work constructing the transform. LegacyViewingPipeline
could also have been used, but isn't really any simpler and since it's legacy
we better not rely on it.

We moved more logic into the opencolorio module, to simplify the API. There is
no need to wrap a dozen functions just to be able to do this in C rather than C++.
It's also tightly coupled to the GPU shader logic, and so should be in the same
module.

Ref D10271

GPU Display Shader
==================

To avoid baking exposure and gamma into the GLSL shader and requiring slow
recompiles when tweaking, we manually apply them in the shader. This leads
to some logic duplicaton between the CPU and GPU display processor, but it
seems unavoidable.

Caching was also changed. Previously this was done both on the imbuf and
opencolorio module levels. Now it's all done in the opencolorio module by
simply matching color space names. We no longer use cacheIDs from OpenColorIO
since computing them is expensive, and they are unlikely to match now that
more is baked into the shader code.

Shaders can now use multiple 2D textures, 3D textures and uniforms, rather
than a single 3D texture. So allocating and binding those adds some code.

Color space conversions for blending with overlays is now hardcoded in the
shader. This was using harcoded numbers anyway, if this every becomes a
general OpenColorIO transform it can be changed, but for now there is no
point to add code complexity.

Ref D10273

CIE XYZ
=======

We need standard CIE XYZ values for rendering effects like blackbody emission.
The relation to the scene linear role is based on OpenColorIO configuration.

In OpenColorIO 2.0 configs roles can no longer have the same name as color
spaces, which means our XYZ role and colorspace in the configuration give an
error.

Instead use the new standard aces_interchange role, which relates scene linear
to a known scene referred color space. Compatibility with the old XYZ role is
preserved, if the configuration file has no conflicting names.

Also includes a non-functional change to the configuraton file to use an
XYZ-to-ACES matrix instead of REC709-to-ACES, makes debugging a little easier
since the matrix is the same one we have in the code now and that is also
found easily in the ACES specs.

Ref D10274

1 files changed, 71 insertions, 295 deletions

diff --git a/intern/opencolorio/fallback_impl.cc b/intern/opencolorio/fallback_impl.cc
index a6b93ac4959..9bbc9843e9d 100644
--- a/intern/opencolorio/fallback_impl.cc
+++ b/intern/opencolorio/fallback_impl.cc
@@ -34,7 +34,7 @@ using std::max;
 enum TransformType {
   TRANSFORM_LINEAR_TO_SRGB,
   TRANSFORM_SRGB_TO_LINEAR,
-  TRANSFORM_MATRIX,
+  TRANSFORM_SCALE,
   TRANSFORM_EXPONENT,
   TRANSFORM_UNKNOWN,
 };
@@ -53,147 +53,72 @@ typedef struct OCIO_PackedImageDescription {
 } OCIO_PackedImageDescription;
 
 struct FallbackTransform {
-  FallbackTransform() : type(TRANSFORM_UNKNOWN), linear_transform(NULL), display_transform(NULL)
+  FallbackTransform() : type(TRANSFORM_UNKNOWN), scale(1.0f), exponent(1.0f)
   {
   }
 
   virtual ~FallbackTransform()
   {
-    delete linear_transform;
-    delete display_transform;
   }
 
   void applyRGB(float *pixel)
   {
     if (type == TRANSFORM_LINEAR_TO_SRGB) {
-      applyLinearRGB(pixel);
+      pixel[0] *= scale;
+      pixel[1] *= scale;
+      pixel[2] *= scale;
+
       linearrgb_to_srgb_v3_v3(pixel, pixel);
-      applyDisplayRGB(pixel);
+
+      pixel[0] = powf(max(0.0f, pixel[0]), exponent);
+      pixel[1] = powf(max(0.0f, pixel[1]), exponent);
+      pixel[2] = powf(max(0.0f, pixel[2]), exponent);
     }
     else if (type == TRANSFORM_SRGB_TO_LINEAR) {
       srgb_to_linearrgb_v3_v3(pixel, pixel);
     }
     else if (type == TRANSFORM_EXPONENT) {
-      pixel[0] = powf(max(0.0f, pixel[0]), exponent[0]);
-      pixel[1] = powf(max(0.0f, pixel[1]), exponent[1]);
-      pixel[2] = powf(max(0.0f, pixel[2]), exponent[2]);
+      pixel[0] = powf(max(0.0f, pixel[0]), exponent);
+      pixel[1] = powf(max(0.0f, pixel[1]), exponent);
+      pixel[2] = powf(max(0.0f, pixel[2]), exponent);
     }
-    else if (type == TRANSFORM_MATRIX) {
-      float r = pixel[0];
-      float g = pixel[1];
-      float b = pixel[2];
-      pixel[0] = r * matrix[0] + g * matrix[1] + b * matrix[2];
-      pixel[1] = r * matrix[4] + g * matrix[5] + b * matrix[6];
-      pixel[2] = r * matrix[8] + g * matrix[9] + b * matrix[10];
-      pixel[0] += offset[0];
-      pixel[1] += offset[1];
-      pixel[2] += offset[2];
+    else if (type == TRANSFORM_SCALE) {
+      pixel[0] *= scale;
+      pixel[1] *= scale;
+      pixel[2] *= scale;
     }
   }
 
   void applyRGBA(float *pixel)
   {
-    if (type == TRANSFORM_LINEAR_TO_SRGB) {
-      applyLinearRGBA(pixel);
-      linearrgb_to_srgb_v4(pixel, pixel);
-      applyDisplayRGBA(pixel);
-    }
-    else if (type == TRANSFORM_SRGB_TO_LINEAR) {
-      srgb_to_linearrgb_v4(pixel, pixel);
-    }
-    else if (type == TRANSFORM_EXPONENT) {
-      pixel[0] = powf(max(0.0f, pixel[0]), exponent[0]);
-      pixel[1] = powf(max(0.0f, pixel[1]), exponent[1]);
-      pixel[2] = powf(max(0.0f, pixel[2]), exponent[2]);
-      pixel[3] = powf(max(0.0f, pixel[3]), exponent[3]);
-    }
-    else if (type == TRANSFORM_MATRIX) {
-      float r = pixel[0];
-      float g = pixel[1];
-      float b = pixel[2];
-      float a = pixel[3];
-      pixel[0] = r * matrix[0] + g * matrix[1] + b * matrix[2] + a * matrix[3];
-      pixel[1] = r * matrix[4] + g * matrix[5] + b * matrix[6] + a * matrix[7];
-      pixel[2] = r * matrix[8] + g * matrix[9] + b * matrix[10] + a * matrix[11];
-      pixel[3] = r * matrix[12] + g * matrix[13] + b * matrix[14] + a * matrix[15];
-      pixel[0] += offset[0];
-      pixel[1] += offset[1];
-      pixel[2] += offset[2];
-      pixel[3] += offset[3];
-    }
-  }
-
-  void applyLinearRGB(float *pixel)
-  {
-    if (linear_transform != NULL) {
-      linear_transform->applyRGB(pixel);
-    }
-  }
-
-  void applyLinearRGBA(float *pixel)
-  {
-    if (linear_transform != NULL) {
-      linear_transform->applyRGBA(pixel);
-    }
-  }
-
-  void applyDisplayRGB(float *pixel)
-  {
-    if (display_transform != NULL) {
-      display_transform->applyRGB(pixel);
-    }
-  }
-
-  void applyDisplayRGBA(float *pixel)
-  {
-    if (display_transform != NULL) {
-      display_transform->applyRGBA(pixel);
-    }
+    applyRGB(pixel);
   }
 
   TransformType type;
-  FallbackTransform *linear_transform;
-  FallbackTransform *display_transform;
+  /* Scale transform. */
+  float scale;
   /* Exponent transform. */
-  float exponent[4];
-  /* Matrix transform. */
-  float matrix[16];
-  float offset[4];
+  float exponent;
 
   MEM_CXX_CLASS_ALLOC_FUNCS("FallbackTransform");
 };
 
-struct FallbackGroupTransform : FallbackTransform {
-  ~FallbackGroupTransform()
-  {
-    for (auto transform : list) {
-      delete transform;
-    }
-  }
-  std::vector<FallbackTransform *> list;
-};
-
 struct FallbackProcessor {
-  FallbackProcessor() : transform(NULL)
+  FallbackProcessor(const FallbackTransform &transform) : transform(transform)
   {
   }
 
-  ~FallbackProcessor()
-  {
-    delete transform;
-  }
-
   void applyRGB(float *pixel)
   {
-    transform->applyRGB(pixel);
+    transform.applyRGB(pixel);
   }
 
   void applyRGBA(float *pixel)
   {
-    transform->applyRGBA(pixel);
+    transform.applyRGBA(pixel);
   }
 
-  FallbackTransform *transform;
+  FallbackTransform transform;
 
   MEM_CXX_CLASS_ALLOC_FUNCS("FallbackProcessor");
 };
@@ -403,30 +328,35 @@ OCIO_ConstProcessorRcPtr *FallbackImpl::configGetProcessorWithNames(OCIO_ConstCo
 {
   OCIO_ConstColorSpaceRcPtr *cs_src = configGetColorSpace(config, srcName);
   OCIO_ConstColorSpaceRcPtr *cs_dst = configGetColorSpace(config, dstName);
-  FallbackTransform *transform = new FallbackTransform();
+  FallbackTransform transform;
   if (cs_src == COLORSPACE_LINEAR && cs_dst == COLORSPACE_SRGB) {
-    transform->type = TRANSFORM_LINEAR_TO_SRGB;
+    transform.type = TRANSFORM_LINEAR_TO_SRGB;
   }
   else if (cs_src == COLORSPACE_SRGB && cs_dst == COLORSPACE_LINEAR) {
-    transform->type = TRANSFORM_SRGB_TO_LINEAR;
+    transform.type = TRANSFORM_SRGB_TO_LINEAR;
   }
   else {
-    transform->type = TRANSFORM_UNKNOWN;
+    transform.type = TRANSFORM_UNKNOWN;
   }
-  FallbackProcessor *processor = new FallbackProcessor();
-  processor->transform = transform;
-  return (OCIO_ConstProcessorRcPtr *)processor;
+  return (OCIO_ConstProcessorRcPtr *)new FallbackProcessor(transform);
+}
+
+OCIO_ConstCPUProcessorRcPtr *FallbackImpl::processorGetCPUProcessor(
+    OCIO_ConstProcessorRcPtr *processor)
+{
+  /* Just make a copy of the processor so that we are compatible with OCIO
+   * which does need it as a separate object. */
+  FallbackProcessor *fallback_processor = (FallbackProcessor *)processor;
+  return (OCIO_ConstCPUProcessorRcPtr *)new FallbackProcessor(*fallback_processor);
 }
 
-OCIO_ConstProcessorRcPtr *FallbackImpl::configGetProcessor(OCIO_ConstConfigRcPtr * /*config*/,
-                                                           OCIO_ConstTransformRcPtr *transform)
+void FallbackImpl::processorRelease(OCIO_ConstProcessorRcPtr *processor)
 {
-  FallbackProcessor *processor = new FallbackProcessor();
-  processor->transform = (FallbackTransform *)transform;
-  return (OCIO_ConstProcessorRcPtr *)processor;
+  delete (FallbackProcessor *)(processor);
 }
 
-void FallbackImpl::processorApply(OCIO_ConstProcessorRcPtr *processor, OCIO_PackedImageDesc *img)
+void FallbackImpl::cpuProcessorApply(OCIO_ConstCPUProcessorRcPtr *cpu_processor,
+                                     OCIO_PackedImageDesc *img)
 {
   /* OCIO_TODO stride not respected, channels must be 3 or 4 */
   OCIO_PackedImageDescription *desc = (OCIO_PackedImageDescription *)img;
@@ -441,15 +371,15 @@ void FallbackImpl::processorApply(OCIO_ConstProcessorRcPtr *processor, OCIO_Pack
       float *pixel = pixels + channels * (y * width + x);
 
       if (channels == 4)
-        processorApplyRGBA(processor, pixel);
+        cpuProcessorApplyRGBA(cpu_processor, pixel);
       else if (channels == 3)
-        processorApplyRGB(processor, pixel);
+        cpuProcessorApplyRGB(cpu_processor, pixel);
     }
   }
 }
 
-void FallbackImpl::processorApply_predivide(OCIO_ConstProcessorRcPtr *processor,
-                                            OCIO_PackedImageDesc *img)
+void FallbackImpl::cpuProcessorApply_predivide(OCIO_ConstCPUProcessorRcPtr *cpu_processor,
+                                               OCIO_PackedImageDesc *img)
 {
   /* OCIO_TODO stride not respected, channels must be 3 or 4 */
   OCIO_PackedImageDescription *desc = (OCIO_PackedImageDescription *)img;
@@ -464,27 +394,28 @@ void FallbackImpl::processorApply_predivide(OCIO_ConstProcessorRcPtr *processor,
       float *pixel = pixels + channels * (y * width + x);
 
       if (channels == 4)
-        processorApplyRGBA_predivide(processor, pixel);
+        cpuProcessorApplyRGBA_predivide(cpu_processor, pixel);
       else if (channels == 3)
-        processorApplyRGB(processor, pixel);
+        cpuProcessorApplyRGB(cpu_processor, pixel);
     }
   }
 }
 
-void FallbackImpl::processorApplyRGB(OCIO_ConstProcessorRcPtr *processor, float *pixel)
+void FallbackImpl::cpuProcessorApplyRGB(OCIO_ConstCPUProcessorRcPtr *cpu_processor, float *pixel)
 {
-  ((FallbackProcessor *)processor)->applyRGB(pixel);
+  ((FallbackProcessor *)cpu_processor)->applyRGB(pixel);
 }
 
-void FallbackImpl::processorApplyRGBA(OCIO_ConstProcessorRcPtr *processor, float *pixel)
+void FallbackImpl::cpuProcessorApplyRGBA(OCIO_ConstCPUProcessorRcPtr *cpu_processor, float *pixel)
 {
-  ((FallbackProcessor *)processor)->applyRGBA(pixel);
+  ((FallbackProcessor *)cpu_processor)->applyRGBA(pixel);
 }
 
-void FallbackImpl::processorApplyRGBA_predivide(OCIO_ConstProcessorRcPtr *processor, float *pixel)
+void FallbackImpl::cpuProcessorApplyRGBA_predivide(OCIO_ConstCPUProcessorRcPtr *cpu_processor,
+                                                   float *pixel)
 {
   if (pixel[3] == 1.0f || pixel[3] == 0.0f) {
-    processorApplyRGBA(processor, pixel);
+    cpuProcessorApplyRGBA(cpu_processor, pixel);
   }
   else {
     float alpha, inv_alpha;
@@ -496,7 +427,7 @@ void FallbackImpl::processorApplyRGBA_predivide(OCIO_ConstProcessorRcPtr *proces
     pixel[1] *= inv_alpha;
     pixel[2] *= inv_alpha;
 
-    processorApplyRGBA(processor, pixel);
+    cpuProcessorApplyRGBA(cpu_processor, pixel);
 
     pixel[0] *= alpha;
     pixel[1] *= alpha;
@@ -504,9 +435,9 @@ void FallbackImpl::processorApplyRGBA_predivide(OCIO_ConstProcessorRcPtr *proces
   }
 }
 
-void FallbackImpl::processorRelease(OCIO_ConstProcessorRcPtr *processor)
+void FallbackImpl::cpuProcessorRelease(OCIO_ConstCPUProcessorRcPtr *cpu_processor)
 {
-  delete (FallbackProcessor *)(processor);
+  delete (FallbackProcessor *)(cpu_processor);
 }
 
 const char *FallbackImpl::colorSpaceGetName(OCIO_ConstColorSpaceRcPtr *cs)
@@ -530,54 +461,20 @@ const char *FallbackImpl::colorSpaceGetFamily(OCIO_ConstColorSpaceRcPtr * /*cs*/
   return "";
 }
 
-OCIO_DisplayTransformRcPtr *FallbackImpl::createDisplayTransform(void)
-{
-  FallbackTransform *transform = new FallbackTransform();
-  transform->type = TRANSFORM_LINEAR_TO_SRGB;
-  return (OCIO_DisplayTransformRcPtr *)transform;
-}
-
-void FallbackImpl::displayTransformSetInputColorSpaceName(OCIO_DisplayTransformRcPtr * /*dt*/,
-                                                          const char * /*name*/)
-{
-}
-
-void FallbackImpl::displayTransformSetDisplay(OCIO_DisplayTransformRcPtr * /*dt*/,
-                                              const char * /*name*/)
-{
-}
-
-void FallbackImpl::displayTransformSetView(OCIO_DisplayTransformRcPtr * /*dt*/,
-                                           const char * /*name*/)
-{
-}
-
-void FallbackImpl::displayTransformSetDisplayCC(OCIO_DisplayTransformRcPtr *dt,
-                                                OCIO_ConstTransformRcPtr *et)
-{
-  FallbackTransform *transform = (FallbackTransform *)dt;
-  transform->display_transform = (FallbackTransform *)et;
-}
-
-void FallbackImpl::displayTransformSetLinearCC(OCIO_DisplayTransformRcPtr *dt,
-                                               OCIO_ConstTransformRcPtr *et)
-{
-  FallbackTransform *transform = (FallbackTransform *)dt;
-  transform->linear_transform = (FallbackTransform *)et;
-}
-
-void FallbackImpl::displayTransformSetLooksOverride(OCIO_DisplayTransformRcPtr * /*dt*/,
-                                                    const char * /*looks*/)
-{
-}
-
-void FallbackImpl::displayTransformSetLooksOverrideEnabled(OCIO_DisplayTransformRcPtr * /*dt*/,
-                                                           bool /*enabled*/)
+OCIO_ConstProcessorRcPtr *FallbackImpl::createDisplayProcessor(OCIO_ConstConfigRcPtr * /*config*/,
+                                                               const char * /*input*/,
+                                                               const char * /*view*/,
+                                                               const char * /*display*/,
+                                                               const char * /*look*/,
+                                                               const float scale,
+                                                               const float exponent)
 {
-}
+  FallbackTransform transform;
+  transform.type = TRANSFORM_LINEAR_TO_SRGB;
+  transform.scale = scale;
+  transform.exponent = exponent;
 
-void FallbackImpl::displayTransformRelease(OCIO_DisplayTransformRcPtr * /*dt*/)
-{
+  return (OCIO_ConstProcessorRcPtr *)new FallbackProcessor(transform);
 }
 
 OCIO_PackedImageDesc *FallbackImpl::createOCIO_PackedImageDesc(float *data,
@@ -605,127 +502,6 @@ void FallbackImpl::OCIO_PackedImageDescRelease(OCIO_PackedImageDesc *id)
   MEM_freeN(id);
 }
 
-OCIO_GroupTransformRcPtr *FallbackImpl::createGroupTransform(void)
-{
-  FallbackTransform *transform = new FallbackGroupTransform();
-  transform->type = TRANSFORM_UNKNOWN;
-  return (OCIO_GroupTransformRcPtr *)transform;
-}
-
-void FallbackImpl::groupTransformSetDirection(OCIO_GroupTransformRcPtr * /*gt*/,
-                                              const bool /*forward */)
-{
-}
-
-void FallbackImpl::groupTransformPushBack(OCIO_GroupTransformRcPtr *gt,
-                                          OCIO_ConstTransformRcPtr *transform)
-{
-  FallbackGroupTransform *group = (FallbackGroupTransform *)gt;
-  group->list.push_back((FallbackTransform *)transform);
-}
-
-void FallbackImpl::groupTransformRelease(OCIO_GroupTransformRcPtr * /*gt*/)
-{
-}
-
-OCIO_ColorSpaceTransformRcPtr *FallbackImpl::createColorSpaceTransform(void)
-{
-  FallbackTransform *transform = new FallbackTransform();
-  transform->type = TRANSFORM_UNKNOWN;
-  return (OCIO_ColorSpaceTransformRcPtr *)transform;
-}
-
-void FallbackImpl::colorSpaceTransformSetSrc(OCIO_ColorSpaceTransformRcPtr * /*ct*/,
-                                             const char * /*name*/)
-{
-}
-
-void FallbackImpl::colorSpaceTransformRelease(OCIO_ColorSpaceTransformRcPtr * /*ct*/)
-{
-}
-
-OCIO_ExponentTransformRcPtr *FallbackImpl::createExponentTransform(void)
-{
-  FallbackTransform *transform = new FallbackTransform();
-  transform->type = TRANSFORM_EXPONENT;
-  return (OCIO_ExponentTransformRcPtr *)transform;
-}
-
-void FallbackImpl::exponentTransformSetValue(OCIO_ExponentTransformRcPtr *et,
-                                             const float *exponent)
-{
-  FallbackTransform *transform = (FallbackTransform *)et;
-  copy_v4_v4(transform->exponent, exponent);
-}
-
-void FallbackImpl::exponentTransformRelease(OCIO_ExponentTransformRcPtr * /*et*/)
-{
-}
-
-OCIO_MatrixTransformRcPtr *FallbackImpl::createMatrixTransform(void)
-{
-  FallbackTransform *transform = new FallbackTransform();
-  transform->type = TRANSFORM_MATRIX;
-  return (OCIO_MatrixTransformRcPtr *)transform;
-}
-
-void FallbackImpl::matrixTransformSetValue(OCIO_MatrixTransformRcPtr *mt,
-                                           const float *m44,
-                                           const float *offset4)
-{
-  FallbackTransform *transform = (FallbackTransform *)mt;
-  copy_m4_m4((float(*)[4])transform->matrix, (float(*)[4])m44);
-  copy_v4_v4(transform->offset, offset4);
-}
-
-void FallbackImpl::matrixTransformRelease(OCIO_MatrixTransformRcPtr * /*mt*/)
-{
-}
-
-void FallbackImpl::matrixTransformScale(float *m44, float *offset4, const float *scale4)
-{
-  if (scale4 == NULL) {
-    return;
-  }
-  if (m44 != NULL) {
-    memset(m44, 0, 16 * sizeof(float));
-    m44[0] = scale4[0];
-    m44[5] = scale4[1];
-    m44[10] = scale4[2];
-    m44[15] = scale4[3];
-  }
-  if (offset4 != NULL) {
-    offset4[0] = 0.0f;
-    offset4[1] = 0.0f;
-    offset4[2] = 0.0f;
-    offset4[3] = 0.0f;
-  }
-}
-
-bool FallbackImpl::supportGLSLDraw(void)
-{
-  return false;
-}
-
-bool FallbackImpl::setupGLSLDraw(struct OCIO_GLSLDrawState ** /*state_r*/,
-                                 OCIO_ConstProcessorRcPtr * /*ocio_processor_scene_to_ui*/,
-                                 OCIO_ConstProcessorRcPtr * /*ocio_processor_ui_to_display*/,
-                                 OCIO_CurveMappingSettings * /*curve_mapping_settings*/,
-                                 float /*dither*/,
-                                 bool /*predivide*/,
-                                 bool /*overlay*/)
-{
-  return false;
-}
-
-void FallbackImpl::finishGLSLDraw(OCIO_GLSLDrawState * /*state*/)
-{
-}
-
-void FallbackImpl::freeGLState(struct OCIO_GLSLDrawState * /*state_r*/)
-{
-}
-
 const char *FallbackImpl::getVersionString(void)
 {
   return "fallback";