render text

1 files changed, 88 insertions, 5 deletions

diff --git a/src/graphics.rs b/src/graphics.rs
index 2b96a7a..bab9f05 100644
--- a/src/graphics.rs
+++ b/src/graphics.rs
@@ -1,12 +1,27 @@
-use std::{borrow::Cow, sync::Arc};
+use glam::{Vec2, Vec4};
+use std::{borrow::Cow, mem, slice, sync::Arc};
 use wgpu::*;
 use winit::{dpi::PhysicalSize, event_loop::OwnedDisplayHandle, window::Window};
 
+pub mod command;
 mod font;
 mod texture;
 
+use command::RenderCommand;
 use font::CharAtlas;
 
+pub const INSTANCE_MAX_COUNT: u64 = 128;
+
+#[repr(C)]
+struct InstanceData {
+    // 中央原点 左→右[-1, 1] 下→上[-1, 1]
+    position: Vec2,
+    // 拡大率 (width, height): [0, 1]^2
+    scale: Vec2,
+    // (u, v, width, height): [0, 1]^4
+    uv: Vec4,
+}
+
 pub enum AcquireSurfaceTextureResult {
     Ok(SurfaceTexture),
     ShouldSkip,
@@ -22,6 +37,8 @@ pub struct Renderer {
     present_mode: PresentMode,
     pipeline: RenderPipeline,
 
+    instances: Buffer,
+    trans_bind_group: BindGroup,
     char_atlas: CharAtlas,
     fixed_bind_group: BindGroup,
 }
@@ -61,6 +78,19 @@ impl Renderer {
             source: ShaderSource::Wgsl(Cow::Borrowed(include_str!("shader.wgsl"))),
         });
 
+        let trans_bind_group_layout = device.create_bind_group_layout(&BindGroupLayoutDescriptor {
+            label: None,
+            entries: &[BindGroupLayoutEntry {
+                binding: 0,
+                visibility: ShaderStages::VERTEX,
+                ty: BindingType::Buffer {
+                    ty: BufferBindingType::Storage { read_only: true },
+                    has_dynamic_offset: false,
+                    min_binding_size: None,
+                },
+                count: None,
+            }],
+        });
         let fixed_bind_group_layout = device.create_bind_group_layout(&BindGroupLayoutDescriptor {
             label: None,
             entries: &[
@@ -84,7 +114,10 @@ impl Renderer {
         });
         let pipeline_layout = device.create_pipeline_layout(&PipelineLayoutDescriptor {
             label: None,
-            bind_group_layouts: &[Some(&fixed_bind_group_layout)],
+            bind_group_layouts: &[
+                Some(&trans_bind_group_layout),
+                Some(&fixed_bind_group_layout),
+            ],
             immediate_size: 0,
         });
         let pipeline = device.create_render_pipeline(&RenderPipelineDescriptor {
@@ -117,6 +150,26 @@ impl Renderer {
             cache: None,
         });
 
+        // NOTE: インスタンスバッファは固定長で使いまわすので、ここで1個だけ作成すれば良い。
+        let instances = device.create_buffer(&BufferDescriptor {
+            label: None,
+            size: mem::size_of::<InstanceData>() as u64 * INSTANCE_MAX_COUNT,
+            usage: BufferUsages::STORAGE | BufferUsages::COPY_DST,
+            mapped_at_creation: false,
+        });
+        let trans_bind_group = device.create_bind_group(&BindGroupDescriptor {
+            label: None,
+            layout: &trans_bind_group_layout,
+            entries: &[BindGroupEntry {
+                binding: 0,
+                resource: BindingResource::Buffer(BufferBinding {
+                    buffer: &instances,
+                    offset: 0,
+                    size: None,
+                }),
+            }],
+        });
+
         // NOTE: 本ゲームではlinearなサンプラしか用意しないので、ここで1個だけ作成すれば良い。
         let sampler = device.create_sampler(&SamplerDescriptor {
             label: None,
@@ -153,6 +206,8 @@ impl Renderer {
             view_format,
             present_mode,
             pipeline,
+            instances,
+            trans_bind_group,
             char_atlas,
             fixed_bind_group,
         };
@@ -185,7 +240,12 @@ impl Renderer {
         }
     }
 
-    pub fn render(&mut self, window: &Window, current_texture: SurfaceTexture) {
+    pub fn render(
+        &mut self,
+        window: &Window,
+        current_texture: SurfaceTexture,
+        commands: &[RenderCommand],
+    ) {
         let surface_texture_view = current_texture.texture.create_view(&TextureViewDescriptor {
             format: Some(self.view_format),
             ..Default::default()
@@ -210,9 +270,32 @@ impl Renderer {
         });
 
         render_pass.set_pipeline(&self.pipeline);
-        render_pass.set_bind_group(0, &self.fixed_bind_group, &[]);
+        render_pass.set_bind_group(0, &self.trans_bind_group, &[]);
+        render_pass.set_bind_group(1, &self.fixed_bind_group, &[]);
 
-        // TODO: 描画
+        let size = window.inner_size().to_logical::<f32>(window.scale_factor());
+        let mut instances = Vec::new();
+        for command in commands {
+            command.build(
+                size.width,
+                size.height,
+                window.scale_factor() as f32,
+                &self.queue,
+                &mut self.char_atlas,
+                &mut instances,
+            );
+            // TODO: 今はfont_texしか使わないので1ドローコールで済むが、
+            //       bind groupを変える必要があればドローコールを切る。
+        }
+        instances.truncate(INSTANCE_MAX_COUNT as usize);
+        let bytes = unsafe {
+            slice::from_raw_parts(
+                instances.as_ptr() as *const u8,
+                mem::size_of_val(instances.as_slice()),
+            )
+        };
+        self.queue.write_buffer(&self.instances, 0, bytes);
+        render_pass.draw(0..4, 0..instances.len() as u32);
 
         drop(render_pass);