Restructure into different files

primitives.zig

@@ -1,3 +1,7 @@
+const std = @import("std");
+const term = @import("term.zig");
+const Winsize = term.Winsize;
+
 pub const Direction = struct {
     x: i8 = 1,
     y: i8 = 1,
@@ -29,4 +33,101 @@ pub var vec2 = Vec3{
     .b = Point{ .x = 50, .y = 30, .z = 0, .direction = .{ .x = 1, .y = 1, .z = 1 } },
     .c = Point{ .x = 30, .y = 1, .z = 0, .direction = .{ .x = 1, .y = 1, .z = 1 } },
 };
-pub var vec3: [10]Vec3 = undefined;
+pub var obj: [10]Vec3 = undefined;
+
+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);
+}