mach: wasm: initial implementation of Core, added js polyfill and

application html

src/wasm.zig

@@ -4,17 +4,42 @@ const Engine = @import("Engine.zig");
 const structs = @import("structs.zig");
 const enums = @import("enums.zig");
 
-const js = struct {};
+const js = struct {
+    extern fn machCanvasInit(width: u32, height: u32, selector_id: *u8) CanvasId;
+    extern fn machCanvasDeinit(canvas: CanvasId) void;
+    extern fn machCanvasSetTitle(canvas: CanvasId, title: [*]const u8, len: u32) void;
+    extern fn machCanvasSetSize(canvas: CanvasId, width: u32, height: u32) void;
+    extern fn machCanvasGetWidth(canvas: CanvasId) u32;
+    extern fn machCanvasGetHeight(canvas: CanvasId) u32;
+};
+
+pub const CanvasId = u32;
 
 pub const CoreWasm = struct {
-    pub fn init(_: std.mem.Allocator, _: *Engine) !CoreWasm {
-        return CoreWasm{};
+    id: CanvasId,
+    selector_id: []const u8,
+
+    pub fn init(allocator: std.mem.Allocator, eng: *Engine) !CoreWasm {
+        const options = eng.options;
+        var selector = [1]u8{0} ** 15;
+        const id = js.machCanvasInit(options.width, options.height, &selector[0]);
+
+        const title = std.mem.span(options.title);
+        js.machCanvasSetTitle(id, title.ptr, title.len);
+
+        return CoreWasm{
+            .id = id,
+            .selector_id = try allocator.dupe(u8, selector[0 .. selector.len - @as(u32, if (selector[selector.len - 1] == 0) 1 else 0)]),
+        };
     }
 
     pub fn setShouldClose(_: *CoreWasm, _: bool) void {}
 
-    pub fn getFramebufferSize(_: *CoreWasm) !structs.Size {
-        return structs.Size{ .width = 0, .height = 0 };
+    pub fn getFramebufferSize(core: *CoreWasm) !structs.Size {
+        return structs.Size{
+            .width = js.machCanvasGetWidth(core.id),
+            .height = js.machCanvasGetHeight(core.id),
+        };
     }
 
     pub fn setSizeLimits(_: *CoreWasm, _: structs.SizeOptional, _: structs.SizeOptional) !void {}