From e3e16e2fb021b61e45b01113cb1654cd7e4911c6 Mon Sep 17 00:00:00 2001
From: rodri <rgl@antares-labs.eu>
Date: Sat, 13 Jun 2020 21:35:02 +0000
Subject: added basic canvas and layer management.

---
 canvas.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
 create mode 100644 canvas.c

(limited to 'canvas.c')

diff --git a/canvas.c b/canvas.c
new file mode 100644
index 0000000..a017fb0
--- /dev/null
+++ b/canvas.c
@@ -0,0 +1,30 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <geometry.h>
+#include "dat.h"
+#include "fns.h"
+
+static int
+alphachan(ulong chan)
+{
+	for(; chan; chan >>= 8)
+		if(TYPE(chan) == CAlpha)
+			return 1;
+	return 0;
+}
+
+Canvas*
+newcanvas(Point2 p, Rectangle r, ulong chan)
+{
+	Canvas *c;
+
+	c = emalloc(sizeof(Canvas));
+	c->p = p;
+	c->bx = Vec2(1,0);
+	c->by = Vec2(0,1);
+	c->image = eallocimage(display, r, chan, 0, alphachan(chan)? DTransparent: DNofill);
+	memset(&c->layers, 0, sizeof(Layer));
+	c->layers.next = &c->layers;
+	c->layers.prev = &c->layers;
+}
-- 
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