rename & scale implementation

build.zig

@@ -4,7 +4,7 @@ const rlz = @import("raylib-zig");
 pub fn build(b: *std.Build) !void {
     const target = b.standardTargetOptions(.{});
     const optimize = b.standardOptimizeOption(.{});
-    
+
     const raylib_dep = b.dependency("raylib-zig", .{
         .target = target,
         .optimize = optimize,
@@ -15,7 +15,7 @@ pub fn build(b: *std.Build) !void {
 
     //web exports are completely separate
     if (target.query.os_tag == .emscripten) {
-        const exe_lib = try rlz.emcc.compileForEmscripten(b, "integral-display-calculation", "src/main.zig", target, optimize);
+        const exe_lib = try rlz.emcc.compileForEmscripten(b, "koordinatni-sistem", "src/main.zig", target, optimize);
 
         exe_lib.linkLibrary(raylib_artifact);
         exe_lib.root_module.addImport("raylib", raylib);
@@ -29,18 +29,18 @@ pub fn build(b: *std.Build) !void {
         b.getInstallStep().dependOn(&link_step.step);
         const run_step = try rlz.emcc.emscriptenRunStep(b);
         run_step.step.dependOn(&link_step.step);
-        const run_option = b.step("run", "Run integral-display-calculation");
+        const run_option = b.step("run", "Run koordinatni-sistem");
         run_option.dependOn(&run_step.step);
         return;
     }
 
-    const exe = b.addExecutable(.{ .name = "integral-display-calculation", .root_source_file = b.path("src/main.zig"), .optimize = optimize, .target = target });
+    const exe = b.addExecutable(.{ .name = "koordinatni-sistem", .root_source_file = b.path("src/main.zig"), .optimize = optimize, .target = target });
 
     exe.linkLibrary(raylib_artifact);
     exe.root_module.addImport("raylib", raylib);
 
     const run_cmd = b.addRunArtifact(exe);
-    const run_step = b.step("run", "Run integral-display-calculation");
+    const run_step = b.step("run", "Run koordinatni-sistem");
     run_step.dependOn(&run_cmd.step);
 
     b.installArtifact(exe);

build.zig.zon

@@ -1,5 +1,5 @@
 .{
-    .name = "integral-display-calculation",
+    .name = "koordinatni-sistem",
     .version = "0.0.1",
     .dependencies = .{
         .@"raylib-zig" = .{

src/main.zig

@@ -4,22 +4,34 @@ const math = @import("math.zig");
 
 const SCREENWIDTH = 1920;
 const SCREENHEIGHT = 1080;
+const SCALE = 50;
 
 pub fn main() !void {
+    // std.debug.print("{d}\n", .{SCREENWIDTH / 2});
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer _ = gpa.deinit();
+    const allocator = gpa.allocator();
+
     rl.setConfigFlags(.{ .msaa_4x_hint = true });
     rl.initWindow(SCREENWIDTH, SCREENHEIGHT, "Koordinatni sistem");
     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();
+
+    rl.endDrawing();
+
     while (!rl.windowShouldClose()) {
         rl.beginDrawing();
-        defer rl.endDrawing();
-
-        rl.clearBackground(rl.Color.white);
-        drawAxis();
-        // markAxis();
-        plotGraph(0.01);
+        rl.endDrawing();
     }
 }
 
@@ -32,9 +44,50 @@ fn drawAxis() void {
     rl.drawLine(endx_on_ordinat, 0, endx_on_ordinat, SCREENHEIGHT, rl.Color.black);
 }
 
+fn markAxis(allocator: std.mem.Allocator) !void {
+    const diff = 10;
+    const font_size = 20;
+    const start_x = SCREENWIDTH / 2;
+    const start_y = SCREENHEIGHT / 2;
+    const radius = SCALE / 15;
+    var buf: [20]u8 = undefined;
+
+    var cnt: usize = 0;
+    var i: i32 = start_x;
+    while (i <= SCREENWIDTH) : (i += SCALE) {
+        // get
+        const text = try std.fmt.bufPrintZ(&buf, "{}", .{cnt});
+        cnt += 1;
+        // 0 is due to us working with C-style strings
+        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);
+
+        // +x
+        rl.drawCircle(@intCast(i), start_y, radius, rl.Color.black);
+        rl.drawText(text, @as(i32, @intCast(i)) - diff / 2, start_y + diff, font_size, rl.Color.black);
+
+        if (i == start_x) continue; // prevent 0 from being written/drawn twice
+
+        // -x
+        rl.drawCircle(SCREENWIDTH - i, start_y, radius, rl.Color.black);
+        rl.drawText(text_back, SCREENWIDTH - i - diff - diff / 2, start_y + diff, font_size, rl.Color.black);
+    }
+
+    i = start_y;
+    while (i <= SCREENHEIGHT) : (i += SCALE) {
+        // +y
+        rl.drawCircle(start_x, @intCast(i), radius, rl.Color.black);
+
+        // -y
+        rl.drawCircle(start_x, SCREENHEIGHT - i, radius, rl.Color.black);
+    }
+}
+
 // todo in the future we will do calculations only once and just repeat displaying
-fn plotGraph(diff: f32) void {
-    // diff is currently 0.01
+fn plotGraph() void {
+    const diff: f32 = 0.01;
     const thickness = 2.5;
     var x_value: f32 = -SCREENWIDTH / 2;
 
@@ -49,20 +102,30 @@ fn plotGraph(diff: f32) void {
             .y = getY(x_value + diff),
         });
 
+        // 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 a = math.abs(x) - 2;
-    const b = 1;
-    return @divTrunc(a, b);
+    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 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{
-        .x = input_vector.x + SCREENWIDTH / 2,
-        .y = -input_vector.y + SCREENHEIGHT / 2,
+        .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
     };
 
     return new_vector;