fix: Use more modern span-based set_pixels with OIIO 3.1. (#2042)

Switch CI back to the aswf/ci-osl:2025-clang18.3 container that
has OIIO 3.1, it will work fine with this change.

Signed-off-by: Larry Gritz <[email protected]>

Author: lgritz

.github/workflows/ci.yml

@@ -684,7 +684,7 @@ jobs:
             # select the right runner type and whether tests are run.
             nametag: linux-optix-vfx2025
             runner: ${{ (github.repository_owner == 'AcademySoftwareFoundation' && 'ubuntu-20.04-gpu-t4-4c-16g-176h') || 'ubuntu-latest' }}
-            container: aswf/ci-osl:2025-clang18.2
+            container: aswf/ci-osl:2025-clang18
             cxx_std: 17
             python_ver: "3.11"
             pybind11_ver: v2.11.1

src/testrender/optixraytracer.cpp

@@ -1252,7 +1252,11 @@ OptixRaytracer::finalize_pixel_buffer()
                           reinterpret_cast<void*>(d_output_buffer),
                           m_xres * m_yres * 3 * sizeof(float),
                           cudaMemcpyDeviceToHost));
+#if OIIO_VERSION_GREATER_EQUAL(3, 1, 0)
+    pixelbuf.set_pixels(OIIO::ROI::All(), OIIO::make_cspan(tmp_buff));
+#else
     pixelbuf.set_pixels(OIIO::ROI::All(), OIIO::TypeFloat, tmp_buff.data());
+#endif
 }
 
 

src/testshade/optixgridrender.cpp

@@ -1088,8 +1088,13 @@ OptixGridRenderer::finalize_pixel_buffer()
                           m_xres * m_yres * 3 * sizeof(float),
                           cudaMemcpyDeviceToHost));
     OIIO::ImageBuf* buf = outputbuf(0);
-    if (buf)
+    if (buf) {
+#if OIIO_VERSION_GREATER_EQUAL(3, 1, 0)
+        buf->set_pixels(OIIO::ROI::All(), OIIO::make_cspan(tmp_buff));
+#else
         buf->set_pixels(OIIO::ROI::All(), OIIO::TypeFloat, tmp_buff.data());
+#endif
+    }
 }