refactor glbuild.AppendFloats API

Author: soypat

examples/npt-flange/flange.go

@@ -92,8 +92,9 @@ func scene() (gleval.SDF3, error) {
 
 	pipe, _ := threads.Nut(threads.NutParms{
 		Thread: npt,
-		Style:  threads.NutCircular,
+		Style:  threads.NutKnurl,
 	})
+	return makeSDF(pipe)
 	// Base plate which goes bolted to joint.
 	flange, _ = gsdf.NewCylinder(flangeD/2, flangeH, flangeH/8)
 	// Make through-hole in flange bottom.

forge/threads/threads.go

@@ -84,13 +84,13 @@ func Screw(length float32, thread Threader) (glbuild.Shader3D, error) {
 		return nil, err
 	}
 	params := thread.ThreadParams()
-	s := screw{}
-	s.thread = tsdf
-	s.pitch = params.Pitch
-	s.length = length / 2
-	s.length *= 1 + 1e-3
-	s.taper = params.Taper
-	s.lead = -s.pitch * float32(params.Starts)
+	s := screw{
+		thread: tsdf,
+		pitch:  params.Pitch,
+		lead:   -params.Pitch * float32(params.Starts),
+		length: length / 2,
+		taper:  params.Taper,
+	}
 	return &s, nil
 }
 
@@ -104,6 +104,7 @@ func (s *screw) ForEach2DChild(userData any, fn func(any, *glbuild.Shader2D) err
 
 func (s *screw) AppendShaderName(b []byte) []byte {
 	b = append(b, "screw_"...)
+	b = glbuild.AppendFloats(b, 0, 'n', 'd', s.pitch, s.lead, s.length, s.taper)
 	b = s.thread.AppendShaderName(b)
 	return b
 }

glbuild/glbuild.go

@@ -195,7 +195,7 @@ func (p *Programmer) writeShaders(w io.Writer, nodes []Shader) (n int, err error
 			if bodyHash == gotBodyHash {
 				continue // Shader already written and is identical, skip.
 			}
-			return n, fmt.Errorf("duplicate %T shader name %q", node, name)
+			return n, fmt.Errorf("duplicate %T shader name %q w/ body:\n%s", node, name, body)
 		} else {
 			p.names[nameHash] = bodyHash // Not found, add it.
 		}
@@ -448,7 +448,7 @@ func AppendVec3Decl(b []byte, name string, v ms3.Vec) []byte {
 	b = append(b, name...)
 	b = append(b, "=vec3("...)
 	arr := v.Array()
-	b = AppendFloats(b, arr[:], ',', '-', '.')
+	b = AppendFloats(b, ',', '-', '.', arr[:]...)
 	b = append(b, ')', ';', '\n')
 	return b
 }
@@ -458,7 +458,7 @@ func AppendVec2Decl(b []byte, name string, v ms2.Vec) []byte {
 	b = append(b, name...)
 	b = append(b, "=vec2("...)
 	arr := v.Array()
-	b = AppendFloats(b, arr[:], ',', '-', '.')
+	b = AppendFloats(b, ',', '-', '.', arr[:]...)
 	b = append(b, ')', ';', '\n')
 	return b
 }
@@ -509,7 +509,7 @@ func AppendFloat(b []byte, v float32, neg, decimal byte) []byte {
 	return b[:end]
 }
 
-func AppendFloats(b []byte, s []float32, sep, neg, decimal byte) []byte {
+func AppendFloats(b []byte, sep, neg, decimal byte, s ...float32) []byte {
 	for i, v := range s {
 		b = AppendFloat(b, v, neg, decimal)
 		if sep != 0 && i != len(s)-1 {
@@ -714,12 +714,22 @@ func (nos2 *nameOverloadShader2D) Evaluate(pos []ms2.Vec, dist []float32, userDa
 }
 
 func hash(b []byte, in uint64) uint64 {
+	// Leaving md5 here since we may need to revert to
+	// a more entropic hash to avoid collisions...
+	// though I don't think it'll be necessary.
+	// var result [16]byte
+	// h := md5.New()
+	// h.Write(b)
+	// h.Sum(result[:0])
+	// x1 := binary.LittleEndian.Uint64(result[:])
+	// x2 := binary.LittleEndian.Uint64(result[8:])
+	// return x1 ^ x2 ^ in
 	x := in
 	for len(b) >= 8 {
-		x = x ^ binary.LittleEndian.Uint64(b)
+		x ^= binary.LittleEndian.Uint64(b)
 		x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9
 		x = (x ^ (x >> 27)) * 0x94d049bb133111eb
-		x = x ^ (x >> 31)
+		x ^= x >> 31
 		b = b[8:]
 	}
 	for i := range b {

gsdf.go

@@ -82,7 +82,7 @@ func vecappend(b []byte, v ms3.Vec, sep, neg, decimal byte) []byte {
 }
 
 func sliceappend(b []byte, s []float32, sep, neg, decimal byte) []byte {
-	return glbuild.AppendFloats(b, s, sep, neg, decimal)
+	return glbuild.AppendFloats(b, sep, neg, decimal, s...)
 }
 
 func appendDistanceDecl(b []byte, s glbuild.Shader, name, input string) []byte {