shader changes & screen quads

src/game/shaders/dither/frag.sc

@@ -0,0 +1,111 @@
+$input v_color0
+$input v_normal
+$input v_uv0
+$input v_wpos
+
+#include "../common.sh"
+
+SAMPLER2D(s_texColor, 0);
+SAMPLER3D(s_ditherSampler, 1);
+SAMPLER2D(s_rampSampler, 2);
+uniform vec4 u_time;
+uniform vec4 u_testColor;
+uniform vec4 u_texInfo;
+uniform vec4 u_baseColor;
+
+float calcBrightness(vec3 lightPos, vec3 vertPos, vec3 normal)
+{
+	vec3 lightDir = normalize(lightPos - vertPos);
+	float diffuse = max(0.0, dot(lightDir, normal));
+	return diffuse * clamp(1.0 - distance(lightPos, vertPos) * 0.01, 0.0, 1.0);
+}
+
+float calcBrightnessDirectional(vec3 sunDir, vec3 normal)
+{
+	return max(0.0, dot(sunDir, normal));
+}
+
+vec3 desaturate(vec3 color)
+{
+	return vec3_splat(dot(color, vec3(0.33, 0.34, 0.33)));
+}
+
+float dither(float brightness, vec2 inputUv)
+{
+	float globalScale = 8;
+	
+	// constants
+	float xRes = u_texInfo.z;
+	float dotsPerSide = xRes / 16;
+	float dotsTotal = dotsPerSide * dotsPerSide;
+	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
+	float2 dx = ddx(inputUv);
+	float2 dy = ddy(inputUv);
+	float2x2 mat = float2x2(dx, dy);
+	float4 vectorized = float4(dx, dy);
+	float qq = dot(vectorized, vectorized);
+	float rr = determinant(mat);
+	float discriminantSqr = max(0.0, qq*qq - 4.0*rr*rr);
+	float discriminant = sqrt(discriminantSqr);	
+	float2 freq = sqrt(float2(qq + discriminant, qq - discriminant) / 2.0);
+
+	// Figuring out how many dots we want
+	float scaleExp = exp2(globalScale);
+	float spacing = freq.y * scaleExp;
+	spacing *= dotsPerSide * 0.125;
+
+	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 = inputUv / exp2(patternScaleLevel);
+	
+	// patternFractional *= patternFractional;
+	// patternFractional = smoothstep(0, 1, patternFractional);
+	float subLayer = lerp(0.25 * dotsTotal, dotsTotal, 1 - patternFractional);
+	subLayer = (subLayer - 0.5) * invZRes;
+	
+	float pattern = texture3D(s_ditherSampler, vec3(uv, subLayer)).r;	
+	
+	float contrast = 2 * 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;
+	
+	return saturate((pattern - threshold) * contrast + baseVal);
+}
+
+void main()
+{
+	// setup
+	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);
+	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 = 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);
+
+	float r = dither(brightness * texColor.r, v_uv0);
+	float g = dither(brightness * texColor.g, v_uv0);
+	float b = dither(brightness * texColor.b, v_uv0);
+	// float3 finalColor = vec3(r, g, b);
+	float3 ditheredColor = dither(brightness, v_uv0);
+	float3 finalColor = mix(u_baseColor, texColor, ditheredColor);
+	gl_FragColor = vec4(finalColor, 1.0);
+	
+}