Fix a filtering issue, enable this for Fushigi no Dungeon 4.

GPU/Common/GPUStateUtils.h

@@ -59,6 +59,10 @@ bool NeedsTestDiscard();
 bool IsDepthTestEffectivelyDisabled();
 bool IsStencilTestOutputDisabled();
 
+inline bool CanForceBilinear(const GPUgstate &gstate) {
+	return ((!gstate.isColorTestEnabled() || IsColorTestTriviallyTrue()) && (!gstate.isAlphaTestEnabled() || IsAlphaTestTriviallyTrue()));
+}
+
 StencilValueType ReplaceAlphaWithStencilType();
 ReplaceAlphaType ReplaceAlphaWithStencil(ReplaceBlendType replaceBlend);
 ReplaceBlendType ReplaceBlendWithShader(GEBufferFormat bufferFormat);

GPU/Common/ShaderUniforms.cpp

@@ -188,33 +188,39 @@ void BaseUpdateUniforms(UB_VS_FS_Base *ub, uint64_t dirtyUniforms, bool useBuffe
 	}
 
 	if (dirtyUniforms & DIRTY_DEPAL) {
-		int indexMask = gstate.getClutIndexMask();
-		int indexShift = gstate.getClutIndexShift();
-		int indexOffset = gstate.getClutIndexStartPos() >> 4;
-		int format = gstate_c.depalTextureFormat;
-		uint32_t val = BytesToUint32(indexMask, indexShift, indexOffset, format);
-		// NOTE: This must follow similar logic to TextureCacheCommon::GetSamplingParams -
-		// maybe we can share it somehow.
-		// TOOD: Handle replaced textures.
-		bool bilinear = gstate.isMagnifyFilteringEnabled() && !gstate_c.pixelMapped;
-		switch (g_Config.iTexFiltering) {
-		case TEX_FILTER_FORCE_NEAREST:
-			bilinear = false;
-			break;
-		case TEX_FILTER_FORCE_LINEAR:
-			bilinear = true;
-			break;
-		default:
-			break;
-		}
-		if (bilinear) {
-			// Poke in a bilinear filter flag in the top bit.
-			val |= 0x80000000;
-		}
-		ub->depal_mask_shift_off_fmt = val;
+		ub->depal_mask_shift_off_fmt = PackDepalBits();
 	}
 }
 
+uint32_t PackDepalBits() {
+	const int indexMask = gstate.getClutIndexMask();
+	const int indexShift = gstate.getClutIndexShift();
+	const int indexOffset = gstate.getClutIndexStartPos() >> 4;
+	const int format = gstate_c.depalTextureFormat;
+	uint32_t val = BytesToUint32(indexMask, indexShift, indexOffset, format);
+	// NOTE: This must follow similar logic to TextureCacheCommon::GetSamplingParams -
+	// maybe we can share it somehow.
+	// TOOD: Handle replaced textures.
+	bool bilinear = gstate.isMagnifyFilteringEnabled() && !gstate_c.pixelMapped;
+	switch (g_Config.iTexFiltering) {
+	case TEX_FILTER_FORCE_NEAREST:
+		bilinear = false;
+		break;
+	case TEX_FILTER_FORCE_LINEAR:
+		if (CanForceBilinear(gstate)) {
+			bilinear = true;
+		}
+		break;
+	default:
+		break;
+	}
+	if (bilinear) {
+		// Poke in a bilinear filter flag in the top bit.
+		val |= 0x80000000;
+	}
+	return val;
+}
+
 // For "light ubershader" bits.
 // TODO: We pack these bits even when not using ubershader lighting. Maybe not bother.
 uint32_t PackLightControlBits() {

GPU/Common/ShaderUniforms.h

@@ -119,3 +119,4 @@ void LightUpdateUniforms(UB_VS_Lights *ub, uint64_t dirtyUniforms);
 void BoneUpdateUniforms(UB_VS_Bones *ub, uint64_t dirtyUniforms);
 
 uint32_t PackLightControlBits();
+uint32_t PackDepalBits();

GPU/Common/TextureCacheCommon.cpp

@@ -282,8 +282,7 @@ SamplerCacheKey TextureCacheCommon::GetSamplingParams(int maxLevel, const TexCac
 			break;
 		case TEX_FILTER_FORCE_LINEAR:
 			// Override to linear filtering if there's no alpha or color testing going on.
-			if ((!gstate.isColorTestEnabled() || IsColorTestTriviallyTrue()) &&
-				(!gstate.isAlphaTestEnabled() || IsAlphaTestTriviallyTrue())) {
+			if (CanForceBilinear(gstate)) {
 				forceFiltering = TEX_FILTER_FORCE_LINEAR;
 			}
 			break;

GPU/GLES/ShaderManagerGLES.cpp

@@ -374,14 +374,7 @@ void LinkedShader::UpdateUniforms(const ShaderID &vsid, const ShaderLanguageDesc
 		return;
 
 	if (dirty & DIRTY_DEPAL) {
-		int indexMask = gstate.getClutIndexMask();
-		int indexShift = gstate.getClutIndexShift();
-		int indexOffset = gstate.getClutIndexStartPos() >> 4;
-		int format = gstate_c.depalTextureFormat;
-		uint32_t val = BytesToUint32(indexMask, indexShift, indexOffset, format);
-		// Poke in a bilinear filter flag in the top bit.
-		val |= gstate.isMagnifyFilteringEnabled() << 31;
-		render_->SetUniformUI1(&u_depal_mask_shift_off_fmt, val);
+		render_->SetUniformUI1(&u_depal_mask_shift_off_fmt, PackDepalBits());
 	}
 
 	// Set HUD mode

GPU/GPUState.h

@@ -716,4 +716,3 @@ class GPUInterface;
 class GPUCommon;
 
 extern GPUStateCache gstate_c;
-

assets/compat.ini

@@ -2142,6 +2142,6 @@ ULKS46087 = 0.5
 # NPJH50878 = -0.4
 
 [TextureCLUTInShader]
-# See #15251. This drastically reduces the amount of textures decoded by the game, but due to lots of tile modifications
-# the number is still pretty high.
-# NPJH50698 = true
+# Fushigi no Dungeon 4. See #15251. This drastically reduces the amount of textures decoded by the game,
+# but due to lots of tile modifications the number is still pretty high.
+NPJH50698 = true