Added PDF Generation

internal/layout/layout.go

@@ -4,25 +4,14 @@ import (
 	"printer.backend/internal/model"
 )
 
-// Footprint returns the physical width and height one item occupies on the plate (mm).
-// Includes bleed on all sides and the item's margin as a safe zone.
-func Footprint(spec model.ItemSpec) (width, height float64) {
-	w := spec.SizeMM + 2*spec.BleedMM + 2*spec.MarginMM
-	return w, w
-}
-
-// CellPitch returns width and height of one grid cell (footprint + spacing between items).
-func CellPitch(spec model.ItemSpec, spacingMM float64) (width, height float64) {
-	fw, fh := Footprint(spec)
-	return fw + spacingMM, fh + spacingMM
-}
-
 // Pack computes the maximum grid of items that fit on the plate.
+// Item spacing uses the SVG viewport size (spec.SizeMM); bleed/margin/padding live inside the template.
 func Pack(plate model.Plate, spec model.ItemSpec, spacingMM float64) model.LayoutPreview {
 	pw := plate.PrintableWidth()
 	ph := plate.PrintableHeight()
-	fw, fh := Footprint(spec)
-	cw, ch := CellPitch(spec, spacingMM)
+	itemW := spec.SizeMM
+	cw := itemW + spacingMM
+	ch := itemW + spacingMM
 
 	cols, rows := gridCount(pw, ph, cw, ch)
 	count := cols * rows
@@ -49,8 +38,8 @@ func Pack(plate model.Plate, spec model.ItemSpec, spacingMM float64) model.Layou
 		PrintableHMM:  ph,
 		CellWidthMM:   cw,
 		CellHeightMM:  ch,
-		FootprintWMM:  fw,
-		FootprintHMM:  fh,
+		FootprintWMM:  itemW,
+		FootprintHMM:  itemW,
 		SpacingMM:     spacingMM,
 		Columns:       cols,
 		Rows:          rows,

internal/layout/layout_test.go

@@ -16,20 +16,22 @@ func TestPack(t *testing.T) {
 		MarginLeft:   10,
 	}
 	spec := model.ItemSpec{SizeMM: 80, BleedMM: 2, MarginMM: 5}
-	// footprint = 80+4+10 = 94, cell = 94+2 = 96
-	// printable 280x380 -> cols=2, rows=3 -> 6
+	// viewport 80mm, cell = 80+2 = 82, printable 280x380 -> cols=3, rows=4 -> 12
 	preview := Pack(plate, spec, 2)
-	if preview.Columns != 2 {
-		t.Fatalf("columns: got %d want 2", preview.Columns)
+	if preview.Columns != 3 {
+		t.Fatalf("columns: got %d want 3", preview.Columns)
 	}
-	if preview.Rows != 3 {
-		t.Fatalf("rows: got %d want 3", preview.Rows)
+	if preview.Rows != 4 {
+		t.Fatalf("rows: got %d want 4", preview.Rows)
 	}
-	if preview.Count != 6 {
-		t.Fatalf("count: got %d want 6", preview.Count)
+	if preview.Count != 12 {
+		t.Fatalf("count: got %d want 12", preview.Count)
 	}
-	if len(preview.Positions) != 6 {
-		t.Fatalf("positions: got %d want 6", len(preview.Positions))
+	if preview.FootprintWMM != 80 {
+		t.Fatalf("footprint width: got %v want 80", preview.FootprintWMM)
+	}
+	if len(preview.Positions) != 12 {
+		t.Fatalf("positions: got %d want 12", len(preview.Positions))
 	}
 	if preview.Positions[0].XMM != 10 || preview.Positions[0].YMM != 10 {
 		t.Fatalf("first position: got (%v,%v)", preview.Positions[0].XMM, preview.Positions[0].YMM)