finite repeat operation + drop center point in sdf

derived it all on my own :D

to work correctly, center point as argument to the sdf needs to be removed. Instead, it can be set with by subtracting the position vector from the ray position

shaders/shader.fs

@@ -38,13 +38,13 @@ phongdata phongBox2 = phongdata(vec3(0.0, 0.0, 1.0), vec3(0.0, 0.0, 1.0), vec3(0
 phongdata phongLightBox = phongdata(lightColor, lightColor, lightColor,  256.0);
 
 // START OF SDFs
-float sdfSphere(in vec3 point, in vec3 center, float r)
+float sdfSphere(in vec3 point, float r)
 {
-    return length(point - center) - r;
+    return length(point) - r;
 }
 
-float sdfBox(in vec3 point, in vec3 center, in vec3 b){
-  vec3 q = abs(point - center) - b;
+float sdfBox(in vec3 point, in vec3 b){
+  vec3 q = abs(point) - b;
   return length(max(q,0.0)) + min(max(q.x,max(q.y,q.z)),0.0);
 }
 
@@ -81,47 +81,49 @@ phong opDifference( phong d1, phong d2 ) {
     else return d2;
 }
 
+//works well if bounding box of object < replength
+//reps is the number of times the pattern gets repeated on each axis in each direction (e.g. 1 -> 1 up and 1 down)
+vec3 opFiniteRepeat(vec3 pos, vec3 start, vec3 reps, vec3 replength){
+    vec3 d = round((pos - start) / replength);
+    vec3 r = clamp(d, -reps, reps);
+    return start + r * replength;
+}
+
+// Repeat exactly reps times across each axis (e.g. 1 means ONLY one repeatition across the given axis, NOT 1 up and 1 down)
+vec3 opFiniteRepeat2(in vec3 pos, in vec3 start, in vec3 reps, in vec3 replength){    
+    vec3 m = mod(reps, 2); // 0 if even, 1 if odd
+    vec3 m1 = vec3(1.0) - m; //1 if even , 0 if odd
+    
+    vec3 s = vec3(start+0.5*m1*replength);
+
+    vec3 d = round((pos-s) / replength);
+
+    vec3 r1 = (reps-m)*0.5;
+    vec3 r = clamp(d, -r1, r1 - m1 ); //m - vec3(1.0) should be the same;
+
+    return pos-s-r*replength;
+}
+
 vec3 s = vec3(0.0);
 vec3 r = vec3(3.0, 5.0, 2.0);
-vec3 rl = vec3(2.0, 1.0, 3.0);
-vec3 l = r*rl*0.5;
+vec3 rl = vec3(4.0, 2.0, 4.0);
 
 phong sdfScene(in vec3 p){
-    return opUnion( 
-        opUnion(
-            opUnion(
-                opUnion(
-                    phong(phongSphere, sdfSphere(p, vec3(0.0), 1)), 
-                    phong(phongBox1, sdfBox(p, vec3(2.0, 0.0, 0.0), vec3(0.8)))
-                ),
-                opUnion(
-                    opDifference(
-                        phong(phongBox1, sdfBox(p, vec3(-3.5, 3.5, 0.0), vec3(0.5))),
-                        phong(phongSphere, sdfSphere(p, vec3(-4.0, 4.0, 0.0), 1))
+    return  opUnion(
+            opSmoothUnion(
+                phong(phongSphere, sdfSphere(opFiniteRepeat2(p, vec3(0.0, sin(2*u_time), 0.0), r, rl), 0.4)),
+                phong(phongBox1, 
+                    sdfBox(opFiniteRepeat2(p, s, r, rl), 
+                            vec3(0.5, 0.1, 0.5) 
+                        )
                     ),
-                    opDifference(
-                        phong(phongSphere, sdfSphere(p, vec3(-4.0, 8.0, 0.0), 0.75+ 0.25 * (1+sin(2*u_time)))),
-                        phong(phongBox1, sdfBox(p, vec3(-4.0, 8.0, 0.0), vec3(0.8)))
-                    )
-                )
+                0.4
             ),
-            opUnion(
-                opIntersection(
-                    phong(phongSphere, sdfSphere(p, vec3(0.0, 4.0, 0.0), 1)), 
-                    phong(phongBox1, sdfBox(p, vec3(0.0, 4.5, 0.0), vec3(1)))
-                ),
-                opSmoothUnion(
-                    phong(phongBox2, sdfBox(p, vec3(0.0, 0.0, 6.0), vec3(3.0, 0.2, 3.0)) ),
-                    phong(phongSphere, sdfSphere(p, vec3(0.0, 1.0+sin(u_time), 6.0), 1)),
-                    0.5
-                )
+            opDifference(
+                phong(phongSphere, sdfSphere(p-vec3(0.0, 5.0, 0.0), 0.25 + 0.25* (1+sin(u_time)))),
+                phong(phongBox2, sdfBox(p-vec3(0.0, 5.0, 0.0), vec3(0.5)))
             )
-        ),
-        opUnion(
-            phong(phongBox2, sdfBox(p, vec3(5.0, 0.0, 0.0), vec3(2.0, 1.0, 0.5))),
-            phong(phongLightBox, sdfBox(p, lightPos, vec3(0.1)))
-        )
-    );
+        );
 }
 // END OF SDFs