removed some dead code; small code improvements

backend/goglbackend/gogl.go

@@ -2,7 +2,6 @@ package goglbackend
 
 import (
 	"fmt"
-	"image/color"
 	"math"
 
 	"github.com/tfriedel6/canvas/backend/backendbase"
@@ -275,19 +274,6 @@ func (b *GoGLBackendOffscreen) AsImage() backendbase.Image {
 	return &b.offscrImg
 }
 
-type glColor struct {
-	r, g, b, a float64
-}
-
-func colorGoToGL(c color.RGBA) glColor {
-	var glc glColor
-	glc.r = float64(c.R) / 255
-	glc.g = float64(c.G) / 255
-	glc.b = float64(c.B) / 255
-	glc.a = float64(c.A) / 255
-	return glc
-}
-
 func (b *GoGLBackend) useShader(style *backendbase.FillStyle, useAlpha bool, alphaTexSlot int32) (vertexLoc, alphaTexCoordLoc uint32) {
 	gl.UseProgram(b.shd.ID)
 	gl.Uniform2f(b.shd.CanvasSize, float32(b.fw), float32(b.fh))
@@ -355,8 +341,11 @@ func (b *GoGLBackend) useShader(style *backendbase.FillStyle, useAlpha bool, alp
 		return b.shd.Vertex, b.shd.TexCoord
 	}
 
-	c := colorGoToGL(style.Color)
-	gl.Uniform4f(b.shd.Color, float32(c.r), float32(c.g), float32(c.b), float32(c.a))
+	cr := float32(style.Color.R) / 255
+	cg := float32(style.Color.G) / 255
+	cb := float32(style.Color.B) / 255
+	ca := float32(style.Color.A) / 255
+	gl.Uniform4f(b.shd.Color, cr, cg, cb, ca)
 	gl.Uniform1f(b.shd.GlobalAlpha, 1)
 	gl.Uniform1i(b.shd.Func, shdFuncSolid)
 	return b.shd.Vertex, b.shd.TexCoord

canvas.go

@@ -179,16 +179,6 @@ type offscreenBuffer struct {
 	alpha            bool
 }
 
-type gaussianShader struct {
-	id          uint32
-	vertex      uint32
-	texCoord    uint32
-	canvasSize  int32
-	kernelScale int32
-	image       int32
-	kernel      int32
-}
-
 // SetFillStyle sets the color, gradient, or image for any fill calls. To set a
 // color, there are several acceptable formats: 3 or 4 int values for RGB(A) in
 // the range 0-255, 3 or 4 float values for RGB(A) in the range 0-1, hex strings
@@ -362,6 +352,7 @@ func (cv *Canvas) SetLineDash(dash []float64) {
 	cv.state.lineDashOffset = 0
 }
 
+// SetLineDashOffset sets the line dash offset
 func (cv *Canvas) SetLineDashOffset(offset float64) {
 	cv.state.lineDashOffset = offset
 }

color.go

@@ -8,49 +8,6 @@ import (
 	"strings"
 )
 
-type glColor struct {
-	r, g, b, a float64
-}
-
-func colorGoToGL(color color.Color) glColor {
-	ir, ig, ib, ia := color.RGBA()
-	var c glColor
-	c.r = float64(ir) / 65535
-	c.g = float64(ig) / 65535
-	c.b = float64(ib) / 65535
-	c.a = float64(ia) / 65535
-	return c
-}
-
-func colorGLToGo(c glColor) color.RGBA {
-	if c.r < 0 {
-		c.r = 0
-	} else if c.r > 1 {
-		c.r = 1
-	}
-	if c.g < 0 {
-		c.g = 0
-	} else if c.g > 1 {
-		c.g = 1
-	}
-	if c.b < 0 {
-		c.b = 0
-	} else if c.b > 1 {
-		c.b = 1
-	}
-	if c.a < 0 {
-		c.a = 0
-	} else if c.a > 1 {
-		c.a = 1
-	}
-	return color.RGBA{
-		R: uint8(c.r * 255),
-		G: uint8(c.g * 255),
-		B: uint8(c.b * 255),
-		A: uint8(c.a * 255),
-	}
-}
-
 func parseHexRune(rn rune) (int, bool) {
 	switch {
 	case rn >= '0' && rn <= '9':

path2d.go

@@ -390,8 +390,7 @@ func runSubPaths(path []pathPoint, close bool, fn func(subPath []pathPoint) bool
 			continue
 		}
 		if i >= start+3 {
-			end := i
-			if runSubPath(path[start:end], close, fn) {
+			if runSubPath(path[start:i], close, fn) {
 				return
 			}
 		}

paths.go

@@ -400,11 +400,11 @@ func appendSubPathTriangles(tris [][2]float64, mat mat, path []pathPoint) [][2]f
 	last := path[len(path)-1]
 	if last.flags&pathIsConvex != 0 {
 		p0, p1 := path[0].pos.mulMat(mat), path[1].pos.mulMat(mat)
-		last := len(path)
-		if path[0].pos == path[last-1].pos {
-			last--
+		lastIdx := len(path)
+		if path[0].pos == path[lastIdx-1].pos {
+			lastIdx--
 		}
-		for i := 2; i < last; i++ {
+		for i := 2; i < lastIdx; i++ {
 			p2 := path[i].pos.mulMat(mat)
 			tris = append(tris, p0, p1, p2)
 			p1 = p2