GUI: Box drawing

src/Game.zig

@@ -15,6 +15,7 @@ const Chunk = @import("assets/Chunk.zig");
 const Chunks = @import("Chunks.zig");
 const CommandBuffer = @import("engine/CommandBuffer.zig");
 const Engine = @import("engine/Engine.zig");
+const Gui = @import("Gui.zig");
 const Iterator2 = math.Iterator2;
 const Materials = @import("assets/Materials.zig");
 const Player = @import("Player.zig");
@@ -51,6 +52,7 @@ materials: Materials,
 textures: Textures,
 chunks: Chunks,
 skybox: Skybox,
+gui: Gui,
 
 player: Player,
 
@@ -164,7 +166,7 @@ pub fn init(allocator: std.mem.Allocator, io: std.Io, engine: *Engine, swapchain
         },
     });
     errdefer engine.destroyPipelineLayout(pipeline_layout);
-    engine.setObjectName(pipeline_layout, "PL", .{});
+    engine.setObjectName(pipeline_layout, "PL Main", .{});
 
     const vertex_shader = try engine.createShaderModule(.{ .code = &shaders.main_vert_spv });
     defer engine.destroyShaderModule(vertex_shader);
@@ -403,7 +405,7 @@ pub fn init(allocator: std.mem.Allocator, io: std.Io, engine: *Engine, swapchain
         .subpass = 0,
     });
     errdefer engine.destroyPipeline(pipeline);
-    engine.setObjectName(pipeline, "P", .{});
+    engine.setObjectName(pipeline, "P Main", .{});
 
     const descriptor_pool = try engine.createDescriptorPool(.{
         .flags = .{
@@ -430,7 +432,7 @@ pub fn init(allocator: std.mem.Allocator, io: std.Io, engine: *Engine, swapchain
         },
     });
     errdefer engine.destroyDescriptorPool(descriptor_pool);
-    engine.setObjectName(descriptor_pool, "DP", .{});
+    engine.setObjectName(descriptor_pool, "DP Main", .{});
 
     const global_descriptor_set = try engine.allocateDescriptorSet(.{
         .descriptor_pool = descriptor_pool,
@@ -645,6 +647,14 @@ pub fn init(allocator: std.mem.Allocator, io: std.Io, engine: *Engine, swapchain
     );
     errdefer skybox.deinit(engine);
 
+    var gui = try Gui.init(
+        allocator,
+        engine,
+        global_uniforms.buffer,
+        swapchain.render_pass,
+    );
+    errdefer gui.deinit(engine, allocator);
+
     return .{
         .allocator = allocator,
         .io = io,
@@ -674,6 +684,7 @@ pub fn init(allocator: std.mem.Allocator, io: std.Io, engine: *Engine, swapchain
         .textures = textures,
         .chunks = .{ .chunks = chunks },
         .skybox = skybox,
+        .gui = gui,
 
         .player = .init(player_position_sv, 0, 0),
     };
@@ -692,6 +703,7 @@ pub fn deinit(self: *Game) void {
 
     self.chunks.deinit(self.engine, self.descriptor_pool, self.allocator);
     self.skybox.deinit(self.engine);
+    self.gui.deinit(self.engine, self.allocator);
 
     self.global_uniforms.deinit(self.engine);
     self.global_uniforms_staging_buffer.deinit(self.engine);
@@ -718,8 +730,36 @@ pub fn deinit(self: *Game) void {
 }
 
 pub fn update(self: *Game, dt: f32) void {
+    self.gui.beginFrame();
     self.player.update(dt, &self.chunks);
 
+    const extent = self.swapchain.extent;
+    const framebuffer_size = vm.Vector2.init(
+        @floatFromInt(extent.width),
+        @floatFromInt(extent.height),
+    );
+
+    const crosshair_half_extent_px = 8;
+    const crosshair_half_width_px = 1;
+
+    self.gui.pushBox(.{
+        .background_color = .init(1, 1, 1, 0.5),
+        .border_color = .init(0, 0, 0, 1),
+        .position_sspx = framebuffer_size.mulScalar(0.5).add(.init(-crosshair_half_extent_px, -crosshair_half_width_px)),
+        .size_px = .init(2.0 * crosshair_half_extent_px, 2.0 * crosshair_half_width_px),
+        .border_width_px = 0,
+        .border_radius_px = 0,
+    });
+
+    self.gui.pushBox(.{
+        .background_color = .init(1, 1, 1, 0.5),
+        .border_color = .init(0, 0, 0, 1),
+        .position_sspx = framebuffer_size.mulScalar(0.5).add(.init(-crosshair_half_width_px, -crosshair_half_extent_px)),
+        .size_px = .init(2.0 * crosshair_half_width_px, 2.0 * crosshair_half_extent_px),
+        .border_width_px = 0,
+        .border_radius_px = 0,
+    });
+
     self.render() catch |err| {
         std.log.err("Failed to render: {s}", .{@errorName(err)});
         @panic("Frame update failed");
@@ -807,11 +847,20 @@ fn render(self: *Game) !void {
     );
     // zig fmt: on
 
+    // zig fmt: off
+    const matrix_sspx_to_cs = vm.Matrix3x2.init(
+        2.0 / framebuffer_size.x,  0,
+        0,                         2.0 / framebuffer_size.y,
+        -1,                       -1,
+    );
+    // zig fmt: on
+
     const ambient_light = vm.Vector3.init(0.01, 0.01, 0.01);
 
     const global_uniforms_data: shaders.GlobalUniforms = .{
         .matrixWStoVS = matrix_ws_to_vs,
         .matrixVStoCS = matrix_vs_to_cs,
+        .matrixSSPXtoCS = matrix_sspx_to_cs,
         .ambientLight = ambient_light,
     };
 
@@ -887,6 +936,8 @@ fn render(self: *Game) !void {
             },
         });
 
+        // --- SUBPASS 0 (MAIN) ---
+
         command_buffer.bindPipeline(.graphics, self.pipeline);
         try command_buffer.bindVertexBuffers(0, &.{
             .{
@@ -902,8 +953,13 @@ fn render(self: *Game) !void {
             chunk.draw(self.pipeline_layout, command_buffer);
         }
 
-        try self.skybox.bind(command_buffer, extent);
-        self.skybox.draw(command_buffer);
+        try self.skybox.draw(command_buffer);
+
+        // --- SUBPASS 1 (GUI) ---
+
+        command_buffer.nextSubpass(.@"inline");
+
+        try self.gui.draw(self.engine, command_buffer);
     }
     try command_buffer.endCommandBuffer();