use maxMip+1 instead

fix bugs during virtual texture `free`

Author: devshgraphicsprogramming

include/nbl/asset/utils/ICPUVirtualTexture.h

@@ -457,11 +457,10 @@ class ICPUVirtualTexture final : public IVirtualTexture<ICPUImageView, ICPUSampl
         const E_FORMAT format = getFormatInLayer(_addr.pgTab_layer);
         ICPUVTResidentStorage* storage = static_cast<ICPUVTResidentStorage*>(getStorageForFormatClass(getFormatClass(format)));
         if (!storage)
-            return nullptr;
+            return false;
 
         //free physical pages
         VkExtent3D extent = {static_cast<uint32_t>(_addr.origsize_x), static_cast<uint32_t>(_addr.origsize_y), 1u};
-        const uint32_t levelCount = _addr.maxMip+1u;
 
 #ifdef _NBL_DEBUG
         CFillImageFilter::state_type fill;
@@ -478,7 +477,7 @@ class ICPUVirtualTexture final : public IVirtualTexture<ICPUImageView, ICPUSampl
         std::fill(m_addrsArray->begin(), m_addrsArray->end(), IVTResidentStorage::phys_pg_addr_alctr_t::invalid_address);
 
         auto* const bufptr = reinterpret_cast<uint8_t*>(m_pageTable->getBuffer()->getPointer());
-        for (uint32_t i = 0u; i < levelCount; ++i)
+        for (uint32_t i=0u; i<core::max(_addr.maxMip,1u); ++i)
         {
             const uint32_t w = neededPageCountForSide(extent.width, i);
             const uint32_t h = neededPageCountForSide(extent.height, i);

include/nbl/asset/utils/IVirtualTexture.h

@@ -139,7 +139,7 @@ class IVirtualTexture : public core::IReferenceCounted, public IVirtualTextureBa
         uint64_t pgTab_x : 8;
         uint64_t pgTab_y : 8;
         uint64_t pgTab_layer : 8;
-        uint64_t maxMip : 4; // value 0x0fu means, the texture takes only 1 page of physical storage (miptail)
+        uint64_t maxMip : 4; // this is number of mip-maps plus 1 that the texture will have in the virtual texture (before the mip-tail)
         uint64_t wrap_x : 2;
         uint64_t wrap_y : 2;
 
@@ -210,8 +210,8 @@ class IVirtualTexture : public core::IReferenceCounted, public IVirtualTextureBa
 		texData.pgTab_y = _offset.y;
         texData.pgTab_layer = _offset.z;
 
-        const uint32_t maxMip = _mipCount - 1u - m_pgSzxy_log2;
-        assert(static_cast<int32_t>(maxMip) >= -1); // only textures of size at least half page size must be packed
+        const uint32_t maxMip = _mipCount-m_pgSzxy_log2;
+        assert(static_cast<int32_t>(maxMip) >= 0); // only textures of size at least half page size must be packed
         texData.maxMip = maxMip;
 
         texData.wrap_x = SMasterTextureData::ETC_to_EWM(_wrapu);
@@ -720,7 +720,7 @@ class IVirtualTexture : public core::IReferenceCounted, public IVirtualTextureBa
 
     bool validateAliasCreation(const SMasterTextureData& _addr, E_FORMAT _viewingFormat, const IImage::SSubresourceRange& _subresRelativeToMaster)
     {
-        if (_subresRelativeToMaster.baseMipLevel+_subresRelativeToMaster.levelCount > _addr.maxMip+1u)
+        if (_subresRelativeToMaster.baseMipLevel+_subresRelativeToMaster.levelCount > _addr.maxMip)
             return false;
         return true;
     }

include/nbl/builtin/glsl/virtual_texturing/impl_functions.glsl

@@ -26,10 +26,9 @@ uvec2 nbl_glsl_unpackWrapModes(in uvec2 texData)
 {
     return (texData >> uvec2(28u, 30u))& uvec2(0x03u);
 }
-int nbl_glsl_unpackMaxMipInVT(in uvec2 texData)
+uint nbl_glsl_unpackMaxMipInVT(in uvec2 texData)
 {
-    uint mm = (texData.y >> 24) & 0x0fu;
-    return mm == 0x0fu ? -1 : int(mm);
+    return bitfieldExtract(texData.y,24,4);
 }
 vec3 nbl_glsl_unpackVirtualUV(in uvec2 texData)
 {
@@ -87,7 +86,7 @@ vec3 nbl_glsl_vTexture_helper(in uint formatID, in vec3 virtualUV, in int clippe
 
 #if _NBL_VT_FLOAT_VIEWS_COUNT
 // textureGrad emulation
-vec4 nbl_glsl_vTextureGrad_impl(in uint formatID, in vec3 virtualUV, in mat2 dOriginalScaledUV, in int originalMaxFullMip)
+vec4 nbl_glsl_vTextureGrad_impl(in uint formatID, in vec3 virtualUV, in mat2 dOriginalScaledUV, in uint originalMaxFullMip)
 {
 	// returns what would have been `textureGrad(originalTexture,gOriginalUV[0],gOriginalUV[1])
 	// https://www.khronos.org/registry/vulkan/specs/1.2-extensions/html/chap15.html#textures-normalized-operations
@@ -119,15 +118,15 @@ vec4 nbl_glsl_vTextureGrad_impl(in uint formatID, in vec3 virtualUV, in mat2 dOr
 	// are we performing minification
 	bool positiveLoD = LoD>0.0;
 	// magnification samples LoD 0, else clip to max representable in VT
-	int clippedLoD = positiveLoD ? min(LoD_high,originalMaxFullMip):0; // originalMaxFullMip is always -1 in case of no miplevel taking at least 1 full page
-    clippedLoD = originalMaxFullMip < 0 ? 0 : clippedLoD;
+	int clippedLoD = positiveLoD ? min(LoD_high,int(originalMaxFullMip)-1):0; // originalMaxFullMip is always -1 in case of no miplevel taking at least 1 full page
+    clippedLoD = originalMaxFullMip<1u ? 0 : clippedLoD;
 
 	// if minification is being performaed then get tail position
 	int levelInTail = LoD_high-clippedLoD;
 	// have to do trilinear only if doing minification AND larger than 1x1 footprint
 	bool haveToDoTrilinear = levelInTail<int(_NBL_VT_IMPL_PAGE_SZ_LOG2) && positiveLoD;
 	levelInTail = haveToDoTrilinear ? levelInTail:(positiveLoD ? int(_NBL_VT_IMPL_PAGE_SZ_LOG2):0);
-    levelInTail += (originalMaxFullMip < 0) ? 1 : 0;
+    levelInTail += originalMaxFullMip<1u ? 1 : 0;
 
 	// get the higher resolution mip-map level
 	vec3 hiPhysCoord = nbl_glsl_vTexture_helper(formatID,virtualUV,clippedLoD,levelInTail);
@@ -136,7 +135,7 @@ vec4 nbl_glsl_vTextureGrad_impl(in uint formatID, in vec3 virtualUV, in mat2 dOr
 	// speculative if (haveToDoTrilinear)
 	{
 		// now we have absolute guarantees that both LoD_high and LoD_low are in the valid original mip range
-		bool highNotInLastFull = originalMaxFullMip>=0 && LoD_high<originalMaxFullMip;
+		bool highNotInLastFull = originalMaxFullMip>=1u && LoD_high<(int(originalMaxFullMip)-1);
 		clippedLoD = highNotInLastFull ? (clippedLoD+1):clippedLoD;
 		levelInTail = highNotInLastFull ? levelInTail:(levelInTail+1);
         levelInTail = min(levelInTail, int(_NBL_VT_IMPL_PAGE_SZ_LOG2));
@@ -193,7 +192,7 @@ vec4 nbl_glsl_vTextureGrad(in uvec2 _texData, in vec2 uv, in mat2 dUV)
 #endif //_NBL_VT_FLOAT_VIEWS_COUNT
 
 #if _NBL_VT_INT_VIEWS_COUNT
-ivec4 nbl_glsl_iVTextureLod_impl(in uint formatID, in vec3 virtualUV, in uint lod, in int originalMaxFullMip)
+ivec4 nbl_glsl_iVTextureLod_impl(in uint formatID, in vec3 virtualUV, in uint lod, in uint originalMaxFullMip)
 {
     int nonnegativeLod = int(lod);
     int clippedLoD = min(nonnegativeLod,originalMaxFullMip);
@@ -235,7 +234,7 @@ ivec4 nbl_glsl_iVTextureLod(in uvec2 _texData, in vec2 uv, in uint lod)
 #endif //_NBL_VT_INT_VIEWS_COUNT
 
 #if _NBL_VT_UINT_VIEWS_COUNT
-uvec4 nbl_glsl_uVTextureLod_impl(in uint formatID, in vec3 virtualUV, in uint lod, in int originalMaxFullMip)
+uvec4 nbl_glsl_uVTextureLod_impl(in uint formatID, in vec3 virtualUV, in uint lod, in uint originalMaxFullMip)
 {
     int nonnegativeLod = int(lod);
     int clippedLoD = min(nonnegativeLod,originalMaxFullMip);