magical new dots

src/game/shaders/frag.sc

@@ -7,6 +7,7 @@ $input v_wpos
 
 SAMPLER2D(s_texColor, 0);
 SAMPLER3D(s_ditherSampler, 1);
+SAMPLER2D(s_rampSampler, 2);
 uniform vec4 u_time;
 uniform vec4 u_testColor;
 
@@ -29,19 +30,35 @@ vec3 desaturate(vec3 color)
 
 void main()
 {
+	// setup
+	float globalScale = 6.0;
 	float testRadius = 30.0;
 	float testSpeed = 1.0;
 	vec3 testOffset = vec3(0.0, 0.0, 50.0);
 	float3 lightPos = vec3(sin(u_time.x * testSpeed) * testRadius, 5.0, cos(u_time.x * testSpeed) * testRadius);
+	vec2 inputUv = v_uv0;
+	vec3 texColor = u_testColor.x > 0.1 ? u_testColor.xyz : texture2D(s_texColor, v_uv0).xyz;
+
+	// lighting
 	// float brightness = calcBrightness(lightPos, v_wpos, v_normal);
-	float brightness = calcBrightnessDirectional(vec3(0.5, 0.3, 1.0), v_normal);
-	brightness = 1.0;
-	// brightness = sin(u_time.x) * 0.5 + 0.5;
+	float brightness = lerp(0.5, 0.9, calcBrightnessDirectional(vec3(0.5, 0.3, 1.0), v_normal));
+	// float brightness = 0.5;
+	// brightness = lerp(0.2, 1.0, sin(u_time.x) * 0.5 + 0.5);
+	
+	// constants
+	float dotsPerSide = 2;
+	float dotsTotal = dotsPerSide * dotsPerSide;
+	float xRes = 32;
+	float invXRes = 1 / xRes;
+	float zRes = dotsTotal;
+	float invZRes = 1 / zRes;
+	
+	float2 rampLookupUv = vec2((0.5 * invXRes + (1 - invXRes) * brightness), 0.5);
+	float brightnessCurve = texture2D(s_rampSampler, rampLookupUv).r;
 	
 	// Magic dot frequency calculation
-	float baseScale = 8.0;
-	float2 dx = ddx(v_uv0 * baseScale);
-	float2 dy = ddy(v_uv0 * baseScale);
+	float2 dx = ddx(inputUv);
+	float2 dy = ddy(inputUv);
 	float2x2 mat = float2x2(dx, dy);
 	float4 vectorized = float4(dx, dy);
 	float qq = dot(vectorized, vectorized);
@@ -51,23 +68,34 @@ void main()
 	float2 freq = sqrt(float2(qq + discriminant, qq - discriminant) / 2.0);
 
 	// Figuring out how many dots we want
-	float spacing = freq.y * exp2(2.0);
-	spacing = 1.0 / spacing;
-	spacing *= brightness; // TODO: check reference to see how to calculate this!
-	float spacingLog = max(log2(spacing), 0.0);
+	float scaleExp = exp2(globalScale);
+	float spacing = freq.y * scaleExp;
+
+	float brightnessSpacingMultiplier = pow(brightnessCurve * 2 + 0.001, -(1 - 0.5));
+	// float brightnessSpacingMultiplier = 1;
+	spacing *= brightnessSpacingMultiplier;
+	
+	float spacingLog = log2(spacing);
 	int patternScaleLevel = floor(spacingLog);
 	float patternFractional = spacingLog - patternScaleLevel;
-	vec2 uv = v_uv0 * exp2(patternScaleLevel);
-
-	float dotsTotal = 4;
-	float subLayer = lerp(0.25 * dotsTotal, dotsTotal, patternFractional);
-	subLayer = (subLayer - 0.5) / dotsTotal;
+	vec2 uv = inputUv / exp2(patternScaleLevel);
 	
-	vec4 circleSample = texture3D(s_ditherSampler, vec3(uv, subLayer));	
-	float circleVal = circleSample.x < 0.75 ? 0.1 : 0.9;
+	// patternFractional *= patternFractional;
+	// patternFractional = smoothstep(0, 1, patternFractional);
+	float subLayer = lerp(0.25 * dotsTotal, dotsTotal, 1 - patternFractional);
+	subLayer = (subLayer - 0.5) * invZRes;
 	
-	// Coloring
-	vec3 texColor = u_testColor.x > 0.1 ? u_testColor.xyz : texture2D(s_texColor, v_uv0).xyz;
-	vec3 finalColor = texColor * vec3(circleVal, circleVal, circleVal);
+	float pattern = texture3D(s_ditherSampler, vec3(uv, subLayer)).r;	
+	
+	float contrast = 12 * scaleExp * brightnessSpacingMultiplier * 0.1;
+	contrast *= pow(freq.y / freq.x, 1.0);
+	float baseVal = lerp(0.5, brightness, saturate(1.05 / (1 + contrast)));
+	float threshold = 1 - brightnessCurve + 0.6;
+	
+	vec3 thresholds = threshold.xxx / texColor;
+	// vec3 finalColor = saturate((pattern - thresholds) * contrast + baseVal);
+	vec3 finalColor = saturate((pattern - thresholds) * contrast + baseVal);
 	gl_FragColor = vec4(finalColor, 1.0);
+	// gl_FragColor = vec4(finalColor * 0.8 + subLayer * 0.2, 1.0);
+	// gl_FragColor = vec4(finalColor * 0.8 + vec3(uv % 1, 0.0) * 0.2, 1.0);
 }