From b821f1635609bbff9e0b0c8b9acb488119332d28 Mon Sep 17 00:00:00 2001 From: Nigel Tao Date: Sat, 19 Oct 2013 10:04:03 +1100 Subject: [PATCH] freetype/truetype: WCVTP, RCVT opcodes. R=bsiegert CC=golang-dev https://codereview.appspot.com/14802046 --- freetype/truetype/hint.go | 56 +++++++++++++++++++++++++----- freetype/truetype/opcodes.go | 6 ++-- freetype/truetype/truetype_test.go | 2 +- 3 files changed, 52 insertions(+), 12 deletions(-) diff --git a/freetype/truetype/hint.go b/freetype/truetype/hint.go index 317b70b..955b36b 100644 --- a/freetype/truetype/hint.go +++ b/freetype/truetype/hint.go @@ -58,6 +58,10 @@ type Hinter struct { // and glyph's contour boundaries. points [numZone][numPointType][]Point ends []int + + // scaledCVT is the lazily initialized scaled Control Value Table. + scaledCVTInitialized bool + scaledCVT []f26dot6 } // graphicsState is described at https://developer.apple.com/fonts/TTRefMan/RM04/Chap4.html @@ -169,6 +173,7 @@ func (h *Hinter) run(program []byte, pCurrent, pUnhinted, pInFontUnits []Point, h.points[glyphZone][unhinted] = pUnhinted h.points[glyphZone][inFontUnits] = pInFontUnits h.ends = ends + h.scaledCVTInitialized = false if len(program) > 50000 { return errors.New("truetype: hinting: too many instructions") @@ -514,7 +519,7 @@ func (h *Hinter) run(program []byte, pCurrent, pUnhinted, pInFontUnits []Point, case opMIAP0, opMIAP1: top -= 2 i := h.stack[top] - distance := h.cvt(h.stack[top+1]) + distance := h.getScaledCVT(h.stack[top+1]) if h.gs.zp[0] == 0 { p := h.point(0, unhinted, i) q := h.point(0, current, i) @@ -558,6 +563,13 @@ func (h *Hinter) run(program []byte, pCurrent, pUnhinted, pInFontUnits []Point, } h.stack[top-1] = h.store[i] + case opWCVTP: + top -= 2 + h.setScaledCVT(h.stack[top], f26dot6(h.stack[top+1])) + + case opRCVT: + h.stack[top-1] = int32(h.getScaledCVT(h.stack[top-1])) + case opMPPEM, opMPS: if top >= len(h.stack) { return errors.New("truetype: hinting: stack overflow") @@ -867,7 +879,7 @@ func (h *Hinter) run(program []byte, pCurrent, pUnhinted, pInFontUnits []Point, top -= 2 i := h.stack[top] - cvtDist := h.cvt(h.stack[top+1]) + cvtDist := h.getScaledCVT(h.stack[top+1]) if (cvtDist - h.gs.singleWidth).abs() < h.gs.singleWidthCutIn { if cvtDist >= 0 { cvtDist = +h.gs.singleWidth @@ -1011,14 +1023,42 @@ func (h *Hinter) run(program []byte, pCurrent, pUnhinted, pInFontUnits []Point, return nil } -// cvt returns the scaled value from the font's Control Value Table. -func (h *Hinter) cvt(i int32) f26dot6 { - i *= 2 - if i < 0 || len(h.font.cvt) < int(i) { +func (h *Hinter) initializeScaledCVT() { + h.scaledCVTInitialized = true + if n := len(h.font.cvt) / 2; n <= cap(h.scaledCVT) { + h.scaledCVT = h.scaledCVT[:n] + } else { + if n < 32 { + n = 32 + } + h.scaledCVT = make([]f26dot6, len(h.font.cvt)/2, n) + } + for i := range h.scaledCVT { + unscaled := uint16(h.font.cvt[2*i])<<8 | uint16(h.font.cvt[2*i+1]) + h.scaledCVT[i] = f26dot6(h.font.scale(h.scale * int32(int16(unscaled)))) + } +} + +// getScaledCVT returns the scaled value from the font's Control Value Table. +func (h *Hinter) getScaledCVT(i int32) f26dot6 { + if !h.scaledCVTInitialized { + h.initializeScaledCVT() + } + if i < 0 || len(h.scaledCVT) <= int(i) { return 0 } - cv := uint16(h.font.cvt[i])<<8 | uint16(h.font.cvt[i+1]) - return f26dot6(h.font.scale(h.scale * int32(int16(cv)))) + return h.scaledCVT[i] +} + +// setScaledCVT overrides the scaled value from the font's Control Value Table. +func (h *Hinter) setScaledCVT(i int32, v f26dot6) { + if !h.scaledCVTInitialized { + h.initializeScaledCVT() + } + if i < 0 || len(h.scaledCVT) <= int(i) { + return + } + h.scaledCVT[i] = v } func (h *Hinter) point(zonePointer uint32, pt pointType, i int32) *Point { diff --git a/freetype/truetype/opcodes.go b/freetype/truetype/opcodes.go index 12693c0..7b16e5d 100644 --- a/freetype/truetype/opcodes.go +++ b/freetype/truetype/opcodes.go @@ -78,8 +78,8 @@ const ( opNPUSHW = 0x41 // PUSH N Words opWS = 0x42 // Write Store opRS = 0x43 // Read Store - opWCVTP = 0x44 - opRCVT = 0x45 + opWCVTP = 0x44 // Write Control Value Table in Pixel units + opRCVT = 0x45 // Read Control Value Table entry opGC0 = 0x46 opGC1 = 0x47 opSCFS = 0x48 @@ -275,7 +275,7 @@ var popCount = [256]uint8{ 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, // 0x10 - 0x1f 1, 1, 0, 2, 0, 1, 1, q, q, q, 2, 1, 1, 0, 1, 1, // 0x20 - 0x2f 0, 0, q, q, q, q, q, q, q, 0, q, q, 0, 0, 2, 2, // 0x30 - 0x3f - 0, 0, 2, 1, q, q, q, q, q, q, q, 0, 0, 0, 0, 0, // 0x40 - 0x4f + 0, 0, 2, 1, 2, 1, q, q, q, q, q, 0, 0, 0, 0, 0, // 0x40 - 0x4f 2, 2, 2, 2, 2, 2, 1, 1, 1, 0, 2, 2, 1, q, 1, 1, // 0x50 - 0x5f 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 0x60 - 0x6f q, q, q, q, q, q, 1, 1, 2, 2, 0, q, 0, 0, 1, 1, // 0x70 - 0x7f diff --git a/freetype/truetype/truetype_test.go b/freetype/truetype/truetype_test.go index 1b63fd1..2a29765 100644 --- a/freetype/truetype/truetype_test.go +++ b/freetype/truetype/truetype_test.go @@ -253,7 +253,7 @@ var scalingTestCases = []struct { }{ {"luxisr", 12, -1}, {"x-arial-bold", 11, 0}, - {"x-deja-vu-sans-oblique", 17, 0}, + {"x-deja-vu-sans-oblique", 17, 1}, {"x-droid-sans-japanese", 9, 0}, {"x-times-new-roman", 13, 0}, }