From a6d66152314caa769c5e5010b7276a7b96b209db Mon Sep 17 00:00:00 2001
From: Dennis Ranke <dennis.ranke@gmail.com>
Date: Sun, 10 Jul 2022 12:18:53 +0200
Subject: [PATCH] only draw area covered by framebuffer

---
 uw8-window/src/crt.wgsl | 13 +++++--------
 uw8-window/src/gpu.rs   |  9 +++++++--
 uw8-window/src/main.rs  | 21 +++++++++++++++------
 3 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/uw8-window/src/crt.wgsl b/uw8-window/src/crt.wgsl
index 569568b..22400a0 100644
--- a/uw8-window/src/crt.wgsl
+++ b/uw8-window/src/crt.wgsl
@@ -14,10 +14,11 @@ fn vs_main(
     @builtin(vertex_index) in_vertex_index: u32,
 ) -> VertexOutput {
     var out: VertexOutput;
-    let x = (1.0 - f32(in_vertex_index)) * 3.0;
-    let y = f32(in_vertex_index & 1u) * 3.0 - 1.0;
-    out.clip_position = vec4<f32>(x, y, 0.0, 1.0);
-    out.tex_coords = vec2<f32>(x, y) * uniforms.texture_scale.xy + vec2<f32>(160.0, 120.0);
+    let i = in_vertex_index / 3u + in_vertex_index % 3u;
+    let x = -1.0 + f32(i % 2u) * 322.0;
+    let y = -1.0 + f32(i / 2u) * 242.0;
+    out.clip_position = vec4<f32>((vec2<f32>(x, y) - vec2<f32>(160.0, 120.0)) / uniforms.texture_scale.xy, 0.0, 1.0);
+    out.tex_coords = vec2<f32>(x, y);
     return out;
 }
 
@@ -39,10 +40,6 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
     let o = vec2<f32>(0.5) - (in.tex_coords - pixel);
     let pixel = vec2<i32>(pixel);
     
-    if(pixel.x < -1 || pixel.y < -1 || pixel.x > 320 || pixel.y > 240) {
-        return vec4<f32>(0.0, 0.0, 0.0, 1.0);
-    }
-    
     let offset_x = o.xxxx + vec4<f32>(-0.125, 0.375, 0.125, -0.375) * uniforms.texture_scale.z;
     let offset_y = o.yyyy + vec4<f32>(-0.375, -0.125, 0.375, 0.125) * uniforms.texture_scale.z;
     
diff --git a/uw8-window/src/gpu.rs b/uw8-window/src/gpu.rs
index 718a217..986b371 100644
--- a/uw8-window/src/gpu.rs
+++ b/uw8-window/src/gpu.rs
@@ -404,7 +404,12 @@ impl Window {
                                     view: &view,
                                     resolve_target: None,
                                     ops: wgpu::Operations {
-                                        load: wgpu::LoadOp::Load,
+                                        load: wgpu::LoadOp::Clear(wgpu::Color {
+                                            r: 0.0,
+                                            g: 0.0,
+                                            b: 0.0,
+                                            a: 1.0,
+                                        }),
                                         store: true,
                                     },
                                 })],
@@ -413,7 +418,7 @@ impl Window {
 
                         render_pass.set_pipeline(&render_pipeline);
                         render_pass.set_bind_group(0, &crt_bind_group, &[]);
-                        render_pass.draw(0..3, 0..1);
+                        render_pass.draw(0..6, 0..1);
                     }
 
                     queue.submit(std::iter::once(encoder.finish()));
diff --git a/uw8-window/src/main.rs b/uw8-window/src/main.rs
index b58f4f1..1bcf986 100644
--- a/uw8-window/src/main.rs
+++ b/uw8-window/src/main.rs
@@ -1,4 +1,4 @@
-use std::time::{Duration, Instant};
+use std::time::Instant;
 
 fn main() {
     env_logger::Builder::from_env(env_logger::Env::default().default_filter_or("info")).init();
@@ -15,13 +15,22 @@ fn main() {
         palette[i as usize] = r + (g << 8) + (b << 16);
     }
 
-    let mut prev_frame = Instant::now();
+    let mut fps_start = Instant::now();
+    let mut fps_counter = 0;
 
-    uw8_window::run(move |gpu_framebuffer, _gamepads, _reset| {
-        draw_frame(&mut framebuffer, start_time.elapsed().as_secs_f32());
+    uw8_window::run(true, move |gpu_framebuffer, _gamepads, _reset| {
+        for _ in 0..1 {
+            draw_frame(&mut framebuffer, start_time.elapsed().as_secs_f32());
+        }
         gpu_framebuffer.update(&framebuffer, bytemuck::cast_slice(&palette));
-        prev_frame += Duration::from_secs_f32(1.0 / 60.0);
-        prev_frame
+        fps_counter += 1;
+        let elapsed = fps_start.elapsed().as_secs_f32();
+        if elapsed >= 1.0 {
+            println!("{:.1} fps", fps_counter as f32 / elapsed);
+            fps_start = Instant::now();
+            fps_counter = 0;
+        }
+        Instant::now()
     });
 }