properties.go: Add a 'LayerZ()' function to get the (rounded) layer h…

…eight

Summary:
- Fixes #85

cws/format.go

@@ -517,7 +517,7 @@ func (cws *CWS) Layer(index int) (layer uv3dp.Layer) {
 		panic(err)
 	}
 
-	layer.Z = float32(index) * cws.properties.Size.LayerHeight
+	layer.Z = cws.properties.LayerZ(index)
 	layer.Image = pngImage.(*image.Gray)
 	layer.Exposure = cws.properties.LayerExposure(index)
 

empty.go

@@ -29,7 +29,7 @@ func (empty *EmptyPrintable) Properties() (prop Properties) {
 func (empty *EmptyPrintable) Layer(index int) (layer Layer) {
 	prop := empty.Properties()
 
-	layer.Z = prop.Size.LayerHeight * float32(index)
+	layer.Z = prop.LayerZ(index)
 	layer.Image = image.NewGray(prop.Bounds())
 
 	if index < prop.Bottom.Count {

properties.go

@@ -6,6 +6,7 @@ package uv3dp
 
 import (
 	"image"
+	"math"
 )
 
 type SizeMillimeter struct {
@@ -118,3 +119,8 @@ func (prop *Properties) LayerExposure(index int) (exposure Exposure) {
 
 	return
 }
+
+// LayerZ get the default Z height at a layer index
+func (prop *Properties) LayerZ(index int) (z float32) {
+	return float32(math.Round(float64(prop.Size.LayerHeight)*float64(index+1)*100) / 100.0)
+}

pws/format.go

@@ -589,7 +589,7 @@ func (pws *Print) Layer(index int) (layer uv3dp.Layer) {
 		panic(fmt.Sprintf("pws: layer %v/%v: %s", index+1, prop.Size.Layers, err))
 	}
 
-	layer.Z = float32(index) * prop.Size.LayerHeight
+	layer.Z = prop.LayerZ(index)
 	layer.Image = slice
 	return
 }

sl1/format.go

@@ -409,7 +409,7 @@ func (sl1 *Sl1) Layer(index int) (layer uv3dp.Layer) {
 		panic(err)
 	}
 
-	layer.Z = float32(index) * sl1.properties.Size.LayerHeight
+	layer.Z = sl1.properties.LayerZ(index)
 	layer.Image = pngImage.(*image.Gray)
 	layer.Exposure = sl1.properties.LayerExposure(index)
 

uvj/format.go

@@ -287,7 +287,7 @@ func (uvj *UVJ) Layer(index int) (layer uv3dp.Layer) {
 
 	if len(uvj.Config.Layers) == 0 {
 		layer = uv3dp.Layer{
-			Z:        float32(index) * uvj.Config.Properties.Size.LayerHeight,
+			Z:        uvj.Config.Properties.LayerZ(index),
 			Exposure: uvj.Config.Properties.LayerExposure(index),
 		}
 	} else {

uvj/format_test.go

@@ -108,7 +108,7 @@ const (
   },
   "Layers": [
     {
-      "Z": 0,
+      "Z": 0.05,
       "Exposure": {
         "LightOnTime": 30.5,
         "LightOffTime": 2.25,
@@ -119,7 +119,7 @@ const (
       }
     },
     {
-      "Z": 0.05,
+      "Z": 0.1,
       "Exposure": {
         "LightOnTime": 30.5,
         "LightOffTime": 2.25,
@@ -130,7 +130,7 @@ const (
       }
     },
     {
-      "Z": 0.1,
+      "Z": 0.15,
       "Exposure": {
         "LightOnTime": 16.5,
         "LightOffTime": 2.25,
@@ -142,7 +142,7 @@ const (
       }
     },
     {
-      "Z": 0.15,
+      "Z": 0.2,
       "Exposure": {
         "LightOnTime": 16.5,
         "LightOffTime": 2.25,

zcodex/format.go

@@ -418,7 +418,7 @@ func (zcodex *Zcodex) Layer(index int) (layer uv3dp.Layer) {
 		grayImage = asGray(pngImage)
 	}
 
-	layer.Z = float32(index) * zcodex.properties.Size.LayerHeight
+	layer.Z = zcodex.properties.LayerZ(index)
 	layer.Image = grayImage
 	layer.Exposure = zcodex.properties.LayerExposure(index)