From 4c2aebedc2fc50bd7b38c5f2ff7c52517ddfedef Mon Sep 17 00:00:00 2001
From: Kevin Ring <kevin@kotachrome.com>
Date: Tue, 5 Nov 2024 18:17:34 +1100
Subject: [PATCH] Eliminate dodgy namespacing of STBIR.

---
 CesiumGltfContent/src/ImageManipulation.cpp   | 20 +++-----
 .../include/CesiumGltfReader/ImageDecoder.h   | 27 +++++++++++
 CesiumGltfReader/src/ImageDecoder.cpp         | 47 +++++++++++++------
 3 files changed, 66 insertions(+), 28 deletions(-)

diff --git a/CesiumGltfContent/src/ImageManipulation.cpp b/CesiumGltfContent/src/ImageManipulation.cpp
index 6a6a7c3fe..e1b368a7a 100644
--- a/CesiumGltfContent/src/ImageManipulation.cpp
+++ b/CesiumGltfContent/src/ImageManipulation.cpp
@@ -1,21 +1,15 @@
 #include <CesiumGltf/ImageAsset.h>
 #include <CesiumGltfContent/ImageManipulation.h>
+#include <CesiumGltfReader/ImageDecoder.h>
 
 #include <cstring>
 
-namespace Cesium {
-// Use STB resize in our own namespace to avoid conflicts from other libs
-#define STBIRDEF
-#include <stb_image_resize2.h>
-#undef STBIRDEF
-} // namespace Cesium
-
-using namespace Cesium;
-
 #define STB_IMAGE_WRITE_STATIC
 #define STB_IMAGE_WRITE_IMPLEMENTATION
 #include <stb_image_write.h>
 
+using namespace CesiumGltfReader;
+
 namespace CesiumGltfContent {
 
 void ImageManipulation::unsafeBlitImage(
@@ -108,16 +102,16 @@ bool ImageManipulation::blitImage(
     }
 
     // Use STB to do the copy / scale
-    stbir_resize_uint8_linear(
-        reinterpret_cast<const unsigned char*>(pSource),
+    ImageDecoder::unsafeResize(
+        pSource,
         sourcePixels.width,
         sourcePixels.height,
         int(bytesPerSourceRow),
-        reinterpret_cast<unsigned char*>(pTarget),
+        pTarget,
         targetPixels.width,
         targetPixels.height,
         int(bytesPerTargetRow),
-        static_cast<stbir_pixel_layout>(target.channels));
+        target.channels);
   }
 
   return true;
diff --git a/CesiumGltfReader/include/CesiumGltfReader/ImageDecoder.h b/CesiumGltfReader/include/CesiumGltfReader/ImageDecoder.h
index c3bb0b300..7e50d4e08 100644
--- a/CesiumGltfReader/include/CesiumGltfReader/ImageDecoder.h
+++ b/CesiumGltfReader/include/CesiumGltfReader/ImageDecoder.h
@@ -68,6 +68,33 @@ class ImageDecoder {
    */
   static std::optional<std::string>
   generateMipMaps(CesiumGltf::ImageAsset& image);
+
+  /**
+   * @brief Resize an image, without validating the provided pointers or ranges.
+   *
+   * @param inputPixels The input image.
+   * @param inputWidth The width of the input image, in pixels.
+   * @param inputHeight The height of the input image, in pixels.
+   * @param inputStrideBytes The stride of the input image, in bytes. Stride is
+   * the number of bytes between successive rows.
+   * @param outputPixels The buffer into which to write the output image.
+   * @param outputWidth The width of the output image, in pixels.
+   * @param outputHeight The height of the otuput image, in pixels.
+   * @param outputStrideBytes The stride of the output image, in bytes. Stride
+   * is the number of bytes between successive rows.
+   * @param channels The number of channels in both the input and output images.
+   * @return True if the resize succeeded, false if it failed.
+   */
+  static bool unsafeResize(
+      const std::byte* pInputPixels,
+      int32_t inputWidth,
+      int32_t inputHeight,
+      int32_t inputStrideBytes,
+      std::byte* pOutputPixels,
+      int32_t outputWidth,
+      int32_t outputHeight,
+      int32_t outputStrideBytes,
+      int32_t channels);
 };
 
 } // namespace CesiumGltfReader
diff --git a/CesiumGltfReader/src/ImageDecoder.cpp b/CesiumGltfReader/src/ImageDecoder.cpp
index fba65b71b..3ec7738c3 100644
--- a/CesiumGltfReader/src/ImageDecoder.cpp
+++ b/CesiumGltfReader/src/ImageDecoder.cpp
@@ -26,23 +26,19 @@
 
 #define STBI_FAILURE_USERMSG
 
-namespace Cesium {
-// Use STB resize in our own namespace to avoid conflicts from other libs
-#define STBIRDEF
-#define STB_IMAGE_RESIZE_IMPLEMENTATION
-#include <stb_image_resize2.h>
-#undef STBIRDEF
-}; // namespace Cesium
-
 #define STB_IMAGE_STATIC
 #define STB_IMAGE_IMPLEMENTATION
+#define STBI_NO_STDIO
+#define STBI_ASSERT(x) CESIUM_ASSERT(x)
 #include <stb_image.h>
-#include <turbojpeg.h>
+
+#define STB_IMAGE_RESIZE_IMPLEMENTATION
+#define STB_IMAGE_RESIZE_STATIC
+#include <stb_image_resize2.h>
 
 namespace CesiumGltfReader {
 
 using namespace CesiumGltf;
-using namespace Cesium;
 
 namespace {
 
@@ -436,17 +432,16 @@ std::optional<std::string> ImageDecoder::generateMipMaps(ImageAsset& image) {
     image.mipPositions[mipIndex].byteOffset = byteOffset;
     image.mipPositions[mipIndex].byteSize = byteSize;
 
-    if (!stbir_resize_uint8_linear(
-            reinterpret_cast<const unsigned char*>(
-                &image.pixelData[lastByteOffset]),
+    if (!ImageDecoder::unsafeResize(
+            &image.pixelData[lastByteOffset],
             lastWidth,
             lastHeight,
             0,
-            reinterpret_cast<unsigned char*>(&image.pixelData[byteOffset]),
+            &image.pixelData[byteOffset],
             mipWidth,
             mipHeight,
             0,
-            static_cast<stbir_pixel_layout>(image.channels))) {
+            image.channels)) {
       // Remove any added mipmaps.
       image.mipPositions.clear();
       image.pixelData.resize(imageByteSize);
@@ -457,4 +452,26 @@ std::optional<std::string> ImageDecoder::generateMipMaps(ImageAsset& image) {
   return std::nullopt;
 }
 
+/*static*/ bool ImageDecoder::unsafeResize(
+    const std::byte* pInputPixels,
+    int32_t inputWidth,
+    int32_t inputHeight,
+    int32_t inputStrideBytes,
+    std::byte* pOutputPixels,
+    int32_t outputWidth,
+    int32_t outputHeight,
+    int32_t outputStrideBytes,
+    int32_t channels) {
+  return stbir_resize_uint8_linear(
+             reinterpret_cast<const unsigned char*>(pInputPixels),
+             inputWidth,
+             inputHeight,
+             inputStrideBytes,
+             reinterpret_cast<unsigned char*>(pOutputPixels),
+             outputWidth,
+             outputHeight,
+             outputStrideBytes,
+             static_cast<stbir_pixel_layout>(channels)) != nullptr;
+}
+
 } // namespace CesiumGltfReader