maxwell_to_vk: Approach GL_CLAMP closer to the GL spec

The OpenGL spec defines GL_CLAMP's formula similarly to CLAMP_TO_EDGE
and CLAMP_TO_BORDER depending on the filter mode used. It doesn't
exactly behave like this, but it's the closest we can get with what
Vulkan offers without emulating it by injecting shader code.

src/video_core/renderer_vulkan/maxwell_to_vk.cpp

@@ -44,7 +44,8 @@ vk::SamplerMipmapMode MipmapMode(Tegra::Texture::TextureMipmapFilter mipmap_filt
     return {};
 }
 
-vk::SamplerAddressMode WrapMode(Tegra::Texture::WrapMode wrap_mode) {
+vk::SamplerAddressMode WrapMode(Tegra::Texture::WrapMode wrap_mode,
+                                Tegra::Texture::TextureFilter filter) {
     switch (wrap_mode) {
     case Tegra::Texture::WrapMode::Wrap:
         return vk::SamplerAddressMode::eRepeat;
@@ -55,10 +56,15 @@ vk::SamplerAddressMode WrapMode(Tegra::Texture::WrapMode wrap_mode) {
     case Tegra::Texture::WrapMode::Border:
         return vk::SamplerAddressMode::eClampToBorder;
     case Tegra::Texture::WrapMode::Clamp:
-        // TODO(Rodrigo): GL_CLAMP was removed as of OpenGL 3.1, to implement GL_CLAMP, we can use
-        // eClampToBorder to get the border color of the texture, and then sample the edge to
-        // manually mix them. However the shader part of this is not yet implemented.
-        return vk::SamplerAddressMode::eClampToBorder;
+        // TODO(Rodrigo): Emulate GL_CLAMP properly
+        switch (filter) {
+        case Tegra::Texture::TextureFilter::Nearest:
+            return vk::SamplerAddressMode::eClampToEdge;
+        case Tegra::Texture::TextureFilter::Linear:
+            return vk::SamplerAddressMode::eClampToBorder;
+        }
+        UNREACHABLE();
+        return vk::SamplerAddressMode::eClampToEdge;
     case Tegra::Texture::WrapMode::MirrorOnceClampToEdge:
         return vk::SamplerAddressMode::eMirrorClampToEdge;
     case Tegra::Texture::WrapMode::MirrorOnceBorder:

src/video_core/renderer_vulkan/maxwell_to_vk.h

@@ -23,7 +23,8 @@ vk::Filter Filter(Tegra::Texture::TextureFilter filter);
 
 vk::SamplerMipmapMode MipmapMode(Tegra::Texture::TextureMipmapFilter mipmap_filter);
 
-vk::SamplerAddressMode WrapMode(Tegra::Texture::WrapMode wrap_mode);
+vk::SamplerAddressMode WrapMode(Tegra::Texture::WrapMode wrap_mode,
+                                Tegra::Texture::TextureFilter filter);
 
 vk::CompareOp DepthCompareFunction(Tegra::Texture::DepthCompareFunc depth_compare_func);
 

src/video_core/renderer_vulkan/vk_sampler_cache.cpp

@@ -46,9 +46,10 @@ UniqueSampler VKSamplerCache::CreateSampler(const Tegra::Texture::TSCEntry& tsc)
         {}, MaxwellToVK::Sampler::Filter(tsc.mag_filter),
         MaxwellToVK::Sampler::Filter(tsc.min_filter),
         MaxwellToVK::Sampler::MipmapMode(tsc.mipmap_filter),
-        MaxwellToVK::Sampler::WrapMode(tsc.wrap_u), MaxwellToVK::Sampler::WrapMode(tsc.wrap_v),
-        MaxwellToVK::Sampler::WrapMode(tsc.wrap_p), tsc.GetLodBias(), has_anisotropy,
-        max_anisotropy, tsc.depth_compare_enabled,
+        MaxwellToVK::Sampler::WrapMode(tsc.wrap_u, tsc.mag_filter),
+        MaxwellToVK::Sampler::WrapMode(tsc.wrap_v, tsc.mag_filter),
+        MaxwellToVK::Sampler::WrapMode(tsc.wrap_p, tsc.mag_filter), tsc.GetLodBias(),
+        has_anisotropy, max_anisotropy, tsc.depth_compare_enabled,
         MaxwellToVK::Sampler::DepthCompareFunction(tsc.depth_compare_func), tsc.GetMinLod(),
         tsc.GetMaxLod(), vk_border_color.value_or(vk::BorderColor::eFloatTransparentBlack),
         unnormalized_coords);