implemented imapge pattern repeat types

backend/backendbase/base.go

@@ -109,8 +109,19 @@ type Image interface {
 type ImagePatternData struct {
 	Image     Image
 	Transform [9]float64
+	Repeat    ImagePatternRepeat
 }
 
+type ImagePatternRepeat uint8
+
+// Image pattern repeat constants
+const (
+	Repeat ImagePatternRepeat = iota
+	RepeatX
+	RepeatY
+	NoRepeat
+)
+
 type ImagePattern interface {
 	Delete()
 	Replace(data ImagePatternData)

backend/gogl/gogl.go

@@ -445,6 +445,16 @@ func (b *GoGLBackend) useShader(style *backendbase.FillStyle) (vertexLoc uint32)
 			f32mat[i] = float32(v)
 		}
 		gl.UniformMatrix3fv(b.ipr.ImageTransform, 1, false, &f32mat[0])
+		switch ipd.Repeat {
+		case backendbase.Repeat:
+			gl.Uniform2f(b.ipr.Repeat, 1, 1)
+		case backendbase.RepeatX:
+			gl.Uniform2f(b.ipr.Repeat, 1, 0)
+		case backendbase.RepeatY:
+			gl.Uniform2f(b.ipr.Repeat, 0, 1)
+		case backendbase.NoRepeat:
+			gl.Uniform2f(b.ipr.Repeat, 0, 0)
+		}
 		gl.Uniform1f(b.ipr.GlobalAlpha, float32(style.Color.A)/255)
 		return b.ipr.Vertex
 	}
@@ -508,6 +518,16 @@ func (b *GoGLBackend) useAlphaShader(style *backendbase.FillStyle, alphaTexSlot
 			f32mat[i] = float32(v)
 		}
 		gl.UniformMatrix3fv(b.ipr.ImageTransform, 1, false, &f32mat[0])
+		switch ipd.Repeat {
+		case backendbase.Repeat:
+			gl.Uniform2f(b.ipr.Repeat, 1, 1)
+		case backendbase.RepeatX:
+			gl.Uniform2f(b.ipr.Repeat, 1, 0)
+		case backendbase.RepeatY:
+			gl.Uniform2f(b.ipr.Repeat, 0, 1)
+		case backendbase.NoRepeat:
+			gl.Uniform2f(b.ipr.Repeat, 0, 0)
+		}
 		gl.Uniform1i(b.ipar.AlphaTex, alphaTexSlot)
 		gl.Uniform1f(b.ipar.GlobalAlpha, float32(style.Color.A)/255)
 		return b.ipar.Vertex, b.ipar.AlphaTexCoord

backend/gogl/shaders.go

@@ -133,10 +133,18 @@ varying vec2 v_cp;
 uniform vec2 imageSize;
 uniform sampler2D image;
 uniform mat3 imageTransform;
+uniform vec2 repeat;
 uniform float globalAlpha;
 void main() {
-	vec3 tfp = vec3(v_cp, 1.0) * imageTransform;
+	vec3 tfpt = vec3(v_cp, 1.0) * imageTransform;
-	vec4 col = texture2D(image, mod(tfp.xy / imageSize, 1.0));
+	vec2 imgpt = tfpt.xy / imageSize;
+	vec4 col = texture2D(image, mod(imgpt, 1.0));
+	if (imgpt.x < 0.0 || imgpt.x > 1.0) {
+		col *= repeat.x;
+	}
+	if (imgpt.y < 0.0 || imgpt.y > 1.0) {
+		col *= repeat.y;
+	}
 	col.a *= globalAlpha;
     gl_FragColor = col;
 }`
@@ -262,11 +270,19 @@ varying vec2 v_atc;
 uniform vec2 imageSize;
 uniform sampler2D image;
 uniform mat3 imageTransform;
+uniform vec2 repeat;
 uniform sampler2D alphaTex;
 uniform float globalAlpha;
 void main() {
-	vec3 tfp = vec3(v_cp, 1.0) * imageTransform;
+	vec3 tfpt = vec3(v_cp, 1.0) * imageTransform;
-	vec4 col = texture2D(image, mod(tfp.xy / imageSize, 1.0));
+	vec2 imgpt = tfpt.xy / imageSize;
+	vec4 col = texture2D(image, mod(imgpt, 1.0));
+	if (imgpt.x < 0.0 || imgpt.x > 1.0) {
+		col *= repeat.x;
+	}
+	if (imgpt.y < 0.0 || imgpt.y > 1.0) {
+		col *= repeat.y;
+	}
     col.a *= texture2D(alphaTex, v_atc).a * globalAlpha;
 	gl_FragColor = col;
 }`
@@ -409,6 +425,7 @@ type imagePatternShader struct {
 	ImageSize      int32
 	Image          int32
 	ImageTransform int32
+	Repeat         int32
 	GlobalAlpha    int32
 }
 
@@ -457,6 +474,7 @@ type imagePatternAlphaShader struct {
 	ImageSize      int32
 	Image          int32
 	ImageTransform int32
+	Repeat         int32
 	AlphaTex       int32
 	GlobalAlpha    int32
 }

canvas.go

@@ -223,7 +223,7 @@ func (cv *Canvas) parseStyle(value ...interface{}) drawStyle {
 		switch v := value[0].(type) {
 		case *Image, string:
 			if _, ok := imagePatterns[v]; !ok {
-				imagePatterns[v] = cv.CreatePattern(v, "")
+				imagePatterns[v] = cv.CreatePattern(v, Repeat)
 			}
 			style.imagePattern = imagePatterns[v]
 		case *ImagePattern:

images.go

@@ -190,13 +190,25 @@ type ImagePattern struct {
 	cv  *Canvas
 	img *Image
 	tf  [9]float64
+	rep imagePatternRepeat
 	ip  backendbase.ImagePattern
 }
 
+type imagePatternRepeat uint8
+
+// Image pattern repeat constants
+const (
+	Repeat   imagePatternRepeat = imagePatternRepeat(backendbase.Repeat)
+	RepeatX                     = imagePatternRepeat(backendbase.RepeatX)
+	RepeatY                     = imagePatternRepeat(backendbase.RepeatY)
+	NoRepeat                    = imagePatternRepeat(backendbase.NoRepeat)
+)
+
 func (ip *ImagePattern) data() backendbase.ImagePatternData {
 	return backendbase.ImagePatternData{
 		Image:     ip.img.img,
 		Transform: ip.tf,
+		Repeat:    backendbase.ImagePatternRepeat(ip.rep),
 	}
 }
 
@@ -214,10 +226,12 @@ func (ip *ImagePattern) SetTransform(tf [6]float64) {
 
 // CreatePattern creates a new image pattern with the specified
 // image and repetition
-func (cv *Canvas) CreatePattern(src interface{}, repetition string) *ImagePattern {
+func (cv *Canvas) CreatePattern(src interface{}, repeat imagePatternRepeat) *ImagePattern {
 	ip := &ImagePattern{
 		cv:  cv,
 		img: cv.getImage(src),
+		rep: repeat,
+		tf:  [9]float64{1, 0, 0, 0, 1, 0, 0, 0, 1},
 	}
 	if ip.img != nil {
 		ip.ip = cv.b.LoadImagePattern(ip.data())