Use GPU picking for line(like) primitives, fix interactive flags

crates/re_renderer/examples/2d.rs

@@ -67,7 +67,7 @@ impl framework::Example for Render2D {
             splits[0].resolution_in_pixel[1] as f32,
         );
 
-        let mut line_strip_builder = LineStripSeriesBuilder::<()>::new(re_ctx);
+        let mut line_strip_builder = LineStripSeriesBuilder::new(re_ctx);
 
         // Blue rect outline around the bottom right quarter.
         {
@@ -182,7 +182,7 @@ impl framework::Example for Render2D {
             }
         }
 
-        let line_strip_draw_data = line_strip_builder.to_draw_data(re_ctx);
+        let line_strip_draw_data = line_strip_builder.to_draw_data(re_ctx).unwrap();
         let point_draw_data = point_cloud_builder.to_draw_data(re_ctx).unwrap();
 
         let image_scale = 4.0;

crates/re_renderer/examples/depth_cloud.rs

@@ -312,7 +312,7 @@ impl framework::Example for RenderDepthClouds {
         let world_from_model = rotation * translation_center * scale;
 
         let frame_draw_data = {
-            let mut builder = LineStripSeriesBuilder::<()>::new(re_ctx);
+            let mut builder = LineStripSeriesBuilder::new(re_ctx);
             {
                 let mut line_batch = builder.batch("frame").world_from_obj(world_from_model);
                 line_batch.add_box_outline(glam::Affine3A::from_scale_rotation_translation(
@@ -321,7 +321,7 @@ impl framework::Example for RenderDepthClouds {
                     glam::Vec3::ONE * 0.5,
                 ));
             }
-            builder.to_draw_data(re_ctx)
+            builder.to_draw_data(re_ctx).unwrap()
         };
 
         let image_draw_data = RectangleDrawData::new(

crates/re_renderer/examples/multiview.rs

@@ -84,7 +84,7 @@ fn build_lines(re_ctx: &mut RenderContext, seconds_since_startup: f32) -> LineDr
     // Calculate some points that look nice for an animated line.
     let lorenz_points = lorenz_points(seconds_since_startup);
 
-    let mut builder = LineStripSeriesBuilder::<()>::new(re_ctx);
+    let mut builder = LineStripSeriesBuilder::new(re_ctx);
     {
         let mut batch = builder.batch("lines without transform");
 
@@ -125,7 +125,7 @@ fn build_lines(re_ctx: &mut RenderContext, seconds_since_startup: f32) -> LineDr
         .radius(Size::new_scene(0.1))
         .flags(LineStripFlags::CAP_END_TRIANGLE);
 
-    builder.to_draw_data(re_ctx)
+    builder.to_draw_data(re_ctx).unwrap()
 }
 
 enum CameraControl {

crates/re_renderer/shader/lines.wgsl

@@ -10,6 +10,8 @@
 var line_strip_texture: texture_2d<f32>;
 @group(1) @binding(1)
 var position_data_texture: texture_2d<u32>;
+@group(1) @binding(2)
+var picking_instance_id_texture: texture_2d<u32>;
 
 struct DrawDataUniformBuffer {
     radius_boost_in_ui_points: f32,
@@ -19,21 +21,22 @@ struct DrawDataUniformBuffer {
     // if we wouldn't add padding here, which isn't available on WebGL.
     _padding: Vec4,
 };
-@group(1) @binding(2)
+@group(1) @binding(3)
 var<uniform> draw_data: DrawDataUniformBuffer;
 
 struct BatchUniformBuffer {
     world_from_obj: Mat4,
     outline_mask_ids: UVec2,
+    picking_layer_object_id: UVec2,
 };
 @group(2) @binding(0)
 var<uniform> batch: BatchUniformBuffer;
 
 
 // textureLoad needs i32 right now, so we use that with all sizes & indices to avoid casts
 // https://github.com/gfx-rs/naga/issues/1997
-const LINESTRIP_TEXTURE_SIZE: i32 = 512;
-const POSITION_DATA_TEXTURE_SIZE: i32 = 256;
+const POSITION_TEXTURE_SIZE: i32 = 512;
+const LINE_STRIP_TEXTURE_SIZE: i32 = 256;
 
 // Flags
 // See lines.rs#LineStripFlags
@@ -69,20 +72,25 @@ struct VertexOut {
 
     @location(5) @interpolate(flat)
     fragment_flags: u32,
+
+    @location(6) @interpolate(flat)
+    picking_instance_id: UVec2,
 };
 
 struct LineStripData {
     color: Vec4,
     unresolved_radius: f32,
     stippling: f32,
     flags: u32,
+    picking_instance_id: UVec2,
 }
 
 // Read and unpack line strip data at a given location
 fn read_strip_data(idx: u32) -> LineStripData {
     // can be u32 once https://github.com/gfx-rs/naga/issues/1997 is solved
     let idx = i32(idx);
-    var raw_data = textureLoad(position_data_texture, IVec2(idx % POSITION_DATA_TEXTURE_SIZE, idx / POSITION_DATA_TEXTURE_SIZE), 0).xy;
+    let coord = IVec2(idx % LINE_STRIP_TEXTURE_SIZE, idx / LINE_STRIP_TEXTURE_SIZE);
+    var raw_data = textureLoad(position_data_texture, coord, 0).xy;
 
     var data: LineStripData;
     data.color = linear_from_srgba(unpack4x8unorm_workaround(raw_data.x));
@@ -91,6 +99,7 @@ fn read_strip_data(idx: u32) -> LineStripData {
     data.unresolved_radius = unpack2x16float(raw_data.y).y;
     data.flags = ((raw_data.y >> 8u) & 0xFFu);
     data.stippling = f32((raw_data.y >> 16u) & 0xFFu) * (1.0 / 255.0);
+    data.picking_instance_id = textureLoad(picking_instance_id_texture, coord, 0).rg;
     return data;
 }
 
@@ -103,7 +112,7 @@ struct PositionData {
 fn read_position_data(idx: u32) -> PositionData {
     // can be u32 once https://github.com/gfx-rs/naga/issues/1997 is solved
     let idx = i32(idx);
-    var raw_data = textureLoad(line_strip_texture, IVec2(idx % LINESTRIP_TEXTURE_SIZE, idx / LINESTRIP_TEXTURE_SIZE), 0);
+    var raw_data = textureLoad(line_strip_texture, IVec2(idx % POSITION_TEXTURE_SIZE, idx / POSITION_TEXTURE_SIZE), 0);
 
     var data: PositionData;
     let pos_4d = batch.world_from_obj * Vec4(raw_data.xyz, 1.0);
@@ -262,6 +271,7 @@ fn vs_main(@builtin(vertex_index) vertex_idx: u32) -> VertexOut {
     out.active_radius = active_radius;
     out.fragment_flags = strip_data.flags &
                     (NO_COLOR_GRADIENT | (u32(is_cap_triangle) * select(CAP_START_ROUND, CAP_END_ROUND, is_right_triangle)));
+    out.picking_instance_id = strip_data.picking_instance_id;
 
     return out;
 }
@@ -305,7 +315,7 @@ fn fs_main_picking_layer(in: VertexOut) -> @location(0) UVec4 {
     if coverage < 0.5 {
         discard;
     }
-    return UVec4(0u, 0u, 0u, 0u); // TODO(andreas): Implement picking layer id pass-through.
+    return UVec4(batch.picking_layer_object_id, in.picking_instance_id);
 }
 
 @fragment