zig-learn/primitives.zig
jonathan santis acb8e8163d day end
2024-10-30 14:56:09 +01:00

132 lines
3.8 KiB
Zig

const std = @import("std");
const term = @import("term.zig");
const Winsize = term.Winsize;
pub const Direction = struct {
x: i8 = 1,
y: i8 = 1,
z: i8 = 1,
};
pub const Point = struct {
x: i32 = 0,
y: i32 = 0,
z: i32 = 0,
direction: Direction, //for movement state
};
pub const Vec3 = struct {
a: Point = .{ .x = 0, .y = 0, .z = 0, .direction = .{ .x = 0, .y = 0, .z = 0 } },
b: Point = .{ .x = 0, .y = 0, .z = 0, .direction = .{ .x = 0, .y = 0, .z = 0 } },
c: Point = .{ .x = 0, .y = 0, .z = 0, .direction = .{ .x = 0, .y = 0, .z = 0 } },
};
pub const Triangle = struct {
bufa: *i32,
bufb: *i32,
bufc: *i32,
};
pub const Polygon = struct{
const Node = struct{point:Point,*Node};
head: *Node;
length: u32;
pub fn new() Node {
return Node
pub fn pixel(buffer: []u8, w: Winsize, x: i64, y: i64, symbol: u21) !void {
const i: usize = @intCast(4 * (x + y * w.ws_col));
if (i < buffer.len) { //-1 ??
const slice = buffer[i .. i + 4];
_ = try std.unicode.utf8Encode(symbol, slice);
//TODO: check length, set not used bytes to zero
} else {
//print("Error illegal memory access\n", .{});
}
}
pub fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
var x: i32 = p1.x;
var y: i32 = p1.y;
const dx = (p2.x - p1.x);
const dy = (p2.y - p1.y);
var er: i64 = 0;
if (dx >= dy and dy > 0 and dx > 0) {
while (x <= p2.x) : (x += 1) {
_ = try pixel(buf, w, x, y, '█');
er += dy;
if (2 * er >= dx) {
y += 1;
er -= dx;
}
}
} else if (dx <= dy and dy >= 0 and dx >= 0) {
while (y <= p2.y) : (y += 1) {
_ = try pixel(buf, w, x, y, '█');
er += dx;
if (2 * er >= dy) {
x += 1;
er -= dy;
}
}
} else if (@abs(dy) <= dx and dy <= 0 and dx >= 0) {
while (x <= p2.x) : (x += 1) {
_ = try pixel(buf, w, x, y, '█');
er -= dy;
if (2 * er >= dx) {
y -= 1;
er -= dx;
}
}
} else if (@abs(dy) >= dx and dy <= 0 and dx >= 0) {
while (y >= p2.y) : (y -= 1) {
_ = try pixel(buf, w, x, y, '█');
er += dx;
if (2 * er >= dy) {
x += 1;
er += dy;
}
}
} else if (@abs(dx) <= dy and dx <= 0 and dy >= 0) {
while (y <= p2.y) : (y += 1) {
_ = try pixel(buf, w, x, y, '█');
er += @abs(dx);
if (2 * er >= dy) {
x -= 1;
er -= dy;
}
}
} else if (@abs(dx) >= dy and dy >= 0 and dx <= 0) {
while (x >= p2.x) : (x -= 1) {
_ = try pixel(buf, w, x, y, '█');
er += dy;
if (2 * er >= @abs(dx)) {
y += 1;
er -= @abs(dx);
}
}
} else if (dx <= dy and dx <= 0 and dy <= 0) {
while (x >= p2.x) : (x -= 1) {
_ = try pixel(buf, w, x, y, '█');
er += @abs(dy);
if (2 * er >= @abs(dx)) {
y -= 1;
er -= @abs(dx);
}
}
} else if (dx >= dy and dy <= 0 and dx <= 0) {
while (y >= p2.y) : (y -= 1) {
//print("x:{},y:{},er:{},dx:{},dy:{}\n", .{ x, y, er, dx, dy });
_ = try pixel(buf, w, x, y, '█');
er += @abs(dx);
if (2 * er >= @abs(dx)) {
x -= 1;
er -= @abs(dy);
}
}
}
}
pub fn triangle(buffer: []u8, w: Winsize, vector: Vec3) !void {
try bresenham(buffer, w, vector.a, vector.b);
try bresenham(buffer, w, vector.b, vector.c);
try bresenham(buffer, w, vector.c, vector.a);
}