Add better color output

src/drawables/shapes/circle.ts

@@ -9,17 +9,15 @@ export class Circle extends Drawable {
           uniform vec2 circleCenters[CIRCLE_COUNT];
           uniform float circleRadii[CIRCLE_COUNT];
 
-          void circleMinDistance(inout float minDistance, inout float color) {
-              float myMinDistance = maxMinDistance;
-              for (int i = 0; i < CIRCLE_COUNT; i++) {
-                  float dist = distance(circleCenters[i], position) - circleRadii[i];
-                  myMinDistance = min(myMinDistance, dist);
-              }
-              minDistance = min(minDistance, myMinDistance);
-              color = mix(1.0 / {paletteSize}, color, step(
-                distanceNdcPixelSize + SURFACE_OFFSET, 
-                myMinDistance
-              ));
+          float circleMinDistance(vec2 target, out float colorIndex) {
+            colorIndex = 2.0;
+            float minDistance = 1000.0;
+            for (int i = 0; i < CIRCLE_COUNT; i++) {
+              float dist = distance(circleCenters[i], target) - circleRadii[i];
+              minDistance = min(minDistance, dist);
+            }
+
+            return minDistance;
           }
         `,
       distanceFunctionName: 'circleMinDistance',

src/drawables/shapes/inverted-tunnel.ts

@@ -13,10 +13,11 @@ export class InvertedTunnel extends Drawable {
         uniform float fromRadii[INVERTED_TUNNEL_COUNT];
         uniform float toRadii[INVERTED_TUNNEL_COUNT];
 
-        void invertedTunnelMinDistance(inout float minDistance, inout float color) {
-          float myMinDistance = -minDistance;
+        float invertedTunnelMinDistance(vec2 target, out float colorIndex) {
+          float minDistance = 1000.0;
+
           for (int i = 0; i < INVERTED_TUNNEL_COUNT; i++) {
-            vec2 targetFromDelta = position - froms[i];
+            vec2 targetFromDelta = target - froms[i];
 
             float h = clamp(
                 dot(targetFromDelta, toFromDeltas[i])
@@ -30,14 +31,10 @@ export class InvertedTunnel extends Drawable {
               targetFromDelta, toFromDeltas[i] * h
             );
 
-            myMinDistance = min(myMinDistance, currentDistance);
+            minDistance = min(minDistance, currentDistance);
           }
 
-          color = mix(0.0, color, step(
-            distanceNdcPixelSize + SURFACE_OFFSET,
-            -myMinDistance
-          ));
-          minDistance = -myMinDistance;
+          return -minDistance;
         }
       `,
       distanceFunctionName: 'invertedTunnelMinDistance',

src/drawables/shapes/tunnel.ts

@@ -13,10 +13,12 @@ export class Tunnel extends Drawable {
         uniform float fromRadii[TUNNEL_COUNT];
         uniform float toRadii[TUNNEL_COUNT];
 
-        void tunnelMinDistance(inout float minDistance, inout float color) {
-          float myMinDistance = minDistance;
+        float tunnelMinDistance(vec2 target, out float colorIndex) {
+          colorIndex = 1.0;
+
+          float minDistance = 1000.0;
           for (int i = 0; i < TUNNEL_COUNT; i++) {
-            vec2 targetFromDelta = position - froms[i];
+            vec2 targetFromDelta = target - froms[i];
             
             float h = clamp(
                 dot(targetFromDelta, toFromDeltas[i])
@@ -30,14 +32,10 @@ export class Tunnel extends Drawable {
               targetFromDelta, toFromDeltas[i] * h
             );
 
-            myMinDistance = min(myMinDistance, currentDistance);
+            minDistance = min(minDistance, currentDistance);
           }
 
-          color = mix(2.0 / {paletteSize}, color, step(
-            distanceNdcPixelSize + SURFACE_OFFSET,
-            myMinDistance
-          ));
-          minDistance = min(minDistance, myMinDistance);
+          return minDistance;
         }
       `,
       distanceFunctionName: 'tunnelMinDistance',

src/graphics/graphics-library/program/uniform-array-autoscaling-program.ts

@@ -135,7 +135,22 @@ export class UniformArrayAutoScalingProgram implements IProgram {
           return '';
         }
 
-        return `${descriptors[i].sdf!.distanceFunctionName}(minDistance, color);`;
+        return `
+          #ifndef NOT_EMPTY
+          #define NOT_EMPTY
+          #endif
+
+          objectMinDistance = ${
+            descriptors[i].sdf!.distanceFunctionName
+          }(position, objectColor);
+
+          color = mix(objectColor / {paletteSize}, color, step(
+            distanceNdcPixelSize + SURFACE_OFFSET, 
+            objectMinDistance
+          ));
+
+          minDistance = min(minDistance, objectMinDistance);
+        `;
       })
       .join('\n');
   }

src/graphics/rendering/shaders/distance-fs-100.glsl

@@ -13,11 +13,17 @@ varying vec2 position;
 {declarations}
 
 void main() {
-    float minDistance = maxMinDistance;
+    float minDistance = abs(maxMinDistance);
     float color = 0.0;
 
+    float objectMinDistance, objectColor;
+
     {functionCalls}
     
+    #ifndef NOT_EMPTY
+    minDistance = maxMinDistance;
+    #endif
+
     // minDistance / 2.0: NDC to UV scale
     gl_FragColor = vec4(minDistance / 2.0, color, 0.0, 0.0);
 }

src/graphics/rendering/shaders/distance-fs.glsl

@@ -15,11 +15,17 @@ in vec2 position;
 out vec2 fragmentColor;
 
 void main() {
-    float minDistance = maxMinDistance;
+    float minDistance = abs(maxMinDistance);
     float color = 0.0;
 
+    float objectMinDistance, objectColor;
+
     {functionCalls}
 
+    #ifndef NOT_EMPTY
+    minDistance = maxMinDistance;
+    #endif
+
     // minDistance / 2.0: NDC to UV scale
     fragmentColor = vec2(minDistance / 2.0, color);
 }