Moved default font methods into functions, added methods to gc to expose variables related to fonts
This commit is contained in:
redstarcoder
parent
ebcac18cbb
commit
8c94f068e3
5 changed files with 212 additions and 135 deletions
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@ -4,21 +4,13 @@
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package draw2dbase
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import (
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"errors"
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"image"
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"image/color"
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"log"
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"math"
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"github.com/llgcode/draw2d"
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"github.com/golang/freetype/truetype"
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"golang.org/x/image/font"
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"golang.org/x/image/math/fixed"
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)
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var DefaultFontData = draw2d.FontData{Name: "luxi", Family: draw2d.FontFamilySans, Style: draw2d.FontStyleNormal}
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type StackGraphicContext struct {
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Current *ContextStack
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}
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@ -41,8 +33,6 @@ type ContextStack struct {
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// fontSize and dpi are used to calculate scale. scale is the number of
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// 26.6 fixed point units in 1 em.
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Scale float64
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glyphBuf *truetype.GlyphBuf
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DPI int
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Previous *ContextStack
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}
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@ -63,8 +53,6 @@ func NewStackGraphicContext() *StackGraphicContext {
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gc.Current.Join = draw2d.RoundJoin
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gc.Current.FontSize = 10
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gc.Current.FontData = DefaultFontData
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gc.Current.glyphBuf = &truetype.GlyphBuf{}
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gc.Current.DPI = 92
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return gc
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}
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@ -121,16 +109,31 @@ func (gc *StackGraphicContext) SetLineDash(dash []float64, dashOffset float64) {
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gc.Current.DashOffset = dashOffset
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}
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// SetFontSize sets the font size in points (as in ``a 12 point font'').
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func (gc *StackGraphicContext) SetFontSize(fontSize float64) {
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gc.Current.FontSize = fontSize
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gc.recalc()
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}
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func (gc *StackGraphicContext) GetFontSize() float64 {
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return gc.Current.FontSize
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}
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func (gc *StackGraphicContext) SetScale(scale float64) {
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gc.Current.Scale = scale
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}
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func (gc *StackGraphicContext) GetScale() float64 {
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return gc.Current.Scale
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}
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// SetFont sets the font used to draw text
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func (gc *StackGraphicContext) SetFont(font *truetype.Font) {
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gc.Current.Font = font
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}
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func (gc *StackGraphicContext) GetFont() *truetype.Font {
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return gc.Current.Font
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}
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func (gc *StackGraphicContext) SetFontData(fontData draw2d.FontData) {
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gc.Current.FontData = fontData
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}
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@ -190,8 +193,6 @@ func (gc *StackGraphicContext) Save() {
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context.Path = gc.Current.Path.Copy()
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context.Font = gc.Current.Font
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context.Scale = gc.Current.Scale
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context.glyphBuf = gc.Current.glyphBuf
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context.DPI = gc.Current.DPI
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copy(context.Tr[:], gc.Current.Tr[:])
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context.Previous = gc.Current
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gc.Current = context
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@ -204,117 +205,3 @@ func (gc *StackGraphicContext) Restore() {
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oldContext.Previous = nil
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}
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}
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func (gc *StackGraphicContext) loadCurrentFont() (*truetype.Font, error) {
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font := draw2d.GetFont(gc.Current.FontData)
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if font == nil {
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font = draw2d.GetFont(DefaultFontData)
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}
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if font == nil {
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return nil, errors.New("No font set, and no default font available.")
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}
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gc.SetFont(font)
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gc.SetFontSize(gc.Current.FontSize)
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return font, nil
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}
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func (gc *StackGraphicContext) drawGlyph(glyph truetype.Index, dx, dy float64) error {
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if err := gc.Current.glyphBuf.Load(gc.Current.Font, fixed.Int26_6(gc.Current.Scale), glyph, font.HintingNone); err != nil {
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return err
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}
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e0 := 0
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for _, e1 := range gc.Current.glyphBuf.Ends {
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DrawContour(gc, gc.Current.glyphBuf.Points[e0:e1], dx, dy)
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e0 = e1
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}
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return nil
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}
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// CreateStringPath creates a path from the string s at x, y, and returns the string width.
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// The text is placed so that the left edge of the em square of the first character of s
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// and the baseline intersect at x, y. The majority of the affected pixels will be
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// above and to the right of the point, but some may be below or to the left.
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// For example, drawing a string that starts with a 'J' in an italic font may
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// affect pixels below and left of the point.
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func (gc *StackGraphicContext) CreateStringPath(s string, x, y float64) float64 {
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f, err := gc.loadCurrentFont()
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if err != nil {
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log.Println(err)
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return 0.0
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}
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startx := x
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prev, hasPrev := truetype.Index(0), false
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for _, rune := range s {
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index := f.Index(rune)
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if hasPrev {
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x += fUnitsToFloat64(f.Kern(fixed.Int26_6(gc.Current.Scale), prev, index))
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}
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err := gc.drawGlyph(index, x, y)
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if err != nil {
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log.Println(err)
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return startx - x
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}
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x += fUnitsToFloat64(f.HMetric(fixed.Int26_6(gc.Current.Scale), index).AdvanceWidth)
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prev, hasPrev = index, true
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}
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return x - startx
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}
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// GetStringBounds returns the approximate pixel bounds of the string s at x, y.
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// The the left edge of the em square of the first character of s
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// and the baseline intersect at 0, 0 in the returned coordinates.
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// Therefore the top and left coordinates may well be negative.
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func (gc *StackGraphicContext) GetStringBounds(s string) (left, top, right, bottom float64) {
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f, err := gc.loadCurrentFont()
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if err != nil {
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log.Println(err)
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return 0, 0, 0, 0
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}
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top, left, bottom, right = 10e6, 10e6, -10e6, -10e6
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cursor := 0.0
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prev, hasPrev := truetype.Index(0), false
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for _, rune := range s {
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index := f.Index(rune)
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if hasPrev {
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cursor += fUnitsToFloat64(f.Kern(fixed.Int26_6(gc.Current.Scale), prev, index))
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}
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if err := gc.Current.glyphBuf.Load(gc.Current.Font, fixed.Int26_6(gc.Current.Scale), index, font.HintingNone); err != nil {
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log.Println(err)
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return 0, 0, 0, 0
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}
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e0 := 0
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for _, e1 := range gc.Current.glyphBuf.Ends {
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ps := gc.Current.glyphBuf.Points[e0:e1]
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for _, p := range ps {
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x, y := pointToF64Point(p)
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top = math.Min(top, y)
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bottom = math.Max(bottom, y)
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left = math.Min(left, x+cursor)
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right = math.Max(right, x+cursor)
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}
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}
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cursor += fUnitsToFloat64(f.HMetric(fixed.Int26_6(gc.Current.Scale), index).AdvanceWidth)
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prev, hasPrev = index, true
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}
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return left, top, right, bottom
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}
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// recalc recalculates scale and bounds values from the font size, screen
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// resolution and font metrics, and invalidates the glyph cache.
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func (gc *StackGraphicContext) recalc() {
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gc.Current.Scale = gc.Current.FontSize * float64(gc.Current.DPI) * (64.0 / 72.0)
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}
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func (gc *StackGraphicContext) SetDPI(dpi int) {
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gc.Current.DPI = dpi
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gc.recalc()
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}
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// SetFont sets the font used to draw text.
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func (gc *StackGraphicContext) SetFont(font *truetype.Font) {
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gc.Current.Font = font
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}
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func (gc *StackGraphicContext) GetDPI() int {
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return gc.Current.DPI
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}
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@ -1,12 +1,127 @@
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package draw2dbase
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import (
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"errors"
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"log"
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"math"
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"github.com/golang/freetype/truetype"
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"github.com/llgcode/draw2d"
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"golang.org/x/image/font"
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"golang.org/x/image/math/fixed"
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)
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var (
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glyphBuf = &truetype.GlyphBuf{}
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DefaultFontData = draw2d.FontData{Name: "luxi", Family: draw2d.FontFamilySans, Style: draw2d.FontStyleNormal}
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)
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func loadCurrentFont(gc draw2d.GraphicContext) (*truetype.Font, error) {
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font := draw2d.GetFont(gc.GetFontData())
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if font == nil {
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font = draw2d.GetFont(DefaultFontData)
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}
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if font == nil {
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return nil, errors.New("No font set, and no default font available.")
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}
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gc.SetFont(font)
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gc.SetFontSize(gc.GetFontSize())
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recalc(gc)
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return font, nil
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}
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func drawGlyph(gc draw2d.GraphicContext, glyph truetype.Index, dx, dy float64) error {
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if err := glyphBuf.Load(gc.GetFont(), fixed.Int26_6(gc.GetScale()), glyph, font.HintingNone); err != nil {
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return err
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}
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e0 := 0
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for _, e1 := range glyphBuf.Ends {
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DrawContour(gc, glyphBuf.Points[e0:e1], dx, dy)
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e0 = e1
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}
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return nil
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}
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// CreateStringPath creates a path from the string s at x, y, and returns the string width.
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// The text is placed so that the left edge of the em square of the first character of s
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// and the baseline intersect at x, y. The majority of the affected pixels will be
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// above and to the right of the point, but some may be below or to the left.
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// For example, drawing a string that starts with a 'J' in an italic font may
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// affect pixels below and left of the point.
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func CreateStringPath(gc draw2d.GraphicContext, s string, x, y float64) float64 {
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f, err := loadCurrentFont(gc)
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if err != nil {
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log.Println(err)
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return 0.0
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}
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startx := x
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prev, hasPrev := truetype.Index(0), false
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scale := gc.GetScale()
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for _, rune := range s {
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index := f.Index(rune)
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if hasPrev {
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x += fUnitsToFloat64(f.Kern(fixed.Int26_6(scale), prev, index))
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}
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err := drawGlyph(gc, index, x, y)
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if err != nil {
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log.Println(err)
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return startx - x
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}
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x += fUnitsToFloat64(f.HMetric(fixed.Int26_6(scale), index).AdvanceWidth)
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prev, hasPrev = index, true
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}
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return x - startx
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}
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// GetStringBounds returns the approximate pixel bounds of the string s at x, y.
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// The the left edge of the em square of the first character of s
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// and the baseline intersect at 0, 0 in the returned coordinates.
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// Therefore the top and left coordinates may well be negative.
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func GetStringBounds(gc draw2d.GraphicContext, s string) (left, top, right, bottom float64) {
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f, err := loadCurrentFont(gc)
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if err != nil {
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log.Println(err)
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return 0, 0, 0, 0
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}
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top, left, bottom, right = 10e6, 10e6, -10e6, -10e6
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cursor := 0.0
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prev, hasPrev := truetype.Index(0), false
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scale := gc.GetScale()
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for _, rune := range s {
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index := f.Index(rune)
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if hasPrev {
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cursor += fUnitsToFloat64(f.Kern(fixed.Int26_6(scale), prev, index))
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}
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if err := glyphBuf.Load(gc.GetFont(), fixed.Int26_6(scale), index, font.HintingNone); err != nil {
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log.Println(err)
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return 0, 0, 0, 0
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}
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e0 := 0
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for _, e1 := range glyphBuf.Ends {
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ps := glyphBuf.Points[e0:e1]
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for _, p := range ps {
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x, y := pointToF64Point(p)
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top = math.Min(top, y)
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bottom = math.Max(bottom, y)
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left = math.Min(left, x+cursor)
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right = math.Max(right, x+cursor)
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}
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}
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cursor += fUnitsToFloat64(f.HMetric(fixed.Int26_6(gc.GetScale()), index).AdvanceWidth)
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prev, hasPrev = index, true
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}
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return left, top, right, bottom
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}
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// recalc recalculates scale and bounds values from the font size, screen
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// resolution and font metrics, and invalidates the glyph cache.
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func recalc(gc draw2d.GraphicContext) {
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gc.SetScale(gc.GetFontSize() * float64(gc.GetDPI()) * (64.0 / 72.0))
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}
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// DrawContour draws the given closed contour at the given sub-pixel offset.
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func DrawContour(path draw2d.PathBuilder, ps []truetype.Point, dx, dy float64) {
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if len(ps) == 0 {
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@ -118,6 +118,7 @@ type GraphicContext struct {
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painter *Painter
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fillRasterizer *raster.Rasterizer
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strokeRasterizer *raster.Rasterizer
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DPI int
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}
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// NewGraphicContext creates a new Graphic context from an image.
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@ -127,10 +128,33 @@ func NewGraphicContext(width, height int) *GraphicContext {
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NewPainter(),
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raster.NewRasterizer(width, height),
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raster.NewRasterizer(width, height),
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92,
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}
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return gc
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}
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// CreateStringPath creates a path from the string s at x, y, and returns the string width.
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// The text is placed so that the left edge of the em square of the first character of s
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// and the baseline intersect at x, y. The majority of the affected pixels will be
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// above and to the right of the point, but some may be below or to the left.
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// For example, drawing a string that starts with a 'J' in an italic font may
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// affect pixels below and left of the point.
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func (gc *GraphicContext) CreateStringPath(s string, x, y float64) float64 {
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return draw2dbase.CreateStringPath(gc, s, x, y)
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}
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// GetStringBounds returns the approximate pixel bounds of the string s at x, y.
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// The the left edge of the em square of the first character of s
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// and the baseline intersect at 0, 0 in the returned coordinates.
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// Therefore the top and left coordinates may well be negative.
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func (gc *GraphicContext) GetStringBounds(s string) (left, top, right, bottom float64) {
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return draw2dbase.GetStringBounds(gc, s)
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}
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func (gc *GraphicContext) FillString(text string) (cursor float64) {
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return gc.FillStringAt(text, 0, 0)
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}
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func (gc *GraphicContext) FillStringAt(text string, x, y float64) (width float64) {
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width = gc.CreateStringPath(text, x, y)
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gc.Fill()
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@ -147,6 +171,19 @@ func (gc *GraphicContext) StrokeStringAt(text string, x, y float64) (width float
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return width
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}
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func (gc *GraphicContext) SetDPI(dpi int) {
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gc.DPI = dpi
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}
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func (gc *GraphicContext) GetDPI() int {
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return gc.DPI
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}
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// SetFontSize sets the font size in points (as in ``a 12 point font'').
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func (gc *GraphicContext) SetFontSize(fontSize float64) {
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gc.Current.FontSize = fontSize
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}
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//TODO
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func (gc *GraphicContext) Clear() {
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panic("not implemented")
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@ -162,10 +199,6 @@ func (gc *GraphicContext) DrawImage(img image.Image) {
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panic("not implemented")
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}
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func (gc *GraphicContext) FillString(text string) (cursor float64) {
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return gc.FillStringAt(text, 0, 0)
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}
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func (gc *GraphicContext) paint(rasterizer *raster.Rasterizer, color color.Color) {
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gc.painter.SetColor(color)
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rasterizer.Rasterize(gc.painter)
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@ -28,6 +28,7 @@ type GraphicContext struct {
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painter Painter
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fillRasterizer *raster.Rasterizer
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strokeRasterizer *raster.Rasterizer
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DPI int
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}
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// ImageFilter defines the type of filter to use
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@ -44,7 +45,6 @@ const (
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// NewGraphicContext creates a new Graphic context from an image.
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func NewGraphicContext(img draw.Image) *GraphicContext {
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var painter Painter
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switch selectImage := img.(type) {
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case *image.RGBA:
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@ -57,6 +57,7 @@ func NewGraphicContext(img draw.Image) *GraphicContext {
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// NewGraphicContextWithPainter creates a new Graphic context from an image and a Painter (see Freetype-go)
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func NewGraphicContextWithPainter(img draw.Image, painter Painter) *GraphicContext {
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dpi := 92
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width, height := img.Bounds().Dx(), img.Bounds().Dy()
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gc := &GraphicContext{
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draw2dbase.NewStackGraphicContext(),
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@ -64,6 +65,7 @@ func NewGraphicContextWithPainter(img draw.Image, painter Painter) *GraphicConte
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painter,
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raster.NewRasterizer(width, height),
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raster.NewRasterizer(width, height),
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dpi,
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}
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return gc
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}
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@ -99,6 +101,24 @@ func (gc *GraphicContext) DrawImage(img image.Image) {
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DrawImage(img, gc.img, gc.Current.Tr, draw.Over, BilinearFilter)
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}
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||||
|
||||
// CreateStringPath creates a path from the string s at x, y, and returns the string width.
|
||||
// The text is placed so that the left edge of the em square of the first character of s
|
||||
// and the baseline intersect at x, y. The majority of the affected pixels will be
|
||||
// above and to the right of the point, but some may be below or to the left.
|
||||
// For example, drawing a string that starts with a 'J' in an italic font may
|
||||
// affect pixels below and left of the point.
|
||||
func (gc *GraphicContext) CreateStringPath(s string, x, y float64) float64 {
|
||||
return draw2dbase.CreateStringPath(gc, s, x, y)
|
||||
}
|
||||
|
||||
// GetStringBounds returns the approximate pixel bounds of the string s at x, y.
|
||||
// The the left edge of the em square of the first character of s
|
||||
// and the baseline intersect at 0, 0 in the returned coordinates.
|
||||
// Therefore the top and left coordinates may well be negative.
|
||||
func (gc *GraphicContext) GetStringBounds(s string) (left, top, right, bottom float64) {
|
||||
return draw2dbase.GetStringBounds(gc, s)
|
||||
}
|
||||
|
||||
// FillString draws the text at point (0, 0)
|
||||
func (gc *GraphicContext) FillString(text string) (cursor float64) {
|
||||
return gc.FillStringAt(text, 0, 0)
|
||||
|
|
@ -123,6 +143,19 @@ func (gc *GraphicContext) StrokeStringAt(text string, x, y float64) (cursor floa
|
|||
return width
|
||||
}
|
||||
|
||||
func (gc *GraphicContext) SetDPI(dpi int) {
|
||||
gc.DPI = dpi
|
||||
}
|
||||
|
||||
func (gc *GraphicContext) GetDPI() int {
|
||||
return gc.DPI
|
||||
}
|
||||
|
||||
// SetFontSize sets the font size in points (as in ``a 12 point font'').
|
||||
func (gc *GraphicContext) SetFontSize(fontSize float64) {
|
||||
gc.Current.FontSize = fontSize
|
||||
}
|
||||
|
||||
func (gc *GraphicContext) paint(rasterizer *raster.Rasterizer, color color.Color) {
|
||||
gc.painter.SetColor(color)
|
||||
rasterizer.Rasterize(gc.painter)
|
||||
|
|
|
|||
9
gc.go
9
gc.go
|
|
@ -6,6 +6,7 @@ package draw2d
|
|||
import (
|
||||
"image"
|
||||
"image/color"
|
||||
"github.com/golang/freetype/truetype"
|
||||
)
|
||||
|
||||
// GraphicContext describes the interface for the various backends (images, pdf, opengl, ...)
|
||||
|
|
@ -44,6 +45,14 @@ type GraphicContext interface {
|
|||
SetFontSize(fontSize float64)
|
||||
// GetFontSize gets the current font size
|
||||
GetFontSize() float64
|
||||
// SetScale sets the current font scale
|
||||
SetScale(scale float64)
|
||||
// GetScale gets the current font scale
|
||||
GetScale() float64
|
||||
// SetFont sets the current truetype.Font
|
||||
SetFont(font *truetype.Font)
|
||||
// GetFont gets the current truetype.Font
|
||||
GetFont() *truetype.Font
|
||||
// SetFontData sets the current FontData
|
||||
SetFontData(fontData FontData)
|
||||
// GetFontData gets the current FontData
|
||||
|
|
|
|||
Loading…
Reference in a new issue