From fac55fa9e0c876ce7020d3c6649be8eaa6c7388a Mon Sep 17 00:00:00 2001
From: Larry Gritz <lg@larrygritz.com>
Date: Wed, 21 Aug 2024 10:14:14 -0700
Subject: [PATCH] ptex: Store full metadata only at subimage 0, miplevel 0 for
 ptex files. (#4376)

Don't read or store full metadata on every MIP level for every face.
That can really add up! Ptex can only have one set of metadata, the
format itself doesn't allow it to vary from face to face.

Signed-off-by: Larry Gritz <lg@larrygritz.com>
---
 src/ptex.imageio/ptexinput.cpp | 96 ++++++++++++++++++++--------------
 1 file changed, 57 insertions(+), 39 deletions(-)

diff --git a/src/ptex.imageio/ptexinput.cpp b/src/ptex.imageio/ptexinput.cpp
index 4b921c157a..0c34222084 100644
--- a/src/ptex.imageio/ptexinput.cpp
+++ b/src/ptex.imageio/ptexinput.cpp
@@ -66,6 +66,8 @@ class PtexInput final : public ImageInput {
         m_subimage = -1;
         m_miplevel = -1;
     }
+
+    void get_ptex_metadata(PtexMetaData* pmeta);
 };
 
 
@@ -190,6 +192,29 @@ PtexInput::seek_subimage(int subimage, int miplevel)
         wrapmode += "periodic";
     m_spec.attribute("wrapmode", wrapmode);
 
+    // Add the arbitrary metadata. For Ptex, we only add full metadata to the
+    // first MIP level of the first subimage. The PTex format doesn't permit
+    // metadata to differ per-face anyway.
+    if (subimage == 0 && miplevel == 0) {
+        if (PtexMetaData* pmeta = m_ptex->getMetaData()) {
+            get_ptex_metadata(pmeta);
+            pmeta->release();
+        }
+    }
+
+    facedata->release();
+    return true;
+}
+
+
+
+void
+PtexInput::get_ptex_metadata(PtexMetaData* pmeta)
+{
+    if (!pmeta)
+        return;
+
+        // Helper macro to get metadata of a specific type
 #define GETMETA(pmeta, key, ptype, basetype, typedesc, value) \
     {                                                         \
         const ptype* v;                                       \
@@ -199,47 +224,40 @@ PtexInput::seek_subimage(int subimage, int miplevel)
         value    = (const void*)v;                            \
     }
 
-    PtexMetaData* pmeta = m_ptex->getMetaData();
-    if (pmeta) {
-        int n = pmeta->numKeys();
-        for (int i = 0; i < n; ++i) {
-            const char* key = NULL;
-            Ptex::MetaDataType ptype;
-            pmeta->getKey(i, key, ptype);
-            OIIO_DASSERT(key);
-            const char* vchar;
-            const void* value;
-            TypeDesc typedesc;
-            switch (ptype) {
-            case Ptex::mdt_string:
-                pmeta->getValue(key, vchar);
-                value    = &vchar;
-                typedesc = TypeDesc::STRING;
-                break;
-            case Ptex::mdt_int8:
-                GETMETA(pmeta, key, int8_t, TypeDesc::INT8, typedesc, value);
-                break;
-            case Ptex::mdt_int16:
-                GETMETA(pmeta, key, int16_t, TypeDesc::INT16, typedesc, value);
-                break;
-            case Ptex::mdt_int32:
-                GETMETA(pmeta, key, int32_t, TypeDesc::INT32, typedesc, value);
-                break;
-            case Ptex::mdt_float:
-                GETMETA(pmeta, key, float, TypeDesc::FLOAT, typedesc, value);
-                break;
-            case Ptex::mdt_double:
-                GETMETA(pmeta, key, double, TypeDesc::DOUBLE, typedesc, value);
-                break;
-            default: continue;
-            }
-            m_spec.attribute(key, typedesc, value);
+    int n = pmeta->numKeys();
+    for (int i = 0; i < n; ++i) {
+        const char* key = NULL;
+        Ptex::MetaDataType ptype;
+        pmeta->getKey(i, key, ptype);
+        OIIO_DASSERT(key);
+        const char* vchar;
+        const void* value;
+        TypeDesc typedesc;
+        switch (ptype) {
+        case Ptex::mdt_string:
+            pmeta->getValue(key, vchar);
+            value    = &vchar;
+            typedesc = TypeDesc::STRING;
+            break;
+        case Ptex::mdt_int8:
+            GETMETA(pmeta, key, int8_t, TypeDesc::INT8, typedesc, value);
+            break;
+        case Ptex::mdt_int16:
+            GETMETA(pmeta, key, int16_t, TypeDesc::INT16, typedesc, value);
+            break;
+        case Ptex::mdt_int32:
+            GETMETA(pmeta, key, int32_t, TypeDesc::INT32, typedesc, value);
+            break;
+        case Ptex::mdt_float:
+            GETMETA(pmeta, key, float, TypeDesc::FLOAT, typedesc, value);
+            break;
+        case Ptex::mdt_double:
+            GETMETA(pmeta, key, double, TypeDesc::DOUBLE, typedesc, value);
+            break;
+        default: continue;
         }
-        pmeta->release();
+        m_spec.attribute(key, typedesc, value);
     }
-
-    facedata->release();
-    return true;
 }