From 5f12bfe3efb23b7a5d2613c4bebbb8e57f48e4d0 Mon Sep 17 00:00:00 2001
From: Sander Schobers <sander@schobers.eu>
Date: Mon, 26 Feb 2018 07:51:58 +0100
Subject: [PATCH] Exposed new bitmap flag manipulation.

---
 allegro5/bitmap.go        | 41 +++++++++++++--------------------------
 allegro5/flagmut.go       | 15 +++++++++-----
 allegro5/newbitmapflag.go | 31 +++++++++++++++++++++++++++++
 3 files changed, 54 insertions(+), 33 deletions(-)
 create mode 100644 allegro5/newbitmapflag.go

diff --git a/allegro5/bitmap.go b/allegro5/bitmap.go
index ebb4af2..20b96bc 100644
--- a/allegro5/bitmap.go
+++ b/allegro5/bitmap.go
@@ -60,33 +60,14 @@ func NewBitmap(width, height int) (*Bitmap, error) {
 	return &Bitmap{b, width, height}, nil
 }
 
-type newBmpFlagsCapture struct {
-	cap C.int
-}
-
-func captureNewBmpFlags() *newBmpFlagsCapture {
-	var cap = C.al_get_new_bitmap_flags()
-	return &newBmpFlagsCapture{cap}
-}
-
-func (c *newBmpFlagsCapture) Mut(mut func(*flagMut)) {
-	var m = &flagMut{c.cap}
-	mut(m)
-	C.al_set_new_bitmap_flags(m.flg)
-}
-
-func (c *newBmpFlagsCapture) Revert() {
-	C.al_set_new_bitmap_flags(c.cap)
-}
-
 // NewBitmapFromImage creates a new bitmap starting from a Go native image (image.Image)
 func NewBitmapFromImage(im image.Image, video bool) (*Bitmap, error) {
-	var newBmpFlags = captureNewBmpFlags()
+	var newBmpFlags = CaptureNewBitmapFlags()
 	defer newBmpFlags.Revert()
-	newBmpFlags.Mut(func(m *flagMut) {
-		m.Unset(C.ALLEGRO_VIDEO_BITMAP)
-		m.Set(C.ALLEGRO_MEMORY_BITMAP)
-		m.Set(C.ALLEGRO_MIN_LINEAR)
+	newBmpFlags.Mutate(func(m FlagMutation) {
+		m.Unset(NewBitmapFlagVideoBitmap)
+		m.Set(NewBitmapFlagMemoryBitmap)
+		m.Set(NewBitmapFlagMinLinear)
 	})
 	var bnd = im.Bounds()
 	width, height := bnd.Dx(), bnd.Dy()
@@ -115,10 +96,10 @@ func NewBitmapFromImage(im image.Image, video bool) (*Bitmap, error) {
 	}
 	C.al_unlock_bitmap(b)
 	if video {
-		newBmpFlags.Mut(func(m *flagMut) {
-			m.Unset(C.ALLEGRO_MEMORY_BITMAP)
-			m.Set(C.ALLEGRO_VIDEO_BITMAP)
-			m.Set(C.ALLEGRO_MIN_LINEAR)
+		newBmpFlags.Mutate(func(m FlagMutation) {
+			m.Unset(NewBitmapFlagMemoryBitmap)
+			m.Set(NewBitmapFlagVideoBitmap)
+			m.Set(NewBitmapFlagMinLinear)
 		})
 		C.al_convert_bitmap(b)
 	}
@@ -203,6 +184,10 @@ func (b *Bitmap) Height() int {
 	return b.height
 }
 
+func (b *Bitmap) SetAsTarget() {
+	C.al_set_target_bitmap(b.bitmap)
+}
+
 // Destroy destroys the bitmap
 func (b *Bitmap) Destroy() {
 	C.al_destroy_bitmap(b.bitmap)
diff --git a/allegro5/flagmut.go b/allegro5/flagmut.go
index b4113c3..f4547d0 100644
--- a/allegro5/flagmut.go
+++ b/allegro5/flagmut.go
@@ -3,16 +3,21 @@ package allegro5
 // #include <stdlib.h>
 import "C"
 
+type FlagMutation interface {
+	Set(f NewBitmapFlag)
+	Unset(f NewBitmapFlag)
+}
+
 type flagMut struct {
 	flg C.int
 }
 
-func (m *flagMut) Set(f C.int) {
-	m.flg |= f
+func (m *flagMut) Set(f NewBitmapFlag) {
+	m.flg |= C.int(f)
 }
 
-func (m *flagMut) Unset(f C.int) {
-	if m.flg&f == f {
-		m.flg ^= f
+func (m *flagMut) Unset(f NewBitmapFlag) {
+	if m.flg&C.int(f) == C.int(f) {
+		m.flg ^= C.int(f)
 	}
 }
diff --git a/allegro5/newbitmapflag.go b/allegro5/newbitmapflag.go
new file mode 100644
index 0000000..645b135
--- /dev/null
+++ b/allegro5/newbitmapflag.go
@@ -0,0 +1,31 @@
+package allegro5
+
+// #include <allegro5/allegro.h>
+import "C"
+
+type NewBitmapFlag int
+
+const (
+	NewBitmapFlagMemoryBitmap = NewBitmapFlag(C.ALLEGRO_MEMORY_BITMAP)
+	NewBitmapFlagVideoBitmap  = NewBitmapFlag(C.ALLEGRO_VIDEO_BITMAP)
+	NewBitmapFlagMinLinear    = NewBitmapFlag(C.ALLEGRO_MIN_LINEAR)
+)
+
+type NewBitmapFlagsCapture struct {
+	cap C.int
+}
+
+func CaptureNewBitmapFlags() *NewBitmapFlagsCapture {
+	var cap = C.al_get_new_bitmap_flags()
+	return &NewBitmapFlagsCapture{cap}
+}
+
+func (c *NewBitmapFlagsCapture) Mutate(mut func(FlagMutation)) {
+	var m = &flagMut{c.cap}
+	mut(m)
+	C.al_set_new_bitmap_flags(m.flg)
+}
+
+func (c *NewBitmapFlagsCapture) Revert() {
+	C.al_set_new_bitmap_flags(c.cap)
+}