Move the occupiedCompressedImageDataSize() helper to the GL library.

It's used only there and only to supply a silly argument to a broken API.
Unfortunately back when adding this utility in 2015 I didn't document
what was it for, which initially made me think it's there for some
suspicious reason. Well, the reason is suspicious, but for an entirely
different reason.

src/Magnum/GL/AbstractTexture.cpp

@@ -44,6 +44,7 @@
 #ifndef MAGNUM_TARGET_WEBGL
 #include "Magnum/GL/Implementation/DebugState.h"
 #endif
+#include "Magnum/GL/Implementation/imageProperties.h"
 #include "Magnum/GL/Implementation/RendererState.h"
 #include "Magnum/GL/Implementation/State.h"
 #include "Magnum/GL/Implementation/TextureState.h"
@@ -2173,7 +2174,7 @@ void AbstractTexture::DataHelper<1>::setCompressedImage(AbstractTexture& texture
     Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
     texture.bindInternal();
-    glCompressedTexImage1D(texture._target, level, GLenum(compressedPixelFormat(image.format())), image.size()[0], 0, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
+    glCompressedTexImage1D(texture._target, level, GLenum(compressedPixelFormat(image.format())), image.size()[0], 0, Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
 }
 
 void AbstractTexture::DataHelper<1>::setImage(AbstractTexture& texture, const GLint level, const TextureFormat internalFormat, BufferImage1D& image) {
@@ -2187,7 +2188,7 @@ void AbstractTexture::DataHelper<1>::setCompressedImage(AbstractTexture& texture
     image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
     texture.bindInternal();
-    glCompressedTexImage1D(texture._target, level, GLenum(image.format()), image.size()[0], 0, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.dataSize()), nullptr);
+    glCompressedTexImage1D(texture._target, level, GLenum(image.format()), image.size()[0], 0, Implementation::occupiedCompressedImageDataSize(image, image.dataSize()), nullptr);
 }
 
 void AbstractTexture::DataHelper<1>::setSubImage(AbstractTexture& texture, const GLint level, const Math::Vector<1, GLint>& offset, const ImageView1D& image) {
@@ -2199,7 +2200,7 @@ void AbstractTexture::DataHelper<1>::setSubImage(AbstractTexture& texture, const
 void AbstractTexture::DataHelper<1>::setCompressedSubImage(AbstractTexture& texture, const GLint level, const Math::Vector<1, GLint>& offset, const CompressedImageView1D& image) {
     Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    Context::current().state().texture.compressedSubImage1DImplementation(texture, level, offset, image.size(), compressedPixelFormat(image.format()), image.data(), Magnum::Implementation::occupiedCompressedImageDataSize(image, image.data().size()));
+    Context::current().state().texture.compressedSubImage1DImplementation(texture, level, offset, image.size(), compressedPixelFormat(image.format()), image.data(), Implementation::occupiedCompressedImageDataSize(image, image.data().size()));
 }
 
 void AbstractTexture::DataHelper<1>::setSubImage(AbstractTexture& texture, const GLint level, const Math::Vector<1, GLint>& offset, BufferImage1D& image) {
@@ -2211,7 +2212,7 @@ void AbstractTexture::DataHelper<1>::setSubImage(AbstractTexture& texture, const
 void AbstractTexture::DataHelper<1>::setCompressedSubImage(AbstractTexture& texture, const GLint level, const Math::Vector<1, GLint>& offset, CompressedBufferImage1D& image) {
     image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    Context::current().state().texture.compressedSubImage1DImplementation(texture, level, offset, image.size(), image.format(), nullptr, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.dataSize()));
+    Context::current().state().texture.compressedSubImage1DImplementation(texture, level, offset, image.size(), image.format(), nullptr, Implementation::occupiedCompressedImageDataSize(image, image.dataSize()));
 }
 #endif
 
@@ -2233,7 +2234,7 @@ void AbstractTexture::DataHelper<2>::setCompressedImage(AbstractTexture& texture
     #endif
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
     texture.bindInternal();
-    glCompressedTexImage2D(target, level, GLenum(compressedPixelFormat(image.format())), image.size().x(), image.size().y(), 0, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
+    glCompressedTexImage2D(target, level, GLenum(compressedPixelFormat(image.format())), image.size().x(), image.size().y(), 0, Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
 }
 
 #ifndef MAGNUM_TARGET_GLES2
@@ -2248,7 +2249,7 @@ void AbstractTexture::DataHelper<2>::setCompressedImage(AbstractTexture& texture
     image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
     texture.bindInternal();
-    glCompressedTexImage2D(target, level, GLenum(image.format()), image.size().x(), image.size().y(), 0, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.dataSize()), nullptr);
+    glCompressedTexImage2D(target, level, GLenum(image.format()), image.size().x(), image.size().y(), 0, Implementation::occupiedCompressedImageDataSize(image, image.dataSize()), nullptr);
 }
 #endif
 
@@ -2269,7 +2270,7 @@ void AbstractTexture::DataHelper<2>::setCompressedSubImage(AbstractTexture& text
     Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
     #endif
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    Context::current().state().texture.compressedSubImage2DImplementation(texture, level, offset, image.size(), compressedPixelFormat(image.format()), image.data(), Magnum::Implementation::occupiedCompressedImageDataSize(image, image.data().size()));
+    Context::current().state().texture.compressedSubImage2DImplementation(texture, level, offset, image.size(), compressedPixelFormat(image.format()), image.data(), Implementation::occupiedCompressedImageDataSize(image, image.data().size()));
 }
 
 #ifndef MAGNUM_TARGET_GLES2
@@ -2282,7 +2283,7 @@ void AbstractTexture::DataHelper<2>::setSubImage(AbstractTexture& texture, const
 void AbstractTexture::DataHelper<2>::setCompressedSubImage(AbstractTexture& texture, const GLint level, const Vector2i& offset, CompressedBufferImage2D& image) {
     image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    Context::current().state().texture.compressedSubImage2DImplementation(texture, level, offset, image.size(), image.format(), nullptr, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.dataSize()));
+    Context::current().state().texture.compressedSubImage2DImplementation(texture, level, offset, image.size(), image.format(), nullptr, Implementation::occupiedCompressedImageDataSize(image, image.dataSize()));
 }
 #endif
 
@@ -2306,9 +2307,9 @@ void AbstractTexture::DataHelper<3>::setCompressedImage(AbstractTexture& texture
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
     texture.bindInternal();
     #ifndef MAGNUM_TARGET_GLES2
-    glCompressedTexImage3D(texture._target, level, GLenum(compressedPixelFormat(image.format())), image.size().x(), image.size().y(), image.size().z(), 0, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
+    glCompressedTexImage3D(texture._target, level, GLenum(compressedPixelFormat(image.format())), image.size().x(), image.size().y(), image.size().z(), 0, Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
     #else
-    glCompressedTexImage3DOES(texture._target, level, GLenum(compressedPixelFormat(image.format())), image.size().x(), image.size().y(), image.size().z(), 0, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
+    glCompressedTexImage3DOES(texture._target, level, GLenum(compressedPixelFormat(image.format())), image.size().x(), image.size().y(), image.size().z(), 0, Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
     #endif
 }
 #endif
@@ -2325,7 +2326,7 @@ void AbstractTexture::DataHelper<3>::setCompressedImage(AbstractTexture& texture
     image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
     texture.bindInternal();
-    glCompressedTexImage3D(texture._target, level, GLenum(image.format()), image.size().x(), image.size().y(), image.size().z(), 0, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.dataSize()), nullptr);
+    glCompressedTexImage3D(texture._target, level, GLenum(image.format()), image.size().x(), image.size().y(), image.size().z(), 0, Implementation::occupiedCompressedImageDataSize(image, image.dataSize()), nullptr);
 }
 #endif
 
@@ -2347,7 +2348,7 @@ void AbstractTexture::DataHelper<3>::setCompressedSubImage(AbstractTexture& text
     Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
     #endif
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    Context::current().state().texture.compressedSubImage3DImplementation(texture, level, offset, image.size(), compressedPixelFormat(image.format()), image.data(), Magnum::Implementation::occupiedCompressedImageDataSize(image, image.data().size()));
+    Context::current().state().texture.compressedSubImage3DImplementation(texture, level, offset, image.size(), compressedPixelFormat(image.format()), image.data(), Implementation::occupiedCompressedImageDataSize(image, image.data().size()));
 }
 #endif
 
@@ -2361,7 +2362,7 @@ void AbstractTexture::DataHelper<3>::setSubImage(AbstractTexture& texture, const
 void AbstractTexture::DataHelper<3>::setCompressedSubImage(AbstractTexture& texture, const GLint level, const Vector3i& offset, CompressedBufferImage3D& image) {
     image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    Context::current().state().texture.compressedSubImage3DImplementation(texture, level, offset, image.size(), image.format(), nullptr, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.dataSize()));
+    Context::current().state().texture.compressedSubImage3DImplementation(texture, level, offset, image.size(), image.format(), nullptr, Implementation::occupiedCompressedImageDataSize(image, image.dataSize()));
 }
 #endif
 

src/Magnum/GL/CMakeLists.txt

@@ -105,6 +105,7 @@ set(MagnumGL_PRIVATE_HEADERS
     Implementation/ContextState.h
     Implementation/compressedPixelFormatMapping.hpp
     Implementation/FramebufferState.h
+    Implementation/imageProperties.h
     Implementation/maxTextureSize.h
     Implementation/MeshState.h
     Implementation/QueryState.h

src/Magnum/GL/CubeMapTexture.cpp

@@ -38,6 +38,7 @@
 #endif
 #include "Magnum/GL/Context.h"
 #include "Magnum/GL/PixelFormat.h"
+#include "Magnum/GL/Implementation/imageProperties.h"
 #include "Magnum/GL/Implementation/maxTextureSize.h"
 #include "Magnum/GL/Implementation/RendererState.h"
 #include "Magnum/GL/Implementation/State.h"
@@ -560,7 +561,7 @@ CubeMapTexture& CubeMapTexture::setCompressedSubImage(const Int level, const Vec
 
     Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    glCompressedTextureSubImage3D(_id, level, offset.x(), offset.y(), offset.z(), image.size().x(), image.size().y(), image.size().z(), GLenum(compressedPixelFormat(image.format())), Magnum::Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
+    glCompressedTextureSubImage3D(_id, level, offset.x(), offset.y(), offset.z(), image.size().x(), image.size().y(), image.size().z(), GLenum(compressedPixelFormat(image.format())), Implementation::occupiedCompressedImageDataSize(image, image.data().size()), image.data());
     return *this;
 }
 
@@ -571,7 +572,7 @@ CubeMapTexture& CubeMapTexture::setCompressedSubImage(const Int level, const Vec
 
     image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    glCompressedTextureSubImage3D(_id, level, offset.x(), offset.y(), offset.z(), image.size().x(), image.size().y(), image.size().z(), GLenum(image.format()), Magnum::Implementation::occupiedCompressedImageDataSize(image, image.dataSize()), nullptr);
+    glCompressedTextureSubImage3D(_id, level, offset.x(), offset.y(), offset.z(), image.size().x(), image.size().y(), image.size().z(), GLenum(image.format()), Implementation::occupiedCompressedImageDataSize(image, image.dataSize()), nullptr);
     return *this;
 }
 #endif
@@ -603,7 +604,7 @@ CubeMapTexture& CubeMapTexture::setCompressedSubImage(const CubeMapCoordinate co
     Buffer::unbindInternal(Buffer::TargetHint::PixelUnpack);
     #endif
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    Context::current().state().texture.cubeCompressedSubImageImplementation(*this, coordinate, level, offset, image.size(), compressedPixelFormat(image.format()), image.data(), Magnum::Implementation::occupiedCompressedImageDataSize(image, image.data().size()));
+    Context::current().state().texture.cubeCompressedSubImageImplementation(*this, coordinate, level, offset, image.size(), compressedPixelFormat(image.format()), image.data(), Implementation::occupiedCompressedImageDataSize(image, image.data().size()));
     return *this;
 }
 
@@ -611,7 +612,7 @@ CubeMapTexture& CubeMapTexture::setCompressedSubImage(const CubeMapCoordinate co
 CubeMapTexture& CubeMapTexture::setCompressedSubImage(const CubeMapCoordinate coordinate, const Int level, const Vector2i& offset, CompressedBufferImage2D& image) {
     image.buffer().bindInternal(Buffer::TargetHint::PixelUnpack);
     Context::current().state().renderer.applyPixelStorageUnpack(image.storage());
-    Context::current().state().texture.cubeCompressedSubImageImplementation(*this, coordinate, level, offset, image.size(), image.format(), nullptr, Magnum::Implementation::occupiedCompressedImageDataSize(image, image.dataSize()));
+    Context::current().state().texture.cubeCompressedSubImageImplementation(*this, coordinate, level, offset, image.size(), image.format(), nullptr, Implementation::occupiedCompressedImageDataSize(image, image.dataSize()));
     return *this;
 }
 #endif

src/Magnum/GL/Implementation/imageProperties.h

@@ -0,0 +1,54 @@
+#ifndef Magnum_GL_Implementation_imageProperties_h
+#define Magnum_GL_Implementation_imageProperties_h
+/*
+    This file is part of Magnum.
+
+    Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019,
+                2020, 2021, 2022, 2023, 2024, 2025
+              Vladimír Vondruš <mosra@centrum.cz>
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included
+    in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+*/
+
+#include "Magnum/Implementation/ImageProperties.h"
+
+namespace Magnum { namespace GL { namespace Implementation {
+
+/* Used in compressed image upload functions. Unlike what common sense and
+   various robustness extensions would imply, where the size is the memory
+   range occupied by the data given various pixel storage parameters, it's
+   instead expected to stupidly be just the image dimensions (*not* row length
+   etc) in whole blocks. Which has absolutely NO RELATION to the actual memory
+   and thus is completely useless for enforcing any memory security in the
+   driver, it's only there to bully users. My suspicion is that whoever did
+   ARB_compressed_texture_pixel_storage (which makes skip, row length etc.
+   possible for compressed formats) didn't bother thinking about what the
+   existing parameter is for, just left it unchanged, and nobody else in the
+   commitee bothered either.
+
+   In case the block size properties aren't set, the actual image data size is
+   used as a backup, which might still be correct in most cases. */
+template<class T> std::size_t occupiedCompressedImageDataSize(const T& image, std::size_t dataSize) {
+    return image.storage().compressedBlockSize().product() && image.storage().compressedBlockDataSize()
+        ? Magnum::Implementation::compressedImageDataOffsetSizeFor(image, image.size()).second : dataSize;
+}
+
+}}}
+
+#endif

src/Magnum/Implementation/ImageProperties.h

@@ -117,12 +117,6 @@ template<std::size_t dimensions, class T> std::size_t compressedImageDataSizeFor
     return r.first + r.second;
 }
 
-/* Use in compressed image upload functions */
-template<class T> std::size_t occupiedCompressedImageDataSize(const T& image, std::size_t dataSize) {
-    return image.storage().compressedBlockSize().product() && image.storage().compressedBlockDataSize()
-        ? compressedImageDataOffsetSizeFor(image, image.size()).second : dataSize;
-}
-
 template<std::size_t dimensions, class T> std::ptrdiff_t pixelStorageSkipOffsetFor(const T& image, const Math::Vector<dimensions, Int>& size) {
     return image.storage().dataProperties(image.pixelSize(), Vector3i::pad(size, 1)).first.sum();
 }