TSS now supports PNG image textures

internal/styles/tss/build.go

@@ -1,32 +1,36 @@
 package tss
 
+import "os"
+import "io"
 import "fmt"
 import "image"
 import "errors"
 import "image/color"
+import _ "image/png"
+import "path/filepath"
 import "git.tebibyte.media/tomo/tomo"
 import "git.tebibyte.media/tomo/tomo/event"
+import "git.tebibyte.media/tomo/tomo/canvas"
 import "git.tebibyte.media/tomo/backend/style"
 
 type styleBuilder struct {
-	sheet Sheet
-}
-
-type faceKey struct {
-	name string
-	size int
+	sheet      Sheet
+	workingDir string
+	textures   map[string] canvas.TextureCloser
 }
 
 // BuildStyle builds a Tomo style from the specified sheet. Resources associated
 // with it (such as textures) can be freed by closing the returned cookie.
 func BuildStyle (sheet Sheet) (*style.Style, event.Cookie, error) {
 	builder := &styleBuilder {
-		sheet: sheet,
+		sheet:      sheet,
+		workingDir: filepath.Dir(sheet.Path),
 	}
 	return builder.build()
 }
 
 func (this *styleBuilder) build () (*style.Style, event.Cookie, error) {
+	// ensure the sheet is flattened (all vars are resolved)
 	err := this.sheet.Flatten()
 	if err != nil { return nil, nil, err }
 	
@@ -41,6 +45,7 @@ func (this *styleBuilder) build () (*style.Style, event.Cookie, error) {
 		return color.RGBA { R: 255, B: 255, A: 255 }
 	}
 
+	// construct style and get colors
 	cookies := []event.Cookie { }
 	sty := &style.Style {
 		Rules: make([]style.Rule, len(this.sheet.Rules)),
@@ -53,6 +58,7 @@ func (this *styleBuilder) build () (*style.Style, event.Cookie, error) {
 		},
 	}
 
+	// build style rules from the sheet's rule slice
 	for index, rule := range this.sheet.Rules {
 		styleRule := style.Rule {
 			Role: tomo.Role {
@@ -73,8 +79,10 @@ func (this *styleBuilder) build () (*style.Style, event.Cookie, error) {
 		sty.Rules[index] = styleRule
 	}
 
-	// TODO include all the faces in this.faces (ONCE EACH) in the
-	// multicookie
+	// add each texture to the cookies list
+	for _, texture := range this.textures {
+		cookies = append(cookies, closerCookie { Closer: texture })
+	}
 	
 	return sty, event.MultiCookie(cookies...), nil
 }
@@ -166,7 +174,14 @@ func (this *styleBuilder) buildAttr (name string, attr []ValueList) (tomo.Attr,
 		return nil, nil, errWrongType()
 		
 	case "Texture":
-		// TODO load image from file
+		err := expectSingleSingle()
+		if err != nil { return nil, nil, err }
+		if name, ok := attr[0][0].(ValueString); ok {
+			texture, err := this.texture(string(name))
+			if err != nil { return nil, nil, err }
+			return tomo.ATexture(texture), nil, nil
+		}
+		return nil, nil, errWrongType()
 	
 	case "TextureMode":
 		err := expectSingleSingle()
@@ -306,6 +321,19 @@ func (this *styleBuilder) buildAttr (name string, attr []ValueList) (tomo.Attr,
 	return nil, nil, errors.New(fmt.Sprintf("unimplemented attribute name %s", name))
 }
 
+func (this *styleBuilder) texture (path string) (canvas.TextureCloser, error) {
+	path = filepath.Join(this.workingDir, path)
+	if texture, ok := this.textures[path]; ok {
+		return texture, nil
+	}
+	file, err := os.Open(path)
+	if err != nil { return nil, err }
+	defer file.Close()
+	rawImage, _, err := image.Decode(file)
+	if err != nil { return nil, err }
+	return tomo.NewTexture(rawImage), nil
+}
+
 func buildAttrBorder (attr []ValueList) (tomo.Attr, error) {
 	borders := make([]tomo.Border, len(attr))
 	for index, list := range attr {
@@ -371,3 +399,9 @@ func copyBorderValue[T any, U ~[]T] (destination, source U) bool {
 	}
 }
 
+type closerCookie struct {
+	io.Closer
+}
+func (cookie closerCookie) Close () {
+	cookie.Closer.Close()
+}