implement stroke operation

2 files changed, 29 insertions, 8 deletions

diff --git a/drawing/drawing.ha b/drawing/drawing.ha
index 063577d..a7d9e1f 100644
--- a/drawing/drawing.ha
+++ b/drawing/drawing.ha
@@ -1,8 +1,7 @@
-use sdl2;
 use fmt;
 use io;
 use endian;
-use math::random;
+use math;
 
 export def CHUNKSIZE = 512;
 
@@ -53,6 +52,8 @@ export fn outline_picture(pic: *picture) void = {
 
 fn min(a: i32, b: i32) i32 = if (a<b) a else b;
 fn max(a: i32, b: i32) i32 = if (a<b) b else a;
+fn sign(x: i32) i32 = if (x < 0) -1 else if (x > 0) 1 else 0;
+fn abs(x: i32) i32 = if (x<0) -x else x;
 
 // Draws a circle onto the picture, at given position radius color
 // Clips at the boundaries of the picture to avoid overflow.
@@ -98,6 +99,23 @@ export fn circle_hollow(picture: *picture, c: pos, r: i32, color: u32) void = {
 		};
 	};
 };
+
+export fn stroke(picture: *picture, c0: pos, c1: pos, r: i32, color: u32) void = {
+	const dx = c1.0 - c0.0;
+	const dy = c1.1 - c0.1;
+	const count = (abs(dx)+abs(dy))/r;
+	const sx = dx: f64 / (count-1): f64;
+	const sy = dy: f64 / (count-1): f64;
+
+	for (let i = 0i32; i < count; i += 1) {
+		const cx = c0.0 + math::roundf64(i:f64*sx):i32;
+		const cy = c0.1 + math::roundf64(i:f64*sy):i32;
+
+		circle(picture, (cx, cy), r, color);
+	};
+};
+
+// ehh should check bounding box instead of doing all pictures maybe
 export fn perform(pictures: []picture, op: op) void = {
 	match (op) {
 	case let o: op_circle =>
@@ -109,5 +127,12 @@ export fn perform(pictures: []picture, op: op) void = {
 				(x - pic.world_pos.0, y - pic.world_pos.1): pos;
 			circle(pic, pos_within_pic, r: i32, c);
 		};
+	case let s: op_stroke =>
+		const col = s.color & 0xffffff;
+		for (const pic &.. pictures) {
+			const c0 = (s.pos0.0 - pic.world_pos.0, s.pos0.1 - pic.world_pos.1);
+			const c1 = (s.pos1.0 - pic.world_pos.0, s.pos1.1 - pic.world_pos.1);
+			stroke(pic, c0, c1, s.radius: i32, col);
+		};
 	};
 };
diff --git a/drawing/op.ha b/drawing/op.ha
index aa7fac4..82a412f 100644
--- a/drawing/op.ha
+++ b/drawing/op.ha
@@ -11,7 +11,6 @@ export type op_stroke = struct {
 	pos1: pos,
 	color: u32,
 	radius: u8,
-	count: u8,
 };
 
 export type op = (op_circle | op_stroke);
@@ -22,7 +21,6 @@ type op_type = enum u8 {
 
 export type deser_fail = !void;
 
-
 // return value must be freed... for now. ehh
 export fn ser_op(op: op) []u8 = match (op) {
 	case let opc: op_circle => yield ser_op_circle(opc);
@@ -68,8 +66,8 @@ fn deser_op_circle(bytes: []u8) (op_circle|deser_fail) = {
 	};
 };
 
-def SER_LEN_STROKE = 23;
-// type:1 pos0:8 pos1:8 color:4 radius:1 count:1
+def SER_LEN_STROKE = 22;
+// type:1 pos0:8 pos1:8 color:4 radius:1
 fn ser_op_stroke(ops: op_stroke) []u8 = {
 	let buf: []u8 = alloc([0...], SER_LEN_STROKE);
 	buf[0] = op_type::STROKE;
@@ -79,7 +77,6 @@ fn ser_op_stroke(ops: op_stroke) []u8 = {
 	ser_pos(payload[8..16], ops.pos1);
 	endian::leputu32(payload[16..20], ops.color);
 	payload[20] = ops.radius;
-	payload[21] = ops.count;
 	return buf;
 };
 fn deser_op_stroke(bytes: []u8) (op_stroke|deser_fail) = {
@@ -90,7 +87,6 @@ fn deser_op_stroke(bytes: []u8) (op_stroke|deser_fail) = {
 		pos1 = deser_pos(payload[8..16]),
 		color = endian::legetu32(payload[16..20]),
 		radius = payload[20],
-		count = payload[21],
 	};
 };