From 45f75ea7572ea46fa5247e984e0cb4b085ec66be Mon Sep 17 00:00:00 2001
From: jonathan santis <jonathan.wyss@santismail.ch>
Date: Fri, 25 Oct 2024 13:21:51 +0200
Subject: [PATCH] bresenham fix dx and dy equal 0

---
 main.zig | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/main.zig b/main.zig
index 7361f30..bb9d3fe 100644
--- a/main.zig
+++ b/main.zig
@@ -140,7 +140,7 @@ fn fillBuffer() !void {
     defer allocator.free(buffer);
 
     var vec = Vec3{
-        .a = Point{ .x = 20, .y = 20, .z = 0, .direction = .{ .x = 1, .y = 1, .z = 1 } },
+        .a = Point{ .x = 20, .y = 30, .z = 0, .direction = .{ .x = 1, .y = 1, .z = 1 } },
         .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 } },
     };
@@ -165,9 +165,8 @@ fn fillBuffer() !void {
         try triangle(buffer, w, vec);
         //_ = try bresenham(buffer, w, Point{ .x = 10, .y = 10, .z = 0 }, Point{ .x = 30, .y = 12, .z = 0 });
 
-        sleep(20000000);
-
         try out.print("\x1B[2J", .{});
+        //sleep(1000000);
 
         try triangle(buffer, w, vec);
         bounce(w, &vec.a, 'x');
@@ -185,7 +184,7 @@ fn fillBuffer() !void {
         bounce(w, &vec2.c, 'x');
         bounce(w, &vec2.c, 'y');
         try out.print("{s}", .{buffer});
-        sleep(10000000);
+        sleep(30000000);
         //_ = try stdin.readUntilDelimiterOrEof(&buf, '\n');
     }
 }
@@ -253,7 +252,7 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
                 er -= dx;
             }
         }
-    } else if (dx < dy and dy > 0 and dx > 0) {
+    } else if (dx <= dy and dy >= 0 and dx >= 0) {
         while (y <= p2.y) : (y += 1) {
             _ = try pixel(buf, w, x, y, '█');
             er += dx;
@@ -262,7 +261,7 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
                 er -= dy;
             }
         }
-    } else if (@abs(dy) < dx and dy < 0 and dx > 0) {
+    } 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;
@@ -271,7 +270,7 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
                 er -= dx;
             }
         }
-    } else if (@abs(dy) > dx and dy < 0 and dx > 0) {
+    } 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;
@@ -280,7 +279,7 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
                 er += dy;
             }
         }
-    } else if (@abs(dx) <= dy and dx < 0 and dy > 0) {
+    } 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);
@@ -289,7 +288,7 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
                 er -= dy;
             }
         }
-    } else if (@abs(dx) > dy and dy > 0 and dx < 0) {
+    } 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;
@@ -298,7 +297,7 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
                 er -= @abs(dx);
             }
         }
-    } else if (dx <= dy and dx < 0 and dy < 0) {
+    } 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);
@@ -307,7 +306,7 @@ fn bresenham(buf: []u8, w: Winsize, p1: Point, p2: Point) !void {
                 er -= @abs(dx);
             }
         }
-    } else if (dx > dy and dy < 0 and dx < 0) {
+    } 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, '█');