Comments and move stuff around

glyphs/font_atlas.go

@@ -20,6 +20,7 @@ type FontAtlas struct {
 	Font *truetype.Font
 	Face font.Face
 	Img  *image.RGBA
+	// A map version of nset (https://github.com/bloeys/nset) would be amazing here
 	Glyphs map[rune]FontAtlasGlyph
 
 	//SpaceAdvance is the advance of a space char
@@ -63,73 +64,7 @@ func NewFontAtlasFromFile(fontFile string, fontOptions *truetype.Options) (*Font
 	return NewFontAtlasFromFont(f, face, uint(fontOptions.Size))
 }
 
-func calcNeededAtlasSize(glyphs []rune, face font.Face, charPaddingXFixed, charPaddingYFixed fixed.Int26_6) (atlasSizeX, atlasSizeY int) {
+// NewFontAtlasFromFont uses the passed font to produce a font texture atlas containing
-
-	//Calculate needed atlas size
-	atlasSizeX = 512
-	atlasSizeY = 512
-	largestLineDescent := fixed.I(0)
-	spaceAdv, _ := face.GlyphAdvance(' ')
-	lineHeight := face.Metrics().Height
-	foundAtlasSize := false
-	for !foundAtlasSize {
-
-		foundAtlasSize = true
-		dotX := spaceAdv + charPaddingXFixed
-		dotY := lineHeight
-		atlasSizeXFixed := fixed.I(atlasSizeX)
-		atlasSizeYFixed := fixed.I(atlasSizeY)
-		for i := 0; i < len(glyphs); i++ {
-
-			//Prepare all glyph metrics
-			g := glyphs[i]
-			gBounds, _, _ := face.GlyphBounds(g)
-			bearingXFixed := gBounds.Min.X
-			gWidthFixed := gBounds.Max.X - gBounds.Min.X
-			descentAbsFixed := absI26_6(gBounds.Max.Y)
-
-			if descentAbsFixed > largestLineDescent {
-				largestLineDescent = descentAbsFixed
-			}
-
-			//If bearing is negative this char might overlap with the previous one.
-			//So we need to move the dot so the drawer won't overlap even after a negative offset
-			if bearingXFixed < 0 {
-				dotX += absI26_6(bearingXFixed)
-			}
-
-			// Calculate distance dot will move after drawing. Advance normally if line has space,
-			// otherwise go to next line and reset X position.
-			distToMoveX := bearingXFixed + gWidthFixed + charPaddingXFixed
-
-			//If we have no more space go to next line
-			if dotX+distToMoveX >= atlasSizeXFixed {
-
-				dotX = charPaddingXFixed
-				if bearingXFixed < 0 {
-					dotX += absI26_6(bearingXFixed)
-				}
-
-				dotY += lineHeight + fixed.I(largestLineDescent.Ceil()) + charPaddingYFixed
-				largestLineDescent = 0
-
-				//If we have only one more empty line then resize to be safe against descents being clipped
-				if dotY+lineHeight+charPaddingYFixed >= atlasSizeYFixed {
-					atlasSizeX *= 2
-					atlasSizeY *= 2
-					foundAtlasSize = false
-					break
-				}
-			}
-
-			dotX += distToMoveX
-		}
-	}
-
-	return atlasSizeX, atlasSizeY
-}
-
-// NewFontAtlasFromFile uses the passed font to produce a font texture atlas containing
 // all its characters using the specified options. The atlas uses equally sized tiles
 // such that all characters use an equal horizontal/vertical on the atlas.
 // If the character is smaller than the tile then the rest of the tile is empty.
@@ -277,6 +212,72 @@ func NewFontAtlasFromFont(f *truetype.Font, face font.Face, pointSize uint) (*Fo
 	return atlas, nil
 }
 
+func calcNeededAtlasSize(glyphs []rune, face font.Face, charPaddingXFixed, charPaddingYFixed fixed.Int26_6) (atlasSizeX, atlasSizeY int) {
+
+	//Calculate needed atlas size
+	atlasSizeX = 512
+	atlasSizeY = 512
+	largestLineDescent := fixed.I(0)
+	spaceAdv, _ := face.GlyphAdvance(' ')
+	lineHeight := face.Metrics().Height
+	foundAtlasSize := false
+	for !foundAtlasSize {
+
+		foundAtlasSize = true
+		dotX := spaceAdv + charPaddingXFixed
+		dotY := lineHeight
+		atlasSizeXFixed := fixed.I(atlasSizeX)
+		atlasSizeYFixed := fixed.I(atlasSizeY)
+		for i := 0; i < len(glyphs); i++ {
+
+			//Prepare all glyph metrics
+			g := glyphs[i]
+			gBounds, _, _ := face.GlyphBounds(g)
+			bearingXFixed := gBounds.Min.X
+			gWidthFixed := gBounds.Max.X - gBounds.Min.X
+			descentAbsFixed := absI26_6(gBounds.Max.Y)
+
+			if descentAbsFixed > largestLineDescent {
+				largestLineDescent = descentAbsFixed
+			}
+
+			//If bearing is negative this char might overlap with the previous one.
+			//So we need to move the dot so the drawer won't overlap even after a negative offset
+			if bearingXFixed < 0 {
+				dotX += absI26_6(bearingXFixed)
+			}
+
+			// Calculate distance dot will move after drawing. Advance normally if line has space,
+			// otherwise go to next line and reset X position.
+			distToMoveX := bearingXFixed + gWidthFixed + charPaddingXFixed
+
+			//If we have no more space go to next line
+			if dotX+distToMoveX >= atlasSizeXFixed {
+
+				dotX = charPaddingXFixed
+				if bearingXFixed < 0 {
+					dotX += absI26_6(bearingXFixed)
+				}
+
+				dotY += lineHeight + fixed.I(largestLineDescent.Ceil()) + charPaddingYFixed
+				largestLineDescent = 0
+
+				//If we have only one more empty line then resize to be safe against descents being clipped
+				if dotY+lineHeight+charPaddingYFixed >= atlasSizeYFixed {
+					atlasSizeX *= 2
+					atlasSizeY *= 2
+					foundAtlasSize = false
+					break
+				}
+			}
+
+			dotX += distToMoveX
+		}
+	}
+
+	return atlasSizeX, atlasSizeY
+}
+
 func drawRectOutline(img *image.RGBA, rect image.Rectangle, color color.NRGBA) {
 
 	rowPixCount := img.Stride / 4

main.go

@@ -132,8 +132,6 @@ var (
 )
 
 // @TODO: Convert most operations to use glyphGrid instead of drawing directly to glyphRend
-// @TODO: Implement SDF glyph rendering
-
 func main() {
 
 	err := engine.Init()