gx: add .rgba8(), .bgra8(), .abgr8() methods to gx.Color (#7911)

vlib/gx/color.v

@@ -183,6 +183,27 @@ pub fn (c Color) str() string {
 	return 'Color{$c.r, $c.g, $c.b, $c.a}'
 }
 
+// rgba8 - convert a color value to an int in the RGBA8 order.
+// see https://developer.apple.com/documentation/coreimage/ciformat
+[inline]
+pub fn (c Color) rgba8() int {
+	return (int(c.r) << 24) + (int(c.g) << 16) + (int(c.b) << 8) + int(c.a)
+}
+
+// bgra8 - convert a color value to an int in the BGRA8 order.
+// see https://developer.apple.com/documentation/coreimage/ciformat
+[inline]
+pub fn (c Color) bgra8() int {
+	return (int(c.b) << 24) + (int(c.g) << 16) + (int(c.r) << 8) + int(c.a)
+}
+
+// abgr8 - convert a color value to an int in the ABGR8 order. 
+// see https://developer.apple.com/documentation/coreimage/ciformat
+[inline]
+pub fn (c Color) abgr8() int {
+	return (int(c.a) << 24) + (int(c.b) << 16) + (int(c.g) << 8) + int(c.r)
+}
+
 const (
 	string_colors = {
 		'black': black

vlib/gx/color_test.v

@@ -1,16 +1,12 @@
 import gx
 
-
 fn test_hex() {
 	// valid colors
 	a := gx.hex(0x6c5ce7ff)
 	b := gx.rgba(108, 92, 231, 255)
-
 	assert a.eq(b)
-
 	// doesn't give right value with short hex value
 	short := gx.hex(0xfff)
-    
 	assert !short.eq(gx.white)
 }
 
@@ -18,7 +14,6 @@ fn test_add() {
 	a := gx.rgba(100, 100, 100, 100)
 	b := gx.rgba(100, 100, 100, 100)
 	r := gx.rgba(200, 200, 200, 200)
-
 	assert (a + b).eq(r)
 }
 
@@ -26,7 +21,6 @@ fn test_sub() {
 	a := gx.rgba(100, 100, 100, 100)
 	b := gx.rgba(100, 100, 100, 100)
 	r := gx.rgba(0, 0, 0, 0)
-
 	assert (a - b).eq(r)
 }
 
@@ -34,7 +28,6 @@ fn test_mult() {
 	a := gx.rgba(10, 10, 10, 10)
 	b := gx.rgba(10, 10, 10, 10)
 	r := gx.rgba(100, 100, 100, 100)
-
 	assert (a * b).eq(r)
 }
 
@@ -42,6 +35,29 @@ fn test_div() {
 	a := gx.rgba(100, 100, 100, 100)
 	b := gx.rgba(10, 10, 10, 10)
 	r := gx.rgba(10, 10, 10, 10)
-
 	assert (a / b).eq(r)
 }
+
+fn test_rgba8() {
+	assert gx.white.rgba8() == -1
+	assert gx.black.rgba8() == 255
+	assert gx.red.rgba8() == -16776961
+	assert gx.green.rgba8() == 16711935
+	assert gx.blue.rgba8() == 65535
+}
+
+fn test_bgra8() {
+	assert gx.white.bgra8() == -1
+	assert gx.black.bgra8() == 255
+	assert gx.red.bgra8() == 65535
+	assert gx.green.bgra8() == 16711935
+	assert gx.blue.bgra8() == -16776961
+}
+
+fn test_abgr8() {
+	assert gx.white.abgr8() == -1
+	assert gx.black.abgr8() == -16777216
+	assert gx.red.abgr8() == -16776961
+	assert gx.green.abgr8() == -16711936
+	assert gx.blue.abgr8() == -65536
+}