Text rendering is a thing again

artist/pattern.go

@@ -0,0 +1,12 @@
+package artist
+
+import "image/color"
+
+// Pattern is capable of generating a pattern pixel by pixel.
+type Pattern interface {
+	// AtWhen returns the color of the pixel located at (x, y) relative to
+	// the origin point of the pattern (0, 0), when the pattern has the
+	// specified width and height. Patterns may ignore the width and height
+	// parameters, but it may be useful for some patterns such as gradients.
+	AtWhen (x, y, width, height int) (color.RGBA)
+}

artist/rectangle.go

@@ -29,6 +29,7 @@ func Paste (
 	return
 }
 
+// FillRectangle draws a filled rectangle with the specified pattern.
 func FillRectangle (
 	destination tomo.Canvas,
 	source Pattern,

artist/text.go

@@ -3,7 +3,7 @@ package artist
 // import "fmt"
 import "image"
 import "unicode"
-// import "image/draw"
+import "image/draw"
 import "golang.org/x/image/font"
 import "golang.org/x/image/math/fixed"
 import "git.tebibyte.media/sashakoshka/tomo"
@@ -100,30 +100,36 @@ func (drawer *TextDrawer) Draw (
 ) (
 	updatedRegion image.Rectangle,
 ) {
+	wrappedSource := WrappedPattern {
+		Pattern: source,
+		Width:  0,
+		Height: 0, // TODO: choose a better width and height
+	}
+
 	if !drawer.layoutClean { drawer.recalculate() }
 	// TODO: reimplement a version of draw mask that takes in a pattern
-	// for _, word := range drawer.layout {
-	// for _, character := range word.text {
-		// destinationRectangle,
-		// mask, maskPoint, _, ok := drawer.face.Glyph (
-			// fixed.P (
-				// offset.X + word.position.X + character.x,
-				// offset.Y + word.position.Y),
-			// character.character)
-		// if !ok { continue }
+	for _, word := range drawer.layout {
+	for _, character := range word.text {
+		destinationRectangle,
+		mask, maskPoint, _, ok := drawer.face.Glyph (
+			fixed.P (
+				offset.X + word.position.X + character.x,
+				offset.Y + word.position.Y),
+			character.character)
+		if !ok { continue }
 
 		// FIXME: clip destination rectangle if we are on the cusp of
 		// the maximum height.
 
-		// draw.DrawMask (
-			// destination,
-			// destinationRectangle,
-			// source, image.Point { },
-			// mask, maskPoint,
-			// draw.Over)
+		draw.DrawMask (
+			destination,
+			destinationRectangle,
+			wrappedSource, image.Point { },
+			mask, maskPoint,
+			draw.Over)
 
-		// updatedRegion = updatedRegion.Union(destinationRectangle)
-	// }}
+		updatedRegion = updatedRegion.Union(destinationRectangle)
+	}}
 	return
 }
 

artist/texture.go

@@ -3,15 +3,6 @@ package artist
 import "image"
 import "image/color"
 
-// Pattern is capable of generating a pattern pixel by pixel.
-type Pattern interface {
-	// AtWhen returns the color of the pixel located at (x, y) relative to
-	// the origin point of the pattern (0, 0), when the pattern has the
-	// specified width and height. Patterns may ignore the width and height
-	// parameters, but it may be useful for some patterns such as gradients.
-	AtWhen (x, y, width, height int) (color.RGBA)
-}
-
 // Texture is a struct that allows an image to be converted into a tiling
 // texture pattern.
 type Texture struct {

artist/uniform.go

@@ -4,61 +4,52 @@ import "image"
 import "image/color"
 
 // Uniform is an infinite-sized pattern of uniform color. It implements the
-// color.Color, color.Model, and image.Image interfaces.
-type Uniform struct {
-	C color.RGBA
-}
+// Pattern, color.Color, color.Model, and image.Image interfaces.
+type Uniform color.RGBA
 
 // NewUniform returns a new Uniform image of the given color.
-func NewUniform (c color.Color) (uniform *Uniform) {
-	uniform = &Uniform { }
+func NewUniform (c color.Color) (uniform Uniform) {
 	r, g, b, a := c.RGBA()
-	uniform.C.R = uint8(r >> 8)
-	uniform.C.G = uint8(g >> 8)
-	uniform.C.B = uint8(b >> 8)
-	uniform.C.A = uint8(a >> 8)
+	uniform.R = uint8(r >> 8)
+	uniform.G = uint8(g >> 8)
+	uniform.B = uint8(b >> 8)
+	uniform.A = uint8(a >> 8)
 	return
 }
 
-func (uniform *Uniform) RGBA () (r, g, b, a uint32) {
-	r = uint32(uniform.C.R) << 8 | uint32(uniform.C.R)
-	g = uint32(uniform.C.G) << 8 | uint32(uniform.C.G)
-	b = uint32(uniform.C.B) << 8 | uint32(uniform.C.B)
-	a = uint32(uniform.C.A) << 8 | uint32(uniform.C.A)
-	return
-}
-
-func (uniform *Uniform) ColorModel () (model color.Model) {
+// ColorModel satisfies the image.Image interface.
+func (uniform Uniform) ColorModel () (model color.Model) {
 	return uniform
 }
 
-func (uniform *Uniform) Convert (in color.Color) (c color.Color) {
-	return uniform.C
+// Convert satisfies the color.Model interface.
+func (uniform Uniform) Convert (in color.Color) (c color.Color) {
+	return color.RGBA(uniform)
 }
 
-func (uniform *Uniform) Bounds () (rectangle image.Rectangle) {
+// Bounds satisfies the image.Image interface.
+func (uniform Uniform) Bounds () (rectangle image.Rectangle) {
 	rectangle.Min = image.Point { -1e9, -1e9 }
 	rectangle.Max = image.Point {  1e9,  1e9 }
 	return
 }
 
-func (uniform *Uniform) At (x, y int) (c color.Color) {
-	return uniform.C
+// At satisfies the image.Image interface.
+func (uniform Uniform) At (x, y int) (c color.Color) {
+	return color.RGBA(uniform)
 }
 
-func (uniform *Uniform) AtWhen (x, y, width, height int) (c color.RGBA) {
-	return uniform.C
+// AtWhen satisfies the Pattern interface.
+func (uniform Uniform) AtWhen (x, y, width, height int) (c color.RGBA) {
+	return color.RGBA(uniform)
 }
 
-func (uniform *Uniform) RGBA64At (x, y int) (c color.RGBA64) {
-	r := uint16(uniform.C.R) << 8 | uint16(uniform.C.R)
-	g := uint16(uniform.C.G) << 8 | uint16(uniform.C.G)
-	b := uint16(uniform.C.B) << 8 | uint16(uniform.C.B)
-	a := uint16(uniform.C.A) << 8 | uint16(uniform.C.A)
-	return color.RGBA64 { R: r, G: g, B: b, A: a }
+// RGBA satisfies the color.Color interface.
+func (uniform Uniform) RGBA () (r, g, b, a uint32) {
+	return color.RGBA(uniform).RGBA()
 }
 
 // Opaque scans the entire image and reports whether it is fully opaque.
-func (uniform *Uniform) Opaque () (opaque bool) {
-	return uniform.C.A == 0xFF
+func (uniform Uniform) Opaque () (opaque bool) {
+	return uniform.A == 0xFF
 }

artist/wrap.go

@@ -1 +1,27 @@
 package artist
+
+import "image"
+import "image/color"
+
+// WrappedPattern is a pattern that is able to behave like an image.Image.
+type WrappedPattern struct {
+	Pattern
+	Width, Height int
+}
+
+// At satisfies the image.Image interface.
+func (pattern WrappedPattern) At (x, y int) (c color.Color) {
+	return pattern.Pattern.AtWhen(x, y, pattern.Width, pattern.Height)
+}
+
+// Bounds satisfies the image.Image interface.
+func (pattern WrappedPattern) Bounds () (rectangle image.Rectangle) {
+	rectangle.Min = image.Point { -1e9, -1e9 }
+	rectangle.Max = image.Point {  1e9,  1e9 }
+	return
+}
+
+// ColorModel satisfies the image.Image interface.
+func (pattern WrappedPattern) ColorModel () (model color.Model) {
+	return color.RGBAModel
+}