Implement CRT shader effect support

debug/crt.frag

@@ -0,0 +1,52 @@
+#version 430
+
+layout (binding = 0) uniform sampler2D sprite;
+
+layout (location = 0) in vec4 color;
+layout (location = 1) in vec2 uv;
+
+layout (location = 0) out vec4 texel;
+
+layout (binding = 0) uniform Effect {
+	float screen_width;
+	float screen_height;
+	float time;
+};
+
+vec3 scanline(vec2 coord, vec3 screen)
+{
+	screen.rgb -= sin((coord.y + (time * 29.0))) * 0.02;
+	return screen;
+}
+
+vec2 crt(vec2 coord, float bend)
+{
+	// put in symmetrical coords
+	coord = (coord - 0.5) * 2.0;
+
+	coord *= 1.0;
+
+	// deform coords
+	coord.x *= 1.0 + pow((abs(coord.y) / bend), 2.0);
+	coord.y *= 1.0 + pow((abs(coord.x) / bend), 2.0);
+
+	// transform back to 0.0 - 1.0 space
+	coord  = (coord / 2.0) + 0.5;
+
+	return coord;
+}
+
+void main()
+{
+	vec2 crtCoords = crt(uv, 4.8);
+
+	// Split the color channels
+	texel.rgb = texture(sprite, crtCoords).rgb;
+	texel.a = 1;
+
+	// HACK: this bend produces a shitty moire pattern.
+	// Up the bend for the scanline
+	vec2 screenSpace = crtCoords * vec2(screen_width, screen_height);
+	texel.rgb = scanline(screenSpace, texel.rgb);
+}
+

src/main.zig

@@ -9,11 +9,20 @@ const ChromaticAberration = extern struct {
 	padding: [12]u8 = undefined,
 };
 
+const CRT = extern struct {
+	width: f32,
+	height: f32,
+	time: f32,
+	padding: [4]u8 = undefined,
+};
+
 const Actors = struct {
 	instances: coral.stack.Sequential(@Vector(2, f32)) = .{.allocator = coral.heap.allocator},
 	body_texture: ona.gfx.Texture = .default,
 	render_texture: ona.gfx.Texture = .default,
 	ca_effect: ona.gfx.Effect = .default,
+	crt_effect: ona.gfx.Effect = .default,
+	staging_texture: ona.gfx.Texture = .default,
 };
 
 const Player = struct {
@@ -44,6 +53,7 @@ fn load(config: ona.Write(ona.gfx.Config), actors: ona.Write(Actors), assets: on
 	});
 
 	actors.res.ca_effect = try assets.res.load_effect_file(coral.files.bundle, "./ca.frag.spv");
+	actors.res.crt_effect = try assets.res.load_effect_file(coral.files.bundle, "./crt.frag.spv");
 
 	try actors.res.instances.push_grow(.{0, 0});
 }
@@ -52,22 +62,46 @@ fn exit(actors: ona.Write(Actors)) void {
 	actors.res.instances.deinit();
 }
 
-fn render(commands: ona.gfx.Commands, actors: ona.Write(Actors)) !void {
-	try commands.set_effect(actors.res.ca_effect, ChromaticAberration{
-		.effect_magnitude = 15.0,
+fn render(commands: ona.gfx.Commands, actors: ona.Write(Actors), app: ona.Read(ona.App)) !void {
+	try commands.set_target(.{
+		.texture = actors.res.render_texture,
+		.clear_color = ona.gfx.colors.black,
+		.clear_depth = 0,
+		.clear_stencil = 0,
 	});
 
-	for (actors.res.instances.values) |instance| {
-		try commands.draw_texture(.{
-			.texture = actors.res.body_texture,
+	try commands.draw_texture(.{
+		.texture = .default,
 
-			.transform = .{
-				.origin = instance,
-				.xbasis = .{64, 0},
-				.ybasis = .{0, 64},
-			},
-		});
-	}
+		.transform = .{
+			.origin = .{1280 / 2, 720 / 2},
+			.xbasis = .{1280, 0},
+			.ybasis = .{0, 720},
+		},
+	});
+
+	try commands.set_effect(actors.res.crt_effect, CRT{
+		.width = 1280,
+		.height = 720,
+		.time = @floatCast(app.res.elapsed_time),
+	});
+
+	try commands.set_target(.{
+		.texture = .backbuffer,
+		.clear_color = null,
+		.clear_depth = null,
+		.clear_stencil = null,
+	});
+
+	try commands.draw_texture(.{
+		.texture = actors.res.render_texture,
+
+		.transform = .{
+			.origin = .{1280 / 2, 720 / 2},
+			.xbasis = .{1280, 0},
+			.ybasis = .{0, 720},
+		},
+	});
 }
 
 fn update(player: ona.Read(Player), actors: ona.Write(Actors), mapping: ona.Read(ona.act.Mapping)) !void {

src/ona/App.zig

@@ -4,6 +4,7 @@ const flow = @import("flow");
 
 events: *const Events,
 target_frame_time: f64,
+elapsed_time: f64,
 is_running: bool,
 
 pub const Events = struct {

src/ona/gfx/handles.zig

@@ -17,33 +17,40 @@ fn Handle(comptime HandleDesc: type) type {
 	};
 }
 
-pub const Texture = Handle(struct {
-	format: Format,
-	access: Access,
+pub const Texture = enum (u32) {
+	default,
+	backbuffer,
+	_,
 
-	pub const Access = union (enum) {
-		static: Static,
-		render: Render,
+	pub const Desc = struct {
+		format: Format,
+		access: Access,
 
-		pub const Static = struct {
-			width: u16,
-			data: []const coral.io.Byte,
-		};
+		pub const Access = union (enum) {
+			static: Static,
+			render: Render,
 
-		pub const Render = struct {
-			width: u16,
-			height: u16,
-		};
-	};
-
-	pub const Format = enum {
-		rgba8,
-		bgra8,
-
-		pub fn byte_size(self: Format) usize {
-			return switch (self) {
-				.rgba8, .bgra8 => 4,
+			pub const Static = struct {
+				width: u16,
+				data: []const coral.io.Byte,
 			};
-		}
+
+			pub const Render = struct {
+				width: u16,
+				height: u16,
+			};
+		};
+
+		pub const Format = enum {
+			rgba8,
+			bgra8,
+
+			pub fn byte_size(self: Format) usize {
+				return switch (self) {
+					.rgba8, .bgra8 => 4,
+				};
+			}
+		};
 	};
-});
+};
+

src/ona/gfx/rendering.zig

@@ -30,7 +30,7 @@ pub const Command = union (enum) {
 	};
 
 	pub const SetTarget = struct {
-		texture: ?handles.Texture = null,
+		texture: handles.Texture,
 		clear_color: ?lina.Color,
 		clear_depth: ?f32,
 		clear_stencil: ?u8,
@@ -135,7 +135,7 @@ const Frame = struct {
 	drawn_count: usize = 0,
 	flushed_count: usize = 0,
 	current_source_texture: handles.Texture = .default,
-	current_target_texture: ?handles.Texture = null,
+	current_target_texture: handles.Texture = .backbuffer,
 	current_effect: handles.Effect = .default,
 
 	const DrawTexture = extern struct {
@@ -185,42 +185,39 @@ const Frame = struct {
 
 		bindings.vertex_buffers[vertex_indices.mesh] = quad_vertex_buffer;
 
-		switch (pools.textures.get(@intFromEnum(self.current_source_texture)).?.access) {
+		switch (pools.get_texture(self.current_source_texture).?.access) {
 			.render => |render| {
 				bindings.fs.images[0] = render.color_image;
-				bindings.fs.samplers[0] = render.sampler;
+				bindings.fs.samplers[0] = default_sampler;
 			},
 
 			.static => |static| {
 				bindings.fs.images[0] = static.image;
-				bindings.fs.samplers[0] = static.sampler;
+				bindings.fs.samplers[0] = default_sampler;
+			},
+
+			.empty => {
+				@panic("Cannot render empty textures");
 			},
 		}
 
-		const effect = pools.effects.get(@intFromEnum(self.current_effect)).?;
+		const effect = pools.get_effect(self.current_effect).?;
 
 		sokol.gfx.applyPipeline(effect.pipeline);
 
-		if (self.current_target_texture) |target_texture| {
-			const texture = pools.textures.get(@intFromEnum(target_texture)).?;
+		const texture = pools.get_texture(self.current_target_texture).?;
 
-			sokol.gfx.applyUniforms(.VS, 0, sokol.gfx.asRange(&lina.orthographic_projection(-1.0, 1.0, .{
-				.left = 0,
-				.top = 0,
-				.right = @floatFromInt(texture.width),
-				.bottom = @floatFromInt(texture.height),
-			})));
-		} else {
-			sokol.gfx.applyUniforms(.VS, 0, sokol.gfx.asRange(&lina.orthographic_projection(-1.0, 1.0, .{
-				.left = 0,
-				.top = 0,
-				.right = @floatFromInt(self.swapchain.width),
-				.bottom = @floatFromInt(self.swapchain.height),
-			})));
+		sokol.gfx.applyUniforms(.VS, 0, sokol.gfx.asRange(&lina.orthographic_projection(-1.0, 1.0, .{
+			.left = 0,
+			.top = 0,
+			.right = @floatFromInt(texture.width),
+			.bottom = @floatFromInt(texture.height),
+		})));
+
+		if (effect.properties.len != 0) {
+			sokol.gfx.applyUniforms(.FS, 0, sokol.gfx.asRange(effect.properties));
 		}
 
-		sokol.gfx.applyUniforms(.FS, 0, sokol.gfx.asRange(effect.properties));
-
 		while (true) {
 			const buffer_index = self.flushed_count / batches_per_buffer;
 			const buffer_offset = self.flushed_count % batches_per_buffer;
@@ -246,7 +243,7 @@ const Frame = struct {
 
 		self.current_effect = command.effect;
 
-		if (pools.effects.get(@intFromEnum(self.current_effect))) |effect| {
+		if (pools.get_effect(self.current_effect)) |effect| {
 			@memcpy(effect.properties, command.properties);
 		}
 	}
@@ -280,17 +277,13 @@ const Frame = struct {
 			pass.action.depth = .{.load_action = .LOAD};
 		}
 
-		if (command.texture) |texture| {
-			pass.attachments = switch (pools.textures.get(@intFromEnum(texture)).?.access) {
-				.static => @panic("Cannot render to static textures"),
-				.render => |render| render.attachments,
-			};
+		pass.attachments = switch (pools.get_texture(self.current_target_texture).?.access) {
+			.static => @panic("Cannot render to static textures"),
+			.empty => @panic("Cannot render to empty textures"),
+			.render => |render| render.attachments,
+		};
 
-			self.current_target_texture = command.texture;
-		} else {
-			pass.swapchain = self.swapchain;
-			self.current_target_texture = null;
-		}
+		self.current_target_texture = command.texture;
 
 		sokol.gfx.beginPass(pass);
 	}
@@ -313,7 +306,7 @@ const Pools = struct {
 
 	const TexturePool = coral.Pool(resources.Texture);
 
-	fn create_effect(self: *Pools, desc: handles.Effect.Desc) !handles.Effect {
+	pub fn create_effect(self: *Pools, desc: handles.Effect.Desc) !handles.Effect {
 		var effect = try resources.Effect.init(desc);
 
 		errdefer effect.deinit();
@@ -321,7 +314,7 @@ const Pools = struct {
 		return @enumFromInt(try self.effects.insert(effect));
 	}
 
-	fn create_texture(self: *Pools, desc: handles.Texture.Desc) !handles.Texture {
+	pub fn create_texture(self: *Pools, desc: handles.Texture.Desc) !handles.Texture {
 		var texture = try resources.Texture.init(desc);
 
 		errdefer texture.deinit();
@@ -329,7 +322,7 @@ const Pools = struct {
 		return @enumFromInt(try self.textures.insert(texture));
 	}
 
-	fn deinit(self: *Pools) void {
+	pub fn deinit(self: *Pools) void {
 		var textures = self.textures.values();
 
 		while (textures.next()) |texture| {
@@ -339,7 +332,7 @@ const Pools = struct {
 		self.textures.deinit();
 	}
 
-	fn destroy_effect(self: *Pools, handle: handles.Effect) bool {
+	pub fn destroy_effect(self: *Pools, handle: handles.Effect) bool {
 		switch (handle) {
 			.default => {},
 
@@ -355,7 +348,7 @@ const Pools = struct {
 		return true;
 	}
 
-	fn destroy_texture(self: *Pools, handle: handles.Texture) bool {
+	pub fn destroy_texture(self: *Pools, handle: handles.Texture) bool {
 		switch (handle) {
 			.default => {},
 
@@ -371,7 +364,15 @@ const Pools = struct {
 		return true;
 	}
 
-	fn init(allocator: std.mem.Allocator) !Pools {
+	pub fn get_effect(self: *Pools, handle: handles.Effect) ?*resources.Effect {
+		return self.effects.get(@intFromEnum(handle));
+	}
+
+	pub fn get_texture(self: *Pools, handle: handles.Texture) ?*resources.Texture {
+		return self.textures.get(@intFromEnum(handle));
+	}
+
+	pub fn init(allocator: std.mem.Allocator) !Pools {
 		var pools = Pools{
 			.effects = EffectPool.init(allocator),
 			.textures = TexturePool.init(allocator),
@@ -381,31 +382,47 @@ const Pools = struct {
 			pools.deinit();
 		}
 
-		_ = try pools.create_effect(.{
-			.fragment_spirv_ops = &spirv.to_ops(@embedFile("./shaders/2d_default.frag.spv")),
-		});
-
-		const default_texture_data = [_]u32{
-			0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF,
-			0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF,
-			0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF,
-			0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF,
-			0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF,
-			0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF,
-			0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF,
-			0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF, 0x800080FF, 0x000000FF,
+		const assert = struct {
+			fn is_handle(expected: anytype, actual: @TypeOf(expected)) void {
+				std.debug.assert(actual == expected);
+			}
 		};
 
-		_ = try pools.create_texture(.{
+		assert.is_handle(handles.Effect.default, try pools.create_effect(.{
+			.fragment_spirv_ops = &spirv.to_ops(@embedFile("./shaders/2d_default.frag.spv")),
+		}));
+
+		assert.is_handle(handles.Texture.default, try pools.create_texture(.{
 			.format = .rgba8,
 
 			.access = .{
 				.static = .{
-					.data = std.mem.asBytes(&default_texture_data),
+					.data = std.mem.asBytes(&[_]u32{
+						0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080,
+						0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000,
+						0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080,
+						0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000,
+						0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080,
+						0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000,
+						0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080,
+						0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000, 0xFF800080, 0xFF000000,
+					}),
+
 					.width = 8,
 				},
 			},
-		});
+		}));
+
+		assert.is_handle(handles.Texture.backbuffer, try pools.create_texture(.{
+			.format = .rgba8,
+
+			.access = .{
+				.render = .{
+					.width = 0,
+					.height = 0,
+				},
+			}
+		}));
 
 		return pools;
 	}
@@ -457,6 +474,8 @@ pub const Work = union (enum) {
 	var pending: coral.asyncio.BlockingQueue(1024, Work) = .{};
 };
 
+var default_sampler: sokol.gfx.Sampler = undefined;
+
 pub fn enqueue_work(work: Work) void {
 	Work.pending.enqueue(work);
 }
@@ -541,6 +560,8 @@ fn run(window: *ext.SDL_Window) !void {
 		.type = .VERTEXBUFFER,
 	});
 
+	default_sampler = sokol.gfx.makeSampler(.{});
+
 	var has_commands_head: ?*Commands = null;
 	var has_commands_tail: ?*Commands = null;
 
@@ -588,6 +609,23 @@ fn run(window: *ext.SDL_Window) !void {
 			},
 
 			.render_frame => |render_frame| {
+				const backbuffer = pools.get_texture(.backbuffer).?;
+
+				if (backbuffer.width != render_frame.width or backbuffer.height != render_frame.height) {
+					backbuffer.deinit();
+
+					backbuffer.* = try resources.Texture.init(.{
+						.format = .rgba8,
+
+						.access = .{
+							.render = .{
+								.width = render_frame.width,
+								.height = render_frame.height,
+							},
+						},
+					});
+				}
+
 				var frame = Frame{
 					.swapchain = .{
 						.width = render_frame.width,
@@ -599,6 +637,51 @@ fn run(window: *ext.SDL_Window) !void {
 					}
 				};
 
+				sokol.gfx.beginPass(pass: {
+					var pass = sokol.gfx.Pass{
+						.action = .{
+							.stencil = .{
+								.load_action = .CLEAR,
+							},
+
+							.depth = .{
+								.load_action = .CLEAR,
+								.clear_value = 0,
+							}
+						},
+					};
+
+					pass.action.colors[0] = .{
+						.load_action = .CLEAR,
+						.clear_value = @bitCast(render_frame.clear_color),
+					};
+
+					pass.attachments = pools.get_texture(.backbuffer).?.access.render.attachments;
+
+					break: pass pass;
+				});
+
+				var has_commands = has_commands_head;
+
+				while (has_commands) |commands| : (has_commands = commands.has_next) {
+					for (commands.submitted_commands()) |command| {
+						try command.process(&pools, &frame);
+					}
+
+					frame.flush(&pools);
+
+					if (frame.current_target_texture != .backbuffer) {
+						frame.set_target(&pools, .{
+							.texture = .backbuffer,
+							.clear_color = null,
+							.clear_depth = null,
+							.clear_stencil = null,
+						});
+					}
+				}
+
+				sokol.gfx.endPass();
+
 				sokol.gfx.beginPass(swapchain_pass: {
 					var pass = sokol.gfx.Pass{
 						.swapchain = frame.swapchain,
@@ -609,29 +692,20 @@ fn run(window: *ext.SDL_Window) !void {
 						},
 					};
 
-					pass.action.colors[0] = .{
-						.clear_value = @bitCast(render_frame.clear_color),
-						.load_action = .CLEAR,
-					};
+					pass.action.colors[0] = .{.load_action = .CLEAR};
 
 					break: swapchain_pass pass;
 				});
 
-				var has_commands = has_commands_head;
+				try frame.draw_texture(&pools, .{
+					.texture = .backbuffer,
 
-				while (has_commands) |commands| : (has_commands = commands.has_next) {
-					for (commands.submitted_commands()) |command| {
-						try command.process(&pools, &frame);
-					}
-
-					if (frame.current_target_texture != .default) {
-						frame.set_target(&pools, .{
-							.clear_color = null,
-							.clear_depth = null,
-							.clear_stencil = null,
-						});
-					}
-				}
+					.transform = .{
+						.origin = .{@as(f32, @floatFromInt(render_frame.width)) / 2, @as(f32, @floatFromInt(render_frame.height)) / 2},
+						.xbasis = .{@floatFromInt(render_frame.width), 0},
+						.ybasis = .{0, @floatFromInt(render_frame.height)},
+					},
+				});
 
 				frame.flush(&pools);
 				sokol.gfx.endPass();

src/ona/gfx/resources.zig

@@ -123,11 +123,11 @@ pub const Effect = struct {
 						.float2 => .FLOAT2,
 						.float3 => .FLOAT3,
 						.float4 => .FLOAT4,
-						.int => .INT,
-						.int2 => .INT2,
-						.int3 => .INT3,
-						.int4 => .INT4,
-						.mat4 => .MAT4,
+						.integer => .INT,
+						.integer2 => .INT2,
+						.integer3 => .INT3,
+						.integer4 => .INT4,
+						.matrix4 => .MAT4,
 					},
 
 					.name = uniform.name,
@@ -244,19 +244,18 @@ pub const Texture = struct {
 	access: Access,
 
 	pub const Access = union (enum) {
+		empty,
 		render: RenderAccess,
 		static: StaticAccess,
 	};
 
 	pub const RenderAccess = struct {
-		sampler: sokol.gfx.Sampler,
 		color_image: sokol.gfx.Image,
 		depth_image: sokol.gfx.Image,
 		attachments: sokol.gfx.Attachments,
 	};
 
 	pub const StaticAccess = struct {
-		sampler: sokol.gfx.Sampler,
 		image: sokol.gfx.Image,
 	};
 
@@ -265,14 +264,14 @@ pub const Texture = struct {
 			.render => |render| {
 				sokol.gfx.destroyImage(render.color_image);
 				sokol.gfx.destroyImage(render.depth_image);
-				sokol.gfx.destroySampler(render.sampler);
 				sokol.gfx.destroyAttachments(render.attachments);
 			},
 
 			.static => |static| {
 				sokol.gfx.destroyImage(static.image);
-				sokol.gfx.destroySampler(static.sampler);
 			},
+
+			.empty => {},
 		}
 
 		self.* = undefined;
@@ -286,6 +285,14 @@ pub const Texture = struct {
 
 		switch (desc.access) {
 			.render => |render| {
+				if (render.width == 0 or render.height == 0) {
+					return .{
+						.width = render.width,
+						.height = render.height,
+						.access = .empty,
+					};
+				}
+
 				const color_image = sokol.gfx.makeImage(.{
 					.pixel_format = pixel_format,
 					.width = render.width,
@@ -314,8 +321,6 @@ pub const Texture = struct {
 					break: attachments_desc attachments_desc;
 				});
 
-				const sampler = sokol.gfx.makeSampler(.{});
-
 				return .{
 					.width = render.width,
 					.height = render.height,
@@ -323,11 +328,10 @@ pub const Texture = struct {
 					.access = .{
 						.render = .{
 							.attachments = attachments,
-							.sampler = sampler,
 							.color_image = color_image,
 							.depth_image = depth_image,
 						},
-					}
+					},
 				};
 			},
 
@@ -336,6 +340,14 @@ pub const Texture = struct {
 					return error.OutOfMemory;
 				};
 
+				if (static.width == 0 or height == 0) {
+					return .{
+						.width = static.width,
+						.height = height,
+						.access = .empty,
+					};
+				}
+
 				const image = sokol.gfx.makeImage(image_desc: {
 					var image_desc = sokol.gfx.ImageDesc{
 						.height = height,
@@ -348,10 +360,7 @@ pub const Texture = struct {
 					break: image_desc image_desc;
 				});
 
-				const sampler = sokol.gfx.makeSampler(.{});
-
 				errdefer {
-					sokol.gfx.destroySampler(sampler);
 					sokol.gfx.destroyImage(image);
 				}
 
@@ -362,7 +371,6 @@ pub const Texture = struct {
 					.access = .{
 						.static = .{
 							.image = image,
-							.sampler = sampler,
 						},
 					},
 				};

src/ona/gfx/shaders/2d_default.vert

@@ -21,8 +21,9 @@ void main() {
 	const vec2 world_position = instance_origin + mesh_xy.x * instance_xbasis + mesh_xy.y * instance_ybasis;
 	const vec2 projected_position = (projection_matrix * vec4(world_position, 0, 1)).xy;
 	const vec2 rect_size = instance_rect.zw - instance_rect.xy;
+	const vec4 screen_position = vec4(projected_position, instance_depth, 1.0);
 
-	gl_Position = vec4(projected_position, instance_depth, 1.0);
+	gl_Position = screen_position;
 	color = instance_tint;
 	uv = instance_rect.xy + (mesh_uv * rect_size);
 }

src/ona/gfx/spirv.zig

@@ -67,11 +67,11 @@ pub const Stage = struct {
 			float2,
 			float3,
 			float4,
-			int,
-			int2,
-			int3,
-			int4,
-			mat4,
+			integer,
+			integer2,
+			integer3,
+			integer4,
+			matrix4,
 		};
 	};
 
@@ -82,29 +82,27 @@ pub const Stage = struct {
 		pub const max_uniforms = 16;
 
 		pub fn size(self: UniformBlock) usize {
-			const alignment: usize = switch (self.layout) {
-				.std140 => 16,
-			};
-
 			var accumulated_size: usize = 0;
 
 			for (self.uniforms) |uniform| {
-				const type_size = @max(1, uniform.len) * @as(usize, switch (uniform.type) {
+				accumulated_size += @max(1, uniform.len) * @as(usize, switch (uniform.type) {
 					.float => 4,
 					.float2 => 8,
 					.float3 => 12,
 					.float4 => 16,
-					.int => 4,
-					.int2 => 8,
-					.int3 => 12,
-					.int4 => 16,
-					.mat4 => 64,
+					.integer => 4,
+					.integer2 => 8,
+					.integer3 => 12,
+					.integer4 => 16,
+					.matrix4 => 64,
 				});
-
-				accumulated_size += (type_size + (alignment - 1)) & ~(alignment - 1);
 			}
 
-			return accumulated_size;
+			const alignment: usize = switch (self.layout) {
+				.std140 => 16,
+			};
+
+			return (accumulated_size + (alignment - 1)) & ~(alignment - 1);
 		}
 	};
 
@@ -212,7 +210,7 @@ pub const Stage = struct {
 					.type = try switch (ext.spvc_type_get_basetype(member_type_handle)) {
 						ext.SPVC_BASETYPE_FP32 => switch (ext.spvc_type_get_vector_size(member_type_handle)) {
 							4 => switch (ext.spvc_type_get_columns(member_type_handle)) {
-								4 => Uniform.Type.mat4,
+								4 => Uniform.Type.matrix4,
 								1 => Uniform.Type.float4,
 								else => error.UnsupportedSPIRV,
 							},
@@ -224,10 +222,10 @@ pub const Stage = struct {
 						},
 
 						ext.SPVC_BASETYPE_INT32 => try switch (ext.spvc_type_get_vector_size(member_type_handle)) {
-							1 => Uniform.Type.int,
-							2 => Uniform.Type.int2,
-							3 => Uniform.Type.int3,
-							4 => Uniform.Type.int4,
+							1 => Uniform.Type.integer,
+							2 => Uniform.Type.integer2,
+							3 => Uniform.Type.integer3,
+							4 => Uniform.Type.integer4,
 							else => error.UnsupportedSPIRV,
 						},
 

src/ona/ona.zig

@@ -75,6 +75,7 @@ pub fn start_app(setup: Setup, options: Options) anyerror!void {
 	const app = try world.set_get_resource(App{
 		.events = &events,
 		.target_frame_time = 1.0 / @as(f64, @floatFromInt(options.tick_rate)),
+		.elapsed_time = 0,
 		.is_running = true,
 	});
 
@@ -85,7 +86,8 @@ pub fn start_app(setup: Setup, options: Options) anyerror!void {
 	try setup(&world, events);
 	try world.run_event(events.load);
 
-	var ticks_previous = std.time.milliTimestamp();
+	const ticks_initial = std.time.milliTimestamp();
+	var ticks_previous = ticks_initial;
 	var accumulated_time = @as(f64, 0);
 
 	while (app.is_running) {
@@ -93,6 +95,7 @@ pub fn start_app(setup: Setup, options: Options) anyerror!void {
 		const milliseconds_per_second = 1000.0;
 		const delta_time = @as(f64, @floatFromInt(ticks_current - ticks_previous)) / milliseconds_per_second;
 
+		app.elapsed_time = @as(f64, @floatFromInt(ticks_current - ticks_initial)) / milliseconds_per_second;
 		ticks_previous = ticks_current;
 		accumulated_time += delta_time;