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Add bresenham variants

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jonathan santis 2024-10-23 13:51:33 +02:00
parent 4987faed56
commit f834d31d46
1 changed files with 38 additions and 23 deletions
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47
main.zig
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@ -136,7 +136,11 @@ fn fillBuffer() !void {
}; };
_ = vec; _ = vec;
//triangle(vec); //triangle(vec);
_ = try bresenham(buffer, w, Point{ .x = 10, .y = 40, .z = 0 }, Point{ .x = 30, .y = 10, .z = 0 }); _ = try bresenham(buffer, w, Point{ .x = 10, .y = 10, .z = 0 }, Point{ .x = 30, .y = 12, .z = 0 });
_ = try bresenham(buffer, w, Point{ .x = 10, .y = 10, .z = 0 }, Point{ .x = 30, .y = 28, .z = 0 });
_ = try bresenham(buffer, w, Point{ .x = 10, .y = 10, .z = 0 }, Point{ .x = 30, .y = 30, .z = 0 });
_ = try bresenham(buffer, w, Point{ .x = 10, .y = 10, .z = 0 }, Point{ .x = 30, .y = 40, .z = 0 });
_ = try bresenham(buffer, w, Point{ .x = 30, .y = 30, .z = 0 }, Point{ .x = 60, .y = 10, .z = 0 });
try file.writeAll(buffer); try file.writeAll(buffer);
} }
fn pixel(buffer: []u8, w: Winsize, x: i64, y: i64, symbol: u21) !void { fn pixel(buffer: []u8, w: Winsize, x: i64, y: i64, symbol: u21) !void {
@ -152,26 +156,16 @@ fn pixel(buffer: []u8, w: Winsize, x: i64, y: i64, symbol: u21) !void {
} }
} }
fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void { fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
const x1: i32 = p1.x; var x: i32 = p1.x;
const y1: i32 = p1.y; var y: i32 = p1.y;
var x: i32 = 0; //var x: i32 = 0;
var y: i32 = 0; //var y: i32 = 0;
const dx = (p2.x - p1.x); const dx = (p2.x - p1.x);
print("p2: {} - {},{}\n", .{ p2.y, p1.y, p2.y - p1.y }); print("p2: {} - {},{}\n", .{ p2.y, p1.y, p2.y - p1.y });
const dy: i64 = (p2.y - p1.y); const dy: i64 = (p2.y - p1.y);
//const slope = dx/dy; //const slope = dx/dy;
var er: i64 = 0; var er: i64 = 0;
if (dx >= dy and dy > 0) {
if (dy > 0 and dy <= dx) {
x = x1;
y = y1;
}
if (dy < 0 and @abs(dy) > dx) {
print("octant2\n", .{});
x = y1;
y = x1;
}
while (x <= p2.x) : (x += 1) { while (x <= p2.x) : (x += 1) {
print("[bresenham]x:{},y:{},er:{},dx:{},dy:{}\n", .{ x, y, er, dx, dy }); print("[bresenham]x:{},y:{},er:{},dx:{},dy:{}\n", .{ x, y, er, dx, dy });
_ = try pixel(buf, w, x, y, '.'); _ = try pixel(buf, w, x, y, '.');
@ -181,6 +175,27 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
er -= dx; er -= dx;
} }
} }
} else if (dx < dy and dy > 0) {
while (y <= p2.y) : (y += 1) {
print("[bresenham2]x:{},y:{},er:{},dx:{},dy:{}\n", .{ x, y, er, dx, dy });
_ = try pixel(buf, w, x, y, ',');
er += dx;
if (2 * er >= dy) {
x += 1;
er -= dy;
}
}
} else if (@abs(dy) < dx and dy < 0) {
while (x <= p2.x) : (x += 1) {
print("[bresenham3]x:{},y:{},er:{},dx:{},dy:{}\n", .{ x, y, er, dx, dy });
_ = try pixel(buf, w, x, y, 'x');
er -= dy;
if (2 * er >= dx) {
y -= 1;
er -= dx;
}
}
}
} }
//fn triangle(vec: Vec3) void { //fn triangle(vec: Vec3) void {