1 files changed, 177 insertions, 0 deletions
diff --git a/src/tacmap/fleet_render.rs b/src/tacmap/fleet_render.rs
new file mode 100644
index 0000000..ba21318
--- /dev/null
+++ b/src/tacmap/fleet_render.rs
@@ -0,0 +1,177 @@
+use std::error::Error;
+
+use crate::fleet::FleetsManager;
+use crate::solar_system::orbit::StaticOrbiter;
+use crate::solar_system::{Kilometers};
+use crate::timeman::{Second};
+use crate::wgpuctx::{WgpuCtx, pipeline::RenderPipelineBuilder};
+
+use super::*;
+
+pub struct FleetRenderer
+{
+    last_time: Option<Second>,
+
+    pipeline: wgpu::RenderPipeline,
+
+    fleet_instance_buffer: Option<(usize, wgpu::Buffer)>
+}
+
+struct FleetInstance
+{
+    offset: cgmath::Vector3<Kilometers>,
+    origin: cgmath::Vector3<Kilometers>,
+    heading: cgmath::Vector2<cgmath::Rad<f32>>
+}
+
+#[repr(C)]
+#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
+struct FleetInstanceRaw
+{
+    rotmat: [[f32;3];3],
+    origin: [f32;3],
+    offset: [f32;3],
+}
+
+impl FleetRenderer
+{
+    pub fn new(
+        wgpuctx: &WgpuCtx)
+    -> Self {
+        let shader = wgpuctx.create_shader(
+            wgpu::include_wgsl!(concat!(
+                    env!("CARGO_MANIFEST_DIR"),
+                    "/assets/shaders/tacmap/fleet.wgsl")
+        ));
+
+        let render_pipeline = RenderPipelineBuilder::new(&shader)
+            .add_bindgroup(&Camera::bindgroup_layout(wgpuctx))
+            .add_vertex_layout(FleetInstanceRaw::descr())
+            .cull_mode(None)
+            .build(Some("Tactical map fleet render pipeline"), wgpuctx);
+
+        Self {
+            last_time: None,
+            pipeline: render_pipeline,
+            fleet_instance_buffer: None
+        }
+    }
+
+    pub fn update(
+        &mut self,
+        wgpuctx: &WgpuCtx,
+        fleets_manager: &FleetsManager,
+        solar_system: &SolarSystem,
+        time: Second)
+    -> Result<(), Box<dyn Error>>
+    {
+        //If the last updated time is the same, we don't need to update
+        //the positions of all the bodies.
+        if self.last_time.is_some_and(|last_time| { last_time == time }) {
+            return Ok(());
+        }
+
+        self.last_time = Some(time);
+
+        if let Some((_, buffer)) = &self.fleet_instance_buffer {
+            buffer.destroy();
+            self.fleet_instance_buffer = None;
+        }
+
+        let fleets = solar_system.fleets(fleets_manager);
+        let fleets_instances = fleets.iter().filter_map(|id| {
+            let fleet = match fleets_manager.entry(*id) {
+                Some(fleet) => fleet,
+                None => { return None; }
+            };
+            let heading = fleet.heading();
+            let offset = fleet.offset_position();
+            let origin = match fleet.orbit() {
+                Some(orbit) => {
+                    let origin_body = solar_system.body(orbit.parent());
+                    origin_body.absolute_position(solar_system, time)
+                },
+                None => cgmath::vec3(0.0, 0.0, 0.0)
+            };
+            Some(
+                FleetInstance {
+                    heading: *heading,
+                    offset: *offset,
+                    origin: origin
+                }.raw()
+            )
+        }).collect::<Vec<_>>();
+        let fleets_buffer = wgpuctx.create_buffer_init(
+            &wgpu::util::BufferInitDescriptor {
+                label: None,
+                contents: bytemuck::cast_slice(fleets_instances.as_slice()),
+                usage: wgpu::BufferUsages::VERTEX
+        });
+
+        self.fleet_instance_buffer = Some((fleets.len(), fleets_buffer));
+
+        Ok(())
+    }
+
+    pub fn render(
+        &self,
+        pass: &mut wgpu::RenderPass,
+        camera: &Camera)
+    {
+        let (num_fleets, fleets_buffer) = match &self.fleet_instance_buffer {
+            Some(tuple) => tuple,
+            None => return
+        };
+        if *num_fleets == 0 { return; }
+
+        pass.set_pipeline(&self.pipeline);
+        pass.set_bind_group(0, camera.bindgroup(), &[]);
+
+        pass.set_vertex_buffer(0, fleets_buffer.slice(..));
+
+        pass.draw(0..6, 0..*num_fleets as _);
+    }
+} // impl RenderState
+
+impl FleetInstance 
+{
+    fn raw(&self) -> FleetInstanceRaw
+    {
+        FleetInstanceRaw {
+            rotmat: (cgmath::Matrix3::from_angle_x(self.heading.x) *
+                     cgmath::Matrix3::from_angle_y(self.heading.y))
+                    .into(),
+            origin: [
+                self.origin.x as f32,
+                self.origin.y as f32,
+                self.origin.z as f32
+            ],
+            offset: [
+                self.offset.x as f32,
+                self.offset.y as f32,
+                self.offset.z as f32
+            ]
+        }
+    }
+} // impl BodyInstance
+
+impl FleetInstanceRaw 
+{
+    const ATTRIBS: [wgpu::VertexAttribute;5] =
+        wgpu::vertex_attr_array![
+        0 => Float32x3, 1 => Float32x3, 2 => Float32x3,
+        3 => Float32x3,
+        4 => Float32x3
+        ];
+
+    pub fn descr()
+    -> wgpu::VertexBufferLayout<'static> {
+        use std::mem;
+
+        wgpu::VertexBufferLayout {
+            array_stride: mem::size_of::<Self>() as wgpu::BufferAddress,
+            step_mode: wgpu::VertexStepMode::Instance,
+            attributes: &Self::ATTRIBS
+        }
+    }
+}