66 lines
1.7 KiB
Go
66 lines
1.7 KiB
Go
package typeset
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import "image"
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import "unicode"
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import "image/draw"
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import "image/color"
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import "golang.org/x/image/font"
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import "golang.org/x/image/math/fixed"
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import "git.tebibyte.media/tomo/typeset/internal"
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// Draw draws the contents of a TypeSetter to an image at the given offset. It
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// returns a rectangle containing all pixels in the image that were updated.
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func Draw (destination draw.Image, setter *TypeSetter, offset fixed.Point26_6, col color.Color) image.Rectangle {
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source := image.NewUniform(col)
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face := setter.Face()
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var updatedRegion image.Rectangle
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bounds := destination.Bounds()
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setter.Runes()(func (position fixed.Point26_6, run rune) bool {
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// leave empty space for space characters
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if unicode.IsSpace(run) {
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return true
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}
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dot := offset.Add(position)
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destinationRectangle, mask, maskPoint, _, ok := face.Glyph(dot, run)
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if ok {
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// don't bother drawing runes that are out of bounds
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if destinationRectangle.Min.Y > bounds.Max.Y { return false }
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if destinationRectangle.Intersect(bounds).Empty() { return true }
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// draw rune
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draw.DrawMask (
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destination,
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destinationRectangle,
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source, image.Point { },
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mask, maskPoint,
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draw.Over)
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} else {
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// draw tofu
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drawTofu(run, destination, dot, face, col)
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}
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updatedRegion = updatedRegion.Union(destinationRectangle)
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return true
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})
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return updatedRegion
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}
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func drawTofu (
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char rune,
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destination draw.Image,
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position fixed.Point26_6,
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face font.Face,
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col color.Color,
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) {
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bounds, _ := tofuBounds(face)
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rectBounds := internal.RoundRect(bounds).Add(image.Pt (
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position.X.Round(),
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position.Y.Round()))
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internal.DrawRectangleOutline(destination, rectBounds, col)
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}
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