Enhance sparkle effects and specular calculations for holographic styles; adjust gains and thresholds for improved visual fidelity

Signed-off-by: Hans Kokx <hans.d.kokx@gmail.com>

shaders/shiny_card.frag

@@ -287,16 +287,22 @@ void main() {
   // Highlight uses stretched UVs so glare spans the full widget area.
   float highlightDistance = length(uv - (center + (uTilt * 0.35)));
   float specularMask = pow(max(0.0, 1.0 - highlightDistance * 2.6), 3.2);
-  vec3 specular = vec3(specularMask) * uSpecular * (0.4 + 0.6 * tiltMag);
 
+  bool isHolographicSilver = uStyle < 0.5;
   bool isCrackedIce = uStyle >= 0.5 && uStyle < 1.5;
-  float sparkleGridScale = isCrackedIce ? 7.0 : 18.0;
+  bool isSilverMosaic = uStyle >= 1.5 && uStyle < 2.5;
+
+  float prismaticGain = isHolographicSilver ? 1.10 : (isCrackedIce ? 1.00 : (isSilverMosaic ? 1.30 : 1.55));
+  float sparkleGain = isHolographicSilver ? 1.00 : (isCrackedIce ? 0.55 : (isSilverMosaic ? 0.80 : 0.70));
+  float specularGain = isHolographicSilver ? 1.00 : (isCrackedIce ? 1.35 : (isSilverMosaic ? 1.15 : 1.50));
+
+  float sparkleGridScale = isCrackedIce ? 7.0 : (isSilverMosaic ? 14.0 : 18.0);
   
   // Sparkle grid uses aspect-corrected coordinates to avoid stretching.
   vec2 sparkleGrid = aspectUV * sparkleGridScale;
   vec2 grid = floor(sparkleGrid);
   
-  float rarityThreshold = isCrackedIce ? 0.965 : 0.83;
+  float rarityThreshold = isCrackedIce ? 0.965 : (isSilverMosaic ? 0.88 : 0.83);
   float rarity = step(rarityThreshold, hash(grid + 0.31));
   
   vec3 sparkle = vec3(0.0);
@@ -318,12 +324,12 @@ void main() {
         shapeMask = sparkleShapeMask(cell, grid);
       }
       
-      float sparklePower = isCrackedIce ? 4.8 : 3.2;
+      float sparklePower = isCrackedIce ? 4.8 : (isSilverMosaic ? 3.8 : 3.2);
-      float sparkleIntensity = isCrackedIce ? 0.25 : 1.0;
+      float sparkleIntensity = isCrackedIce ? 0.25 : (isSilverMosaic ? 0.55 : 1.0);
       float sparkleChroma = isCrackedIce ? 0.20 : 0.35;
       float sparkleMask = pow(alignment, sparklePower) * twinkle * rarity * shapeMask;
       vec3 sparkleColor = mix(vec3(1.0), rainbow(sparkleHash + dot(uTilt, vec2(0.2, -0.15)), 0.55, 1.0), sparkleChroma);
-      sparkle = sparkleColor * sparkleMask * uSparkle * sparkleIntensity;
+      sparkle = sparkleColor * sparkleMask * uSparkle * sparkleIntensity * sparkleGain;
     }
   }
 
@@ -348,13 +354,19 @@ void main() {
   float tiltLighting = mix(0.86, 1.20, pow(directional, 1.2));
   chromaAdjusted *= tiltLighting;
 
+  float edgeSpec = pow(1.0 - directional, 2.2);
+  vec3 specular = vec3(specularMask) * (0.3 + 0.7 * edgeSpec) * uSpecular * (0.35 + 0.65 * tiltMag) * specularGain;
+
+  float prismaticPhase = dot(aspectUV, vec2(3.6, -2.1)) + dot(uTilt, vec2(0.9, -0.7)) + uTime * 0.04;
+  vec3 prismaticTint = rainbow(prismaticPhase, 0.72, 1.0) * uPrismatic * prismaticGain * (0.08 + 0.14 * edgeSpec);
+  
   float microStrength = isCrackedIce ? 0.08 : 0.18;
   
   // Micro diffraction uses aspect-corrected UVs to keep grain isotropic.
   float microMask = 0.5 + 0.5 * sin(dot(aspectUV, vec2(137.0, 57.0)) + noise(aspectUV * 14.0) * 4.0 + dot(uTilt, vec2(9.0, 4.0)) * 2.0);
   vec3 microShimmer = rainbow(noise(aspectUV * 10.0) + dot(uTilt, vec2(0.4, -0.3)) * 0.3, 0.65, 1.0) * microMask * uDiffraction * microStrength;
   
-  vec3 styleColor = chromaAdjusted + microShimmer + (specular * 0.15) + sparkle;
+  vec3 styleColor = chromaAdjusted + microShimmer + prismaticTint + (specular * 0.22) + sparkle;
   vec3 mappedColor = styleColor / (1.0 + styleColor * 0.3);
   float luma = dot(mappedColor, vec3(0.299, 0.587, 0.114));
   vec3 vibrantColor = mix(vec3(luma), mappedColor, 1.4);