diff options
| -rw-r--r-- | .hgignore | 1 | ||||
| -rw-r--r-- | def.go | 8 | ||||
| -rw-r--r-- | doc.go | 9 | ||||
| -rw-r--r-- | fpdf.go | 136 | ||||
| -rw-r--r-- | fpdf_test.go | 19 |
5 files changed, 161 insertions, 12 deletions
@@ -2,3 +2,4 @@ syntax: glob makefont/makefont pdf/*.pdf look +open @@ -29,6 +29,13 @@ type blendModeType struct { objNum int } +type gradientType struct { + tp int // 2: linear, 3: radial + clr1Str, clr2Str string + x1, y1, x2, y2, r float64 + objNum int +} + type sizeType struct { wd, ht float64 } @@ -129,6 +136,7 @@ type Fpdf struct { joinStyle int // line segment join style: miter 0, round 1, bevel 2 blendList []blendModeType // slice[idx] of alpha transparency modes, 1-based blendMap map[string]int // map into blendList + gradientList []gradientType // slice[idx] of gradient records err error // Set if error occurs during life cycle of instance } @@ -21,7 +21,8 @@ This package's code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF -transparency script by Martin Hall-May +transparency script by Martin Hall-May. Support for gradients is adapted from +the FPDF gradients script by Andreas Würmser. The FPDF website is http://www.fpdf.org/. @@ -37,9 +38,9 @@ Features • Image support (JPEG, PNG and GIF) -• Colors and alpha channel transparency +• Colors, gradients and alpha channel transparency -• Links +• Internal and external links • TrueType, Type1 and encoding support @@ -50,7 +51,7 @@ Features gofpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. Like FPDF version 1.7, from which gofpdf is derived, this package does not yet support UTF-8 source text. gofpdf is -released under the MIT License. +copyrighted by Kurt Jung and is released under the MIT License. Installation @@ -176,8 +176,10 @@ func New(orientationStr, unitStr, sizeStr, fontDirStr string) (f *Fpdf) { // Enable compression f.SetCompression(true) f.blendList = make([]blendModeType, 0, 8) - f.blendList = append(f.blendList, blendModeType{}) //blendMode[0] is unused (1-based) + f.blendList = append(f.blendList, blendModeType{}) // blendList[0] is unused (1-based) f.blendMap = make(map[string]int) + f.gradientList = make([]gradientType, 0, 8) + f.gradientList = append(f.gradientList, gradientType{}) // gradientList[0] is unused // Set default PDF version number f.pdfVersion = "1.3" return @@ -553,10 +555,24 @@ type clrType struct { r, g, b float64 } +func colorComp(v int) float64 { + if v < 0 { + v = 0 + } else if v > 255 { + v = 255 + } + return float64(v) / 255.0 +} + +func colorValueString(r, g, b int) string { + clr := colorValue(r, g, b) + return sprintf("%.3f %.3f %.3f", clr.r, clr.g, clr.b) +} + func colorValue(r, g, b int) (clr clrType) { - clr.r = float64(r) / 255.0 - clr.g = float64(g) / 255.0 - clr.b = float64(b) / 255.0 + clr.r = colorComp(r) + clr.g = colorComp(g) + clr.b = colorComp(b) return } @@ -857,6 +873,73 @@ func (f *Fpdf) SetAlpha(alpha float64, blendModeStr string) { f.outf("/GS%d gs", pos) } +func (f *Fpdf) clipStart(x, y, w, h float64) { + // Save current graphic state and set clipping area + f.outf("q %.2f %.2f %.2f %.2f re W n", x*f.k, (f.h-y)*f.k, w*f.k, -h*f.k) + // Set up transformation matrix for gradient + f.outf("%.3f 0 0 %.3f %.3f %.3f cm", w*f.k, h*f.k, x*f.k, (f.h-(y+h))*f.k) +} + +func (f *Fpdf) clipEnd() { + // Restore previous graphic state + f.out("Q") +} + +func (f *Fpdf) gradient(tp int, r1, g1, b1 int, r2, g2, b2 int, x1, y1 float64, x2, y2 float64, r float64) { + pos := len(f.gradientList) + f.gradientList = append(f.gradientList, gradientType{tp, colorValueString(r1, g1, b1), + colorValueString(r2, g2, b2), x1, y1, x2, y2, r, 0}) + f.outf("/Sh%d sh", pos) +} + +// Draws a rectangular area with a blending of one color to another. The +// rectangle is of width w and height h. Its upper left corner is positioned at +// point (x, y). +// +// Each color is specified with three component values, one each for red, green +// and blue. The values range from 0 to 255. The first color is specified by +// (r1, g1, b1) and the second color by (r2, g2, b2). +// +// The blending is controlled with a gradient vector that uses normalized +// coordinates in which the lower left corner is position (0, 0) and the upper +// right corner is (1, 1). The vector's origin and destination are specified by +// the points (x1, y1) and (x2, y2). In a linear gradient, blending occurs +// perpendicularly to the vector. The vector does not necessarily need to be +// anchored on the rectangle edge. Color 1 is used up to the origin of the +// vector and color 2 is used beyond the vector's end point. Between the points +// the colors are gradually blended. +// +// See tutorial 13 for an example of this function. +func (f *Fpdf) LinearGradient(x, y, w, h float64, r1, g1, b1 int, r2, g2, b2 int, x1, y1, x2, y2 float64) { + f.clipStart(x, y, w, h) + f.gradient(2, r1, g1, b1, r2, g2, b2, x1, y1, x2, y2, 0) + f.clipEnd() +} + +// Draws a rectangular area with a blending of one color to another. The +// rectangle is of width w and height h. Its upper left corner is positioned at +// point (x, y). +// +// Each color is specified with three component values, one each for red, green +// and blue. The values range from 0 to 255. The first color is specified by +// (r1, g1, b1) and the second color by (r2, g2, b2). +// +// The blending is controlled with a point and a circle, both specified with +// normalized coordinates in which the lower left corner of the rendered +// rectangle is position (0, 0) and the upper right corner is (1, 1). Color 1 +// begins at the origin point specified by (x1, y1). Color 2 begins at the +// circle specified by the center point (x2, y2) and radius r. Colors are +// gradually blended from the origin to the circle. The origin and the circle's +// center do not necessarily have to coincide, but the origin must be within +// the circle to avoid rendering problems. +// +// See tutorial 13 for an example of this function. +func (f *Fpdf) RadialGradient(x, y, w, h float64, r1, g1, b1 int, r2, g2, b2 int, x1, y1, x2, y2, r float64) { + f.clipStart(x, y, w, h) + f.gradient(3, r1, g1, b1, r2, g2, b2, x1, y1, x2, y2, r) + f.clipEnd() +} + // Imports a TrueType, OpenType or Type1 font and makes it available. It is // necessary to generate a font definition file first with the makefont // utility. It is not necessary to call this function for the core PDF fonts @@ -2437,12 +2520,23 @@ func (f *Fpdf) putresourcedict() { f.out("/XObject <<") f.putxobjectdict() f.out(">>") - f.out("/ExtGState <<") count := len(f.blendList) - for j := 1; j < count; j++ { - f.outf("/GS%d %d 0 R", j, f.blendList[j].objNum) + if count > 0 { + f.out("/ExtGState <<") + for j := 1; j < count; j++ { + f.outf("/GS%d %d 0 R", j, f.blendList[j].objNum) + } + f.out(">>") } - f.out(">>") + count = len(f.gradientList) + if count > 0 { + f.out("/Shading <<") + for j := 1; j < count; j++ { + f.outf("/Sh%d %d 0 R", j, f.gradientList[j].objNum) + } + f.out(">>") + } + } func (f *Fpdf) putBlendModes() { @@ -2457,11 +2551,37 @@ func (f *Fpdf) putBlendModes() { } } +func (f *Fpdf) putGradients() { + count := len(f.gradientList) + for j := 1; j < count; j++ { + var f1 int + gr := f.gradientList[j] + if gr.tp == 2 || gr.tp == 3 { + f.newobj() + f.outf("<</FunctionType 2 /Domain [0.0 1.0] /C0 [%s] /C1 [%s] /N 1>>", gr.clr1Str, gr.clr2Str) + f.out("endobj") + f1 = f.n + } + f.newobj() + f.outf("<</ShadingType %d /ColorSpace /DeviceRGB", gr.tp) + if gr.tp == 2 { + f.outf("/Coords [%.3f %.3f %.3f %.3f] /Function %d 0 R /Extend [true true]>>", + gr.x1, gr.y1, gr.x2, gr.y2, f1) + } else if gr.tp == 3 { + f.outf("/Coords [%.3f %.3f 0 %.3f %.3f %.3f] /Function %d 0 R /Extend [true true]>>", + gr.x1, gr.y1, gr.x2, gr.y2, gr.r, f1) + } + f.out("endobj") + f.gradientList[j].objNum = f.n + } +} + func (f *Fpdf) putresources() { if f.err != nil { return } f.putBlendModes() + f.putGradients() f.putfonts() if f.err != nil { return diff --git a/fpdf_test.go b/fpdf_test.go index c121260..08dca43 100644 --- a/fpdf_test.go +++ b/fpdf_test.go @@ -721,3 +721,22 @@ func ExampleFpdf_tutorial12() { // Output: // Successfully generated pdf/tutorial12.pdf } + +// Gradients +func ExampleFpdf_tutorial13() { + pdf := New("", "", "", FONT_DIR) + pdf.SetFont("Helvetica", "", 12) + pdf.AddPage() + pdf.LinearGradient(0, 0, 210, 100, 250, 250, 255, 220, 220, 225, 0, 0, 0, .5) + pdf.LinearGradient(20, 25, 75, 75, 220, 220, 250, 80, 80, 220, 0, .2, 0, .8) + pdf.Rect(20, 25, 75, 75, "D") + pdf.LinearGradient(115, 25, 75, 75, 220, 220, 250, 80, 80, 220, 0, 0, 1, 1) + pdf.Rect(115, 25, 75, 75, "D") + pdf.RadialGradient(20, 120, 75, 75, 220, 220, 250, 80, 80, 220, 0.25, 0.75, 0.25, 0.75, 1) + pdf.Rect(20, 120, 75, 75, "D") + pdf.RadialGradient(115, 120, 75, 75, 220, 220, 250, 80, 80, 220, 0.25, 0.75, 0.75, 0.75, 0.75) + pdf.Rect(115, 120, 75, 75, "D") + pdf.OutputAndClose(docWriter(pdf, 13)) + // Output: + // Successfully generated pdf/tutorial13.pdf +} |