pica/lighting: only apply Fresnel factor for the last light

2 files changed, 9 insertions, 7 deletions

diff --git a/src/video_core/renderer_opengl/gl_shader_gen.cpp b/src/video_core/renderer_opengl/gl_shader_gen.cpp
index 3f390491a..b5f359da6 100644
--- a/src/video_core/renderer_opengl/gl_shader_gen.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_gen.cpp
@@ -750,7 +750,8 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
         }
 
         // Fresnel
-        if (lighting.lut_fr.enable &&
+        // Note: only the last entry in the light slots applies the Fresnel factor
+        if (light_index == lighting.src_num - 1 && lighting.lut_fr.enable &&
             LightingRegs::IsLightingSamplerSupported(lighting.config,
                                                      LightingRegs::LightingSampler::Fresnel)) {
             // Lookup fresnel LUT value
@@ -759,17 +760,17 @@ static void WriteLighting(std::string& out, const PicaShaderConfig& config) {
                             lighting.lut_fr.type, lighting.lut_fr.abs_input);
             value = "(" + std::to_string(lighting.lut_fr.scale) + " * " + value + ")";
 
-            // Enabled for difffuse lighting alpha component
+            // Enabled for diffuse lighting alpha component
             if (lighting.fresnel_selector == LightingRegs::LightingFresnelSelector::PrimaryAlpha ||
                 lighting.fresnel_selector == LightingRegs::LightingFresnelSelector::Both) {
-                out += "diffuse_sum.a  *= " + value + ";\n";
+                out += "diffuse_sum.a = " + value + ";\n";
             }
 
             // Enabled for the specular lighting alpha component
             if (lighting.fresnel_selector ==
                     LightingRegs::LightingFresnelSelector::SecondaryAlpha ||
                 lighting.fresnel_selector == LightingRegs::LightingFresnelSelector::Both) {
-                out += "specular_sum.a *= " + value + ";\n";
+                out += "specular_sum.a = " + value + ";\n";
             }
         }
 
diff --git a/src/video_core/swrasterizer/lighting.cpp b/src/video_core/swrasterizer/lighting.cpp
index b38964530..5fa748611 100644
--- a/src/video_core/swrasterizer/lighting.cpp
+++ b/src/video_core/swrasterizer/lighting.cpp
@@ -230,7 +230,8 @@ std::tuple<Math::Vec4<u8>, Math::Vec4<u8>> ComputeFragmentsColors(
             d1_lut_value * refl_value * light_config.specular_1.ToVec3f();
 
         // Fresnel
-        if (lighting.config1.disable_lut_fr == 0 &&
+        // Note: only the last entry in the light slots applies the Fresnel factor
+        if (light_index == lighting.max_light_index && lighting.config1.disable_lut_fr == 0 &&
             LightingRegs::IsLightingSamplerSupported(lighting.config0.config,
                                                      LightingRegs::LightingSampler::Fresnel)) {
 
@@ -242,14 +243,14 @@ std::tuple<Math::Vec4<u8>, Math::Vec4<u8>> ComputeFragmentsColors(
             if (lighting.config0.fresnel_selector ==
                     LightingRegs::LightingFresnelSelector::PrimaryAlpha ||
                 lighting.config0.fresnel_selector == LightingRegs::LightingFresnelSelector::Both) {
-                diffuse_sum.a() *= lut_value;
+                diffuse_sum.a() = lut_value;
             }
 
             // Enabled for the specular lighting alpha component
             if (lighting.config0.fresnel_selector ==
                     LightingRegs::LightingFresnelSelector::SecondaryAlpha ||
                 lighting.config0.fresnel_selector == LightingRegs::LightingFresnelSelector::Both) {
-                specular_sum.a() *= lut_value;
+                specular_sum.a() = lut_value;
             }
         }