fixed the issue of entire Y-axis being plotted due to an overflow error

src/main.zig

@@ -17,20 +17,21 @@ pub fn main() !void {
     defer rl.closeWindow();
 
     rl.setTargetFPS(60);
-
-    // todo move away from being a loop, a static trigonometry should not be redrawn every frame
     rl.beginDrawing();
 
     rl.clearBackground(rl.Color.white);
 
-    try markAxis(allocator);
     plotGraph();
     drawAxis();
+    try markAxis(allocator);
 
     rl.endDrawing();
 
     while (!rl.windowShouldClose()) {
         rl.beginDrawing();
+        // DEBUG
+        // const pos = rl.getMousePosition();
+        // std.debug.print("x: {d} y:{}\n", .{ pos.x, pos.y });
         rl.endDrawing();
     }
 }
@@ -55,7 +56,7 @@ fn markAxis(allocator: std.mem.Allocator) !void {
     var cnt: usize = 0;
     var i: i32 = start_x;
     while (i <= SCREENWIDTH) : (i += SCALE) {
-        // get
+        // int to string
         const text = try std.fmt.bufPrintZ(&buf, "{}", .{cnt});
         cnt += 1;
         // 0 is due to us working with C-style strings
@@ -75,17 +76,30 @@ fn markAxis(allocator: std.mem.Allocator) !void {
         rl.drawText(text_back, SCREENWIDTH - i - diff - diff / 2, start_y + diff, font_size, rl.Color.black);
     }
 
+    // start at 1 as we're not drawing 0 this time
+    cnt = 1;
     i = start_y;
     while (i <= SCREENHEIGHT) : (i += SCALE) {
-        // +y
-        rl.drawCircle(start_x, @intCast(i), radius, rl.Color.black);
+        // skip 0 as it is already rendered during x scale
+        if (i == start_y) continue;
+
+        const text = try std.fmt.bufPrintZ(&buf, "{}", .{cnt});
+        cnt += 1;
+        var text_back = try allocator.allocSentinel(u8, text.len + 1, 0);
+        defer allocator.free(text_back);
+        @memcpy(text_back[0..1], "-");
+        @memcpy(text_back[1..], text);
 
         // -y
+        rl.drawCircle(start_x, @intCast(i), radius, rl.Color.black);
+        rl.drawText(text_back, start_x + diff, @as(i32, @intCast(i)) - diff, font_size, rl.Color.black);
+
+        // +y
         rl.drawCircle(start_x, SCREENHEIGHT - i, radius, rl.Color.black);
+        rl.drawText(text, start_x + diff, SCREENHEIGHT - i - diff, font_size, rl.Color.black);
     }
 }
 
-// todo in the future we will do calculations only once and just repeat displaying
 fn plotGraph() void {
     const diff: f32 = 0.01;
     const thickness = 2.5;
@@ -94,36 +108,36 @@ fn plotGraph() void {
     while (x_value <= SCREENWIDTH) : (x_value += diff) {
         const cur_pos = adjustForGridSystem(rl.Vector2{
             .x = x_value,
-            .y = getY(x_value),
+            .y = getY(x_value) catch {
+                continue;
+            },
         });
 
+        // this is to ensure the value doesn't wrap around to zero causing the entire Y-axis to be graphed
+        if (cur_pos.y > SCREENHEIGHT) {
+            continue;
+        }
+
         const next_pos = adjustForGridSystem(rl.Vector2{
             .x = x_value + diff,
-            .y = getY(x_value + diff),
+            .y = getY(x_value + diff) catch {
+                continue;
+            },
         });
 
-        // test
-        if (cur_pos.x == 0 or next_pos.x == 0) {
-            continue;
-        }
-
         rl.drawLineEx(cur_pos, next_pos, thickness, rl.Color.dark_blue);
     }
 }
 
 // f(x)
-fn getY(x: f32) f32 {
-    const min_threshold = 1e-3;
-    const a = x / 10;
-    var b: f32 = 1.0;
-    if (b == 0) b = a / min_threshold;
-
-    return a / b;
+fn getY(x: f32) !f32 {
+    return math.calculate(x, -3, .Power);
 }
 
 fn adjustForGridSystem(input_vector: rl.Vector2) rl.Vector2 {
     // std.debug.print("{d} => {d}\n", .{ input_vector.x, input_vector.x * SCALE });
     const new_vector = rl.Vector2{
+        // we add screenwidth because in traditional gui libraries the grid starts in top left and not in the center like the coordinate system
         .x = input_vector.x * SCALE + SCREENWIDTH / 2,
         .y = -input_vector.y * SCALE + SCREENHEIGHT / 2, // minus is there because y works the opposite in gui libraries than in coordination system
     };

src/math.zig

@@ -1,4 +1,36 @@
-pub fn abs(a: f32) f32 {
+const std = @import("std");
+
+pub const MathOperation = enum {
+    Division,
+    Power,
+    Root,
+};
+
+pub fn calculate(first: f32, second: f32, op: MathOperation) !f32 {
+    switch (op) {
+        .Division => {
+            if (second == 0) {
+                return error.InvalidParam;
+            }
+            return first / second;
+        },
+        .Power => {
+            if (first == 0) std.debug.print("KOK", .{});
+            if (first == 0 and second < 0) {
+                return error.InvalidParam;
+            }
+            return pow(first, @intFromFloat(second));
+        },
+        .Root => {
+            if (first < 0 or second < 0) {
+                return error.InvalidParam;
+            }
+            return std.math.sqrt(second);
+        },
+    }
+}
+
+fn abs(a: f32) f32 {
     if (a < 0) {
         return -a;
     }
@@ -6,7 +38,7 @@ pub fn abs(a: f32) f32 {
     return a;
 }
 
-pub fn pow(a: f32, b: i32) f32 {
+fn pow(a: f32, b: i32) f32 {
     var res: f32 = 1.0;
     var n: usize = undefined;
     var f: f32 = undefined;