From d712a7d8d4e48a8791097be2aa4959950a5de84a Mon Sep 17 00:00:00 2001
From: jonathan santis <jonathan.wyss@santismail.ch>
Date: Thu, 24 Oct 2024 08:57:37 +0200
Subject: [PATCH] oct 5 and 6

---
 main.zig | 39 +++++++++++++++++++++++++++++----------
 1 file changed, 29 insertions(+), 10 deletions(-)

diff --git a/main.zig b/main.zig
index 705a949..69775b7 100644
--- a/main.zig
+++ b/main.zig
@@ -139,19 +139,18 @@ fn fillBuffer() !void {
     _ = 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 = 10, .y = 10, .z = 0 }, Point{ .x = 30, .y = 39, .z = 0 });
     _ = try bresenham(buffer, w, Point{ .x = 30, .y = 30, .z = 0 }, Point{ .x = 60, .y = 10, .z = 0 });
     _ = try bresenham(buffer, w, Point{ .x = 60, .y = 30, .z = 0 }, Point{ .x = 70, .y = 5, .z = 0 });
+    _ = try bresenham(buffer, w, Point{ .x = 100, .y = 20, .z = 0 }, Point{ .x = 30, .y = 30, .z = 0 });
+    _ = try bresenham(buffer, w, Point{ .x = 100, .y = 10, .z = 0 }, Point{ .x = 90, .y = 40, .z = 0 });
     try file.writeAll(buffer);
 }
 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) {
         const slice = buffer[i .. i + 4];
-        print("slice:{u}\n", .{slice});
         _ = try std.unicode.utf8Encode(symbol, slice);
-        print("slice after:{u}\n", .{slice});
-        print("cols{}\ni: {}\n", .{ w.ws_col, i });
     } else {
         print("Error illegal memory access\n", .{});
     }
@@ -166,7 +165,7 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
     const dy: i64 = (p2.y - p1.y);
     //const slope = dx/dy;
     var er: i64 = 0;
-    if (dx >= dy and dy > 0) {
+    if (dx >= dy and dy > 0 and dx > 0) {
         while (x <= p2.x) : (x += 1) {
             print("[bresenham]x:{},y:{},er:{},dx:{},dy:{}\n", .{ x, y, er, dx, dy });
             _ = try pixel(buf, w, x, y, '.');
@@ -176,7 +175,7 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
                 er -= dx;
             }
         }
-    } else if (dx < dy and dy > 0) {
+    } else if (dx < dy and dy > 0 and dx > 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, ',');
@@ -186,26 +185,46 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
                 er -= dy;
             }
         }
-    } else if (@abs(dy) < dx and dy < 0) {
+    } else if (@abs(dy) < dx and dy < 0 and dx > 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');
+            _ = try pixel(buf, w, x, y, '🡇');
             er -= dy;
             if (2 * er >= dx) {
                 y -= 1;
                 er -= dx;
             }
         }
-    } else if (@abs(dy) > dx and dy < 0) {
+    } else if (@abs(dy) > dx and dy < 0 and dx > 0) {
         while (y >= p2.y) : (y -= 1) {
             print("[bresenham4]x:{},y:{},er:{},dx:{},dy:{}\n", .{ x, y, er, dx, dy });
-            _ = try pixel(buf, w, x, y, '4');
+            _ = 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) {
+            print("[bresenham5]x:{},y:{},er:{},dx:{},dy:{}\n", .{ x, y, er, dx, dy });
+            _ = try pixel(buf, w, x, y, '5');
+            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) {
+            print("[bresenham6]x:{},y:{},er:{},dx:{},dy:{}\n", .{ x, y, er, dx, dy });
+            _ = try pixel(buf, w, x, y, '6');
+            er += dy;
+            if (2 * er >= @abs(dx)) {
+                y += 1;
+                er -= @abs(dx);
+            }
+        }
     }
 }