code: Add texture sampling option (#7118)

* This replaces the nearest neighbour filter that shouldn't have existed in the first place

src/video_core/host_shaders/CMakeLists.txt

@@ -7,7 +7,6 @@ set(SHADER_FILES
     format_reinterpreter/rgba4_to_rgb5a1.frag
     format_reinterpreter/vulkan_d24s8_to_rgba8.comp
     texture_filtering/bicubic.frag
-    texture_filtering/nearest_neighbor.frag
     texture_filtering/refine.frag
     texture_filtering/scale_force.frag
     texture_filtering/xbrz_freescale.frag

src/video_core/host_shaders/texture_filtering/nearest_neighbor.frag

@@ -1,15 +0,0 @@
-// Copyright 2023 Citra Emulator Project
-// Licensed under GPLv2 or any later version
-// Refer to the license.txt file included.
-
-//? #version 430 core
-precision mediump float;
-
-layout(location = 0) in vec2 tex_coord;
-layout(location = 0) out vec4 frag_color;
-
-layout(binding = 2) uniform sampler2D input_texture;
-
-void main() {
-    frag_color = texture(input_texture, tex_coord);
-}

src/video_core/rasterizer_cache/rasterizer_cache.h

@@ -361,10 +361,25 @@ typename T::Sampler& RasterizerCache<T>::GetSampler(SamplerId sampler_id) {
 template <class T>
 typename T::Sampler& RasterizerCache<T>::GetSampler(
     const Pica::TexturingRegs::TextureConfig& config) {
+    using TextureFilter = Pica::TexturingRegs::TextureConfig::TextureFilter;
+
+    const auto get_filter = [](TextureFilter filter) {
+        switch (Settings::values.texture_sampling.GetValue()) {
+        case Settings::TextureSampling::GameControlled:
+            return filter;
+        case Settings::TextureSampling::NearestNeighbor:
+            return TextureFilter::Nearest;
+        case Settings::TextureSampling::Linear:
+            return TextureFilter::Linear;
+        default:
+            return filter;
+        }
+    };
+
     const SamplerParams params = {
-        .mag_filter = config.mag_filter,
-        .min_filter = config.min_filter,
-        .mip_filter = config.mip_filter,
+        .mag_filter = get_filter(config.mag_filter),
+        .min_filter = get_filter(config.min_filter),
+        .mip_filter = get_filter(config.mip_filter),
         .wrap_s = config.wrap_s,
         .wrap_t = config.wrap_t,
         .border_color = config.border_color.raw,

src/video_core/renderer_opengl/gl_blit_helper.cpp

@@ -15,7 +15,6 @@
 #include "video_core/host_shaders/full_screen_triangle_vert.h"
 #include "video_core/host_shaders/texture_filtering/bicubic_frag.h"
 #include "video_core/host_shaders/texture_filtering/mmpx_frag.h"
-#include "video_core/host_shaders/texture_filtering/nearest_neighbor_frag.h"
 #include "video_core/host_shaders/texture_filtering/refine_frag.h"
 #include "video_core/host_shaders/texture_filtering/scale_force_frag.h"
 #include "video_core/host_shaders/texture_filtering/x_gradient_frag.h"
@@ -58,7 +57,6 @@ BlitHelper::BlitHelper(const Driver& driver_)
     : driver{driver_}, linear_sampler{CreateSampler(GL_LINEAR)},
       nearest_sampler{CreateSampler(GL_NEAREST)}, bicubic_program{CreateProgram(
                                                       HostShaders::BICUBIC_FRAG)},
-      nearest_program{CreateProgram(HostShaders::NEAREST_NEIGHBOR_FRAG)},
       scale_force_program{CreateProgram(HostShaders::SCALE_FORCE_FRAG)},
       xbrz_program{CreateProgram(HostShaders::XBRZ_FREESCALE_FRAG)},
       mmpx_program{CreateProgram(HostShaders::MMPX_FRAG)}, gradient_x_program{CreateProgram(
@@ -175,9 +173,6 @@ bool BlitHelper::Filter(Surface& surface, const VideoCore::TextureBlit& blit) {
     case TextureFilter::Bicubic:
         FilterBicubic(surface, blit);
         break;
-    case TextureFilter::NearestNeighbor:
-        FilterNearest(surface, blit);
-        break;
     case TextureFilter::ScaleForce:
         FilterScaleForce(surface, blit);
         break;
@@ -257,14 +252,6 @@ void BlitHelper::FilterBicubic(Surface& surface, const VideoCore::TextureBlit& b
     Draw(bicubic_program, surface.Handle(), draw_fbo.handle, blit.dst_level, blit.dst_rect);
 }
 
-void BlitHelper::FilterNearest(Surface& surface, const VideoCore::TextureBlit& blit) {
-    const OpenGLState prev_state = OpenGLState::GetCurState();
-    SCOPE_EXIT({ prev_state.Apply(); });
-    state.texture_units[2].texture_2d = surface.Handle(0);
-    SetParams(nearest_program, surface.RealExtent(false), blit.src_rect);
-    Draw(nearest_program, surface.Handle(), draw_fbo.handle, blit.dst_level, blit.dst_rect);
-}
-
 void BlitHelper::FilterScaleForce(Surface& surface, const VideoCore::TextureBlit& blit) {
     const OpenGLState prev_state = OpenGLState::GetCurState();
     SCOPE_EXIT({ prev_state.Apply(); });

src/video_core/renderer_opengl/gl_blit_helper.h

@@ -33,20 +33,13 @@ public:
 
 private:
     void FilterAnime4K(Surface& surface, const VideoCore::TextureBlit& blit);
-
     void FilterBicubic(Surface& surface, const VideoCore::TextureBlit& blit);
-
-    void FilterNearest(Surface& surface, const VideoCore::TextureBlit& blit);
-
     void FilterScaleForce(Surface& surface, const VideoCore::TextureBlit& blit);
-
     void FilterXbrz(Surface& surface, const VideoCore::TextureBlit& blit);
-
     void FilterMMPX(Surface& surface, const VideoCore::TextureBlit& blit);
 
     void SetParams(OGLProgram& program, const VideoCore::Extent& src_extent,
                    Common::Rectangle<u32> src_rect);
-
     void Draw(OGLProgram& program, GLuint dst_tex, GLuint dst_fbo, u32 dst_level,
               Common::Rectangle<u32> dst_rect);
 
@@ -59,7 +52,6 @@ private:
     OGLSampler nearest_sampler;
 
     OGLProgram bicubic_program;
-    OGLProgram nearest_program;
     OGLProgram scale_force_program;
     OGLProgram xbrz_program;
     OGLProgram mmpx_program;

src/video_core/renderer_vulkan/vk_blit_helper.h

@@ -35,10 +35,7 @@ public:
                        const VideoCore::BufferTextureCopy& copy);
 
 private:
-    /// Creates compute pipelines used for blit
     vk::Pipeline MakeComputePipeline(vk::ShaderModule shader, vk::PipelineLayout layout);
-
-    /// Creates graphics pipelines used for blit
     vk::Pipeline MakeDepthStencilBlitPipeline();
 
 private: