Implemented hidden texture in render code

crates/render/shaders/object.wgsl

@@ -103,7 +103,7 @@ fn transform_vertex(obj: ObjectData, vertex_position: vec2<f32>, texture_index:
 		);
 	}
 
-	return vec4<f32>(pos, 0.0, 1.0);;
+	return vec4<f32>(pos, 0.0, 1.0);
 }
 
 @vertex
@@ -113,19 +113,41 @@ fn vertex_main(
 ) -> VertexOutput {
 	var out: VertexOutput;
 
+	// Pick texture size by the size of the visible texture
+	// (texture index 0 is special, it's the "hidden" texture)
+	if instance.texture_index.x == 0u && instance.texture_index.y == 0u {
+		out.position = vec4<f32>(0.0, 0.0, 0.0, 1.0);
+	} else if instance.texture_index.x == 0u {
+		out.position = transform_vertex(
+			objects[instance.object_index],
+			vertex.position.xy,
+			instance.texture_index.y
+		);
+	} else if instance.texture_index.y == 0u {
 		out.position = transform_vertex(
 			objects[instance.object_index],
 			vertex.position.xy,
 			instance.texture_index.x
 		);
+	} else {
+		out.position = transform_vertex(
+			objects[instance.object_index],
+			vertex.position.xy,
+			instance.texture_index.x
+		);
+	}
+
 
 
-	// Compute texture coordinates
-	let age = global_data.current_time.x;
 	out.tween = instance.texture_fade;
 
+	// Texture 0 is special, it's the empty texture
+	if instance.texture_index.x == 0u {
+		out.texture_index_a = 0u;
+		out.texture_coords_a = vec2(0.0, 0.0);
+	} else {
 		let t = global_atlas[instance.texture_index.x];
-	out.texture_index_a = u32(t.atlas_texture);
+		out.texture_index_a = t.atlas_texture;
 		out.texture_coords_a = vec2(t.xpos, t.ypos);
 		if vertex.texture_coords.x == 1.0 {
 			out.texture_coords_a = out.texture_coords_a + vec2(t.width, 0.0);
@@ -133,7 +155,12 @@ fn vertex_main(
 		if vertex.texture_coords.y == 1.0 {
 			out.texture_coords_a = out.texture_coords_a + vec2(0.0, t.height);
 		}
+	}
 
+	if instance.texture_index.y == 0u {
+		out.texture_index_b = u32(0u);
+		out.texture_coords_b = vec2(0.0, 0.0);
+	} else {
 		let b = global_atlas[instance.texture_index.y];
 		out.texture_index_b = u32(b.atlas_texture);
 		out.texture_coords_b = vec2(b.xpos, b.ypos);
@@ -143,6 +170,7 @@ fn vertex_main(
 		if vertex.texture_coords.y == 1.0 {
 			out.texture_coords_b = out.texture_coords_b + vec2(0.0, b.height);
 		}
+	}
 
 	return out;
 }
@@ -150,19 +178,42 @@ fn vertex_main(
 
 @fragment
 fn fragment_main(in: VertexOutput) -> @location(0) vec4<f32> {
-	return mix(
-		textureSampleLevel(
+
+	var texture_a: vec4<f32> = vec4(0.0, 0.0, 0.0, 0.0);
+	if !(
+		(in.texture_index_a == 0u) &&
+		(in.texture_coords_a.x == 0.0) &&
+		(in.texture_coords_a.y == 0.0)
+	) {
+		texture_a = textureSampleLevel(
 			texture_array[in.texture_index_a],
 			sampler_array[0],
 			in.texture_coords_a,
 			0.0
-		).rgba,
-		textureSampleLevel(
+		).rgba;
+	}
+
+
+	var texture_b: vec4<f32> = vec4(0.0, 0.0, 0.0, 0.0);
+	if !(
+		(in.texture_index_b == 0u) &&
+		(in.texture_coords_b.x == 0.0) &&
+		(in.texture_coords_b.y == 0.0)
+	) {
+		texture_b = textureSampleLevel(
 			texture_array[in.texture_index_b],
 			sampler_array[0],
 			in.texture_coords_b,
 			0.0
-		).rgba,
+		).rgba;
+	}
+
+	let color = mix(
+		texture_a,
+		texture_b,
 		in.tween
 	);
+
+
+	return color;
 }

crates/render/src/gpustate/render.rs

@@ -306,7 +306,7 @@ impl<'a> super::GPUState {
 				],
 				window_scale: [self.state.window.scale_factor() as f32, 0.0],
 				window_aspect: [self.state.window_aspect, 0.0],
-				starfield_sprite: [input.ct.get_config().starfield_texture, 0],
+				starfield_sprite: [input.ct.get_config().starfield_texture.into(), 0],
 				starfield_tile_size: [input.ct.get_config().starfield_size, 0.0],
 				starfield_size_limits: [
 					input.ct.get_config().starfield_min_size,

crates/render/src/texturearray.rs

@@ -112,8 +112,15 @@ impl TextureArray {
 		for sprite in &ct.sprites {
 			for section in sprite.iter_sections() {
 				for idx in &section.frames {
-					let image = ct.get_image(*idx);
-					image_locations.data[*idx as usize] = AtlasImageLocation {
+					// Some atlas entries may be written twice here,
+					// but that's not really a problem. They're all the same!
+					//
+					// This happens rarely---only when two different sections
+					// use the same frame.
+					let idx = NonZeroU32::new(*idx);
+					if idx.is_some() {
+						let image = ct.get_image(idx.unwrap());
+						image_locations.data[idx.unwrap().get() as usize] = AtlasImageLocation {
 							xpos: image.x,
 							ypos: image.y,
 							width: image.w,
@@ -124,6 +131,7 @@ impl TextureArray {
 					}
 				}
 			}
+		}
 
 		let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
 			address_mode_u: wgpu::AddressMode::ClampToEdge,