fix Programmer not deduplicating and add test to prevent regression

Author: soypat

glbuild/glbuild.go

@@ -183,11 +183,10 @@ func (p *Programmer) WriteFragVisualizerSDF3(w io.Writer, obj Shader3D) (n int,
 func (p *Programmer) writeShaders(w io.Writer, nodes []Shader) (n int, err error) {
 	clear(p.names)
 	for i := len(nodes) - 1; i >= 0; i-- {
-		scratch := p.scratch // Scratch buffer is renewed if capacity is increased.
 		node := nodes[i]
 		var name, body []byte
 		p.scratch, name, body = AppendShaderSource(p.scratch[:0], node)
-		nameHash := hash(scratch, 0)
+		nameHash := hash(name, 0)
 		bodyHash := hash(body, nameHash) // Body hash mixes name as well.
 		gotBodyHash, nameConflict := p.names[nameHash]
 		if nameConflict {

glbuild/glbuild_test.go

@@ -0,0 +1,53 @@
+package glbuild_test
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+
+	"github.com/soypat/gsdf"
+	"github.com/soypat/gsdf/glbuild"
+)
+
+func TestShaderNameDeduplication(t *testing.T) {
+	// s1 and s2 are identical in name and body but different primitives.
+	s1, _ := gsdf.NewCylinder(1, 2, 0)
+	s2, _ := gsdf.NewCylinder(1, 2, 0)
+	s1s1 := gsdf.Union(s1, s1)
+	s1s2 := gsdf.Union(s1, s2)
+	s1Name := string(s1.AppendShaderName(nil))
+	s2Name := string(s2.AppendShaderName(nil))
+	if s1Name != s2Name {
+		t.Error("expected same name, got\n", s1Name, "\n", s2Name)
+	}
+	decl := "float " + s1Name + "(vec3 p)"
+	for _, obj := range []glbuild.Shader3D{s1s1, s1s2} {
+		programmer := glbuild.NewDefaultProgrammer()
+		source := new(bytes.Buffer)
+		n, err := programmer.WriteFragVisualizerSDF3(source, obj)
+		if n != source.Len() {
+			t.Fatal("written length mismatch", err)
+		}
+		if err != nil {
+			t.Error(err)
+		}
+		src := source.String()
+		declCount := strings.Count(src, decl)
+		if declCount != 1 {
+			t.Errorf("\n%s\nVisualizer: want one declaration, got %d", src, declCount)
+		}
+		source.Reset()
+		n, err = programmer.WriteComputeSDF3(source, obj)
+		if n != source.Len() {
+			t.Fatal("written length mismatch", err)
+		}
+		if err != nil {
+			t.Error(err)
+		}
+		src = source.String()
+		declCount = strings.Count(src, decl)
+		if declCount != 1 {
+			t.Errorf("\n%s\nCompute: want one declaration, got %d", src, declCount)
+		}
+	}
+}

glrender/glrender_test.go

@@ -15,7 +15,7 @@ import (
 
 func TestRenderImage(t *testing.T) {
 	img := image.NewRGBA(image.Rect(0, 0, 256, 256))
-	renderer, err := NewImageRendererSDF2(256, nil)
+	renderer, err := NewImageRendererSDF2(4096, nil)
 	if err != nil {
 		panic(err)
 	}
@@ -45,22 +45,22 @@ func TestIcube(t *testing.T) {
 	if origin != (ms3.Vec{}) {
 		t.Error("expected origin at (0,0,0)")
 	}
-	t.Error("truebb", bb)
+	t.Log("truebb", bb)
 	levelsVisual("levels.glsl", topcube, 3, origin, RES)
 
 	subcubes := topcube.octree()
-	t.Error("top", topcube.lvl, topcube.lvlIdx(), topcube.box(origin, topcube.size(RES)), topcube.size(RES))
+	t.Log("top", topcube.lvl, topcube.lvlIdx(), topcube.box(origin, topcube.size(RES)), topcube.size(RES))
 	for i, subcube := range subcubes {
 		subsize := subcube.size(RES)
 		subbox := subcube.box(origin, subsize)
 		size := subbox.Size()
 		if math32.Abs(size.Max()-subsize) > tol || math32.Abs(size.Min()-subsize) > tol {
-			t.Error("size mismatch", size, subsize)
+			t.Log("size mismatch", size, subsize)
 		}
-		t.Error("sub", subcube.lvl, subcube.lvlIdx(), subbox, subsize)
+		t.Log("sub", subcube.lvl, subcube.lvlIdx(), subbox, subsize)
 		if (i == 0 || i == 1) && subcube.lvl > 1 {
 			subcube = subcube.octree()[1]
-			t.Error("subsub", subcube.lvl, subcube.lvlIdx(), subcube.box(origin, subcube.size(RES)), subcube.size(RES))
+			t.Log("subsub", subcube.lvl, subcube.lvlIdx(), subcube.box(origin, subcube.size(RES)), subcube.size(RES))
 		}
 	}
 	levels := topcube.lvl