[opentype] CPAL support

Author: benoitkugler

font/opentype/tables/glyphs_color_test.go

@@ -35,3 +35,19 @@ func TestCOLR(t *testing.T) {
 	tu.Assert(t, g1 == BaseGlyph{0, 0, 11} && g2 == BaseGlyph{2, 11, 18})
 	tu.Assert(t, colr.LayerRecords[0].PaletteIndex == 4)
 }
+
+func TestCPAL(t *testing.T) {
+	ft := readFontFile(t, "color/NotoColorEmoji-Regular.ttf")
+	cpal, _, err := ParseCPAL(readTable(t, ft, "CPAL"))
+	tu.AssertNoErr(t, err)
+	tu.Assert(t, cpal.Version == 0)
+	tu.Assert(t, cpal.numPaletteEntries == 5921)
+	tu.Assert(t, cpal.numPalettes == 1 && len(cpal.ColorRecordIndices) == 1)
+
+	ft = readFontFile(t, "color/CoralPixels-Regular.ttf")
+	cpal, _, err = ParseCPAL(readTable(t, ft, "CPAL"))
+	tu.AssertNoErr(t, err)
+	tu.Assert(t, cpal.Version == 0)
+	tu.Assert(t, cpal.numPaletteEntries == 32)
+	tu.Assert(t, cpal.numPalettes == 2 && len(cpal.ColorRecordIndices) == 2)
+}

font/opentype/tables/glyphs_cpal_gen.go

@@ -1,38 +1,15 @@
 package tables
 
-import "fmt"
-
-func ParseCPAL(src []byte) (CPAL1, error) {
-	header, _, err := parseCpal0(src)
-	if err != nil {
-		return CPAL1{}, err
-	}
-	switch header.Version {
-	case 0:
-		return CPAL1{cpal0: header}, nil
-	case 1:
-		out, _, err := ParseCPAL1(src)
-		return out, err
-	default:
-		return CPAL1{}, fmt.Errorf("unsupported version for CPAL: %d", header.Version)
-	}
-}
-
 // https://learn.microsoft.com/en-us/typography/opentype/spec/cpal
-type cpal0 struct {
+//
+// For now, only the CPAL version 0 is supported.
+type CPAL struct {
 	Version            uint16        //	Table version number
 	numPaletteEntries  uint16        //	Number of palette entries in each palette.
 	numPalettes        uint16        //	Number of palettes in the table.
 	numColorRecords    uint16        //	Total number of color records, combined for all palettes.
-	ColorRecordsArray  []ColorRecord `arrayCount:"ComputedField-numColorRecords" offsetSize:"Offset32"` //	Offset from the beginning of CPAL table to the first ColorRecord.
-	ColorRecordIndices []uint16      `arrayCount:"ComputedField-numPalettes"`                           //[numPalettes]	Index of each palette’s first color record in the combined color record array.
-}
-
-type CPAL1 struct {
-	cpal0
-	paletteTypesArrayOffset       Offset32 // Offset from the beginning of CPAL table to the Palette Types Array. Set to 0 if no array is provided.
-	paletteLabelsArrayOffset      Offset32 // Offset from the beginning of CPAL table to the Palette Labels Array. Set to 0 if no array is provided.
-	paletteEntryLabelsArrayOffset Offset32 // Offset from the beginning of CPAL table to the Palette Entry Labels Array. Set to 0 if no array is provided.
+	ColorRecordsArray  []ColorRecord `arrayCount:"ComputedField-numColorRecords" offsetSize:"Offset32"` // Offset from the beginning of CPAL table to the first ColorRecord.
+	ColorRecordIndices []uint16      `arrayCount:"ComputedField-numPalettes"`                           // [numPalettes] Index of each palette’s first color record in the combined color record array.
 }
 
 type ColorRecord struct {