OCIO LookTransform inversion

Patch

diff --git a/src/OpenColorIO/transforms/LookTransform.cpp b/src/OpenColorIO/transforms/LookTransform.cpp
index 5458e9a9..8afee104 100755
--- a/src/OpenColorIO/transforms/LookTransform.cpp
+++ b/src/OpenColorIO/transforms/LookTransform.cpp
@@ -327,12 +327,13 @@ void BuildLookOps(OpRcPtrVec & ops,
     looks.parse(lookTransform.getLooks());
 
     // We must handle the inverse src/dst colorspace transformation explicitly.
-    if(dir == TRANSFORM_DIR_INVERSE)
+    auto combinedDir = CombineTransformDirections(dir, lookTransform.getDirection());
+    if(combinedDir == TRANSFORM_DIR_INVERSE)
     {
         std::swap(src, dst);
         looks.reverse();
     }
-    else if(dir == TRANSFORM_DIR_UNKNOWN)
+    else if(combinedDir == TRANSFORM_DIR_UNKNOWN)
     {
         std::ostringstream os;
         os << "BuildLookOps error. A valid transform direction must be specified.";
@@ -430,7 +431,7 @@ void BuildLookOps(OpRcPtrVec & ops,
     }
 }
 
-bool CollectContextVariables(const Config & config, 
+bool CollectContextVariables(const Config & config,
                              const Context & context,
                              const LookTransform & look,
                              ContextRcPtr & usedContextVars)

UnitTest

diff --git a/tests/cpu/transforms/LookTransform_tests.cpp b/tests/cpu/transforms/LookTransform_tests.cpp
index 89c265e0..522891dd 100644
--- a/tests/cpu/transforms/LookTransform_tests.cpp
+++ b/tests/cpu/transforms/LookTransform_tests.cpp
@@ -2,7 +2,10 @@
 // Copyright Contributors to the OpenColorIO Project.
 
 
+#include "ops/cdl/CDLOpData.h"
 #include "ops/fixedfunction/FixedFunctionOpData.h"
+#include "ops/gamma/GammaOpData.h"
+#include "ops/log/LogOpData.h"
 
 #include "transforms/LookTransform.cpp"
 
@@ -559,3 +562,191 @@ colorspaces:
     OCIO_CHECK_EQUAL(std::string("FILE2"), usedContextVars->getStringVarNameByIndex(1));
     OCIO_CHECK_EQUAL(std::string("cdl_test1.cc"), usedContextVars->getStringVarByIndex(1));}
 
+
+OCIO_ADD_TEST(LookTransform, inline_look_transform)
+{
+    constexpr const char * OCIO_CONFIG{ R"(
+ocio_profile_version: 2
+
+search_path: luts
+
+roles:
+  default: raw
+
+displays:
+  sRGB:
+    - !<View> {name: Raw, colorspace: raw}
+
+looks:
+  - !<Look>
+    name: look1
+    process_space: log
+    transform: !<CDLTransform> {sat: 0.8}
+
+colorspaces:
+  - !<ColorSpace>
+    name: raw
+    family: raw
+    bitdepth: 32f
+    isdata: false
+
+  - !<ColorSpace>
+    name: log
+    to_reference: !<LogTransform> {base: 2, direction: inverse}
+
+  - !<ColorSpace>
+    name: vd
+    from_reference: !<ExponentTransform> {value: [2.4, 2.4, 2.4, 1], direction: inverse}
+
+  - !<ColorSpace>
+    name: vd_graded
+    from_reference: !<GroupTransform>
+      children:
+        - !<LookTransform> {src: raw, dst: vd, looks: look1}
+
+  - !<ColorSpace>
+    name: vd_graded_2
+    to_reference: !<GroupTransform>
+      children:
+        - !<LookTransform> {src: raw, dst: vd, looks: look1, direction: inverse}
+
+)" };
+
+    std::istringstream is;
+    is.str(OCIO_CONFIG);
+
+    OCIO::ConstConfigRcPtr config;
+    OCIO_CHECK_NO_THROW(config = OCIO::Config::CreateFromStream(is));
+    OCIO_CHECK_NO_THROW(config->validate());
+
+    OCIO::ConstColorSpaceRcPtr srcColorSpace;
+    OCIO_CHECK_NO_THROW(srcColorSpace = config->getColorSpace("raw"));
+    OCIO::ConstColorSpaceRcPtr dstColorSpace;
+    OCIO_CHECK_NO_THROW(dstColorSpace = config->getColorSpace("vd_graded"));
+
+    OCIO::OpRcPtrVec ops;
+    OCIO_CHECK_NO_THROW(BuildColorSpaceOps(ops, *config, config->getCurrentContext(),
+                                           srcColorSpace, dstColorSpace, false));
+    OCIO_CHECK_NO_THROW(ops.validate());
+    OCIO_REQUIRE_EQUAL(ops.size(), 11);
+    OCIO::ConstOpRcPtr op = ops[0];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[1];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[2]; // raw to log
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::LogType);
+    auto lg = OCIO_DYNAMIC_POINTER_CAST<const OCIO::LogOpData>(op->data());
+    OCIO_CHECK_ASSERT(lg);
+    OCIO_CHECK_EQUAL(lg->getDirection(), OCIO::TRANSFORM_DIR_FORWARD);
+    op = ops[3];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[4];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[5];  // look
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::CDLType);
+    auto cdl = OCIO_DYNAMIC_POINTER_CAST<const OCIO::CDLOpData>(op->data());
+    OCIO_CHECK_ASSERT(cdl);
+    OCIO_CHECK_EQUAL(cdl->getDirection(), OCIO::TRANSFORM_DIR_FORWARD);
+    op = ops[6];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[7]; // log to raw
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::LogType);
+    lg = OCIO_DYNAMIC_POINTER_CAST<const OCIO::LogOpData>(op->data());
+    OCIO_CHECK_ASSERT(lg);
+    OCIO_CHECK_EQUAL(lg->getDirection(), OCIO::TRANSFORM_DIR_INVERSE);
+    op = ops[8]; // raw to vd
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::GammaType);
+    auto gm = OCIO_DYNAMIC_POINTER_CAST<const OCIO::GammaOpData>(op->data());
+    OCIO_CHECK_ASSERT(gm);
+    OCIO_CHECK_EQUAL(gm->getDirection(), OCIO::TRANSFORM_DIR_INVERSE);
+    op = ops[9];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[10];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+
+    // Test in inverse direction.
+    ops.clear();
+    OCIO_CHECK_NO_THROW(BuildColorSpaceOps(ops, *config, config->getCurrentContext(),
+                                           dstColorSpace, srcColorSpace, false));
+    OCIO_REQUIRE_EQUAL(ops.size(), 11);
+    OCIO_CHECK_NO_THROW(ops.validate());
+    op = ops[0];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[1];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[2]; // vd to raw
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::GammaType);
+    gm = OCIO_DYNAMIC_POINTER_CAST<const OCIO::GammaOpData>(op->data());
+    OCIO_CHECK_ASSERT(gm);
+    OCIO_CHECK_EQUAL(gm->getDirection(), OCIO::TRANSFORM_DIR_FORWARD);
+    op = ops[3]; // raw to log
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::LogType);
+    lg = OCIO_DYNAMIC_POINTER_CAST<const OCIO::LogOpData>(op->data());
+    OCIO_CHECK_ASSERT(lg);
+    OCIO_CHECK_EQUAL(lg->getDirection(), OCIO::TRANSFORM_DIR_FORWARD);
+    op = ops[4];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[5];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[6]; // look
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::CDLType);
+    cdl = OCIO_DYNAMIC_POINTER_CAST<const OCIO::CDLOpData>(op->data());
+    OCIO_CHECK_ASSERT(cdl);
+    OCIO_CHECK_EQUAL(cdl->getDirection(), OCIO::TRANSFORM_DIR_INVERSE);
+    op = ops[7];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[8]; // log to raw
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::LogType);
+    lg = OCIO_DYNAMIC_POINTER_CAST<const OCIO::LogOpData>(op->data());
+    OCIO_CHECK_ASSERT(lg);
+    OCIO_CHECK_EQUAL(lg->getDirection(), OCIO::TRANSFORM_DIR_INVERSE);
+    op = ops[9];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops[10];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+
+    // Compare to vd_graded_2 that should be identical (only diference is that
+    // it's defined using to_reference instead of from_reference)
+    OCIO::ConstColorSpaceRcPtr dstColorSpace2;
+    OCIO_CHECK_NO_THROW(dstColorSpace2 = config->getColorSpace("vd_graded_2"));
+
+    OCIO::OpRcPtrVec ops2;
+    OCIO_CHECK_NO_THROW(BuildColorSpaceOps(ops2, *config, config->getCurrentContext(),
+                                           dstColorSpace2, srcColorSpace, false));
+    OCIO_REQUIRE_EQUAL(ops2.size(), 11);
+    OCIO_CHECK_NO_THROW(ops2.validate());
+    op = ops2[0];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops2[1];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops2[2]; // vd to raw
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::GammaType);
+    gm = OCIO_DYNAMIC_POINTER_CAST<const OCIO::GammaOpData>(op->data());
+    OCIO_CHECK_ASSERT(gm);
+    OCIO_CHECK_EQUAL(gm->getDirection(), OCIO::TRANSFORM_DIR_FORWARD);
+    op = ops2[3]; // raw to log
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::LogType);
+    lg = OCIO_DYNAMIC_POINTER_CAST<const OCIO::LogOpData>(op->data());
+    OCIO_CHECK_ASSERT(lg);
+    OCIO_CHECK_EQUAL(lg->getDirection(), OCIO::TRANSFORM_DIR_FORWARD);
+    op = ops2[4];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops2[5];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops2[6]; // look
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::CDLType);
+    cdl = OCIO_DYNAMIC_POINTER_CAST<const OCIO::CDLOpData>(op->data());
+    OCIO_CHECK_ASSERT(cdl);
+    OCIO_CHECK_EQUAL(cdl->getDirection(), OCIO::TRANSFORM_DIR_INVERSE);
+    op = ops2[7];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops2[8]; // log to raw
+    OCIO_REQUIRE_EQUAL(op->data()->getType(), OCIO::OpData::LogType);
+    lg = OCIO_DYNAMIC_POINTER_CAST<const OCIO::LogOpData>(op->data());
+    OCIO_CHECK_ASSERT(lg);
+    OCIO_CHECK_EQUAL(lg->getDirection(), OCIO::TRANSFORM_DIR_INVERSE);
+    op = ops2[9];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+    op = ops2[10];
+    OCIO_CHECK_ASSERT(op->isNoOpType());
+}
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