From 9ec8553cf868ad062b767d1eb7105d548bf404b4 Mon Sep 17 00:00:00 2001
From: Stephen Gutekanst <stephen@hexops.com>
Date: Thu, 21 Apr 2022 04:23:09 -0700
Subject: [PATCH] examples: texture-light: more instances, rotate camera by
 default, make movement independent of frame-rate

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
---
 examples/texture-light/main.zig | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/examples/texture-light/main.zig b/examples/texture-light/main.zig
index 7c35e026..04d216a1 100755
--- a/examples/texture-light/main.zig
+++ b/examples/texture-light/main.zig
@@ -86,7 +86,7 @@ fn frame(app: *App, params: *FrameParams) !void {
     }
 
     // move camera
-    const speed = zm.f32x4s(0.2);
+    const speed = zm.f32x4s(@floatCast(f32, app.delta_time * 5));
     const fwd = zm.normalize3(params.camera.target - params.camera.eye);
     const right = zm.normalize3(zm.cross3(fwd, params.camera.up));
 
@@ -96,16 +96,15 @@ fn frame(app: *App, params: *FrameParams) !void {
     if (params.keys & FrameParams.down != 0)
         params.camera.eye -= fwd * speed;
 
-    if (params.keys & FrameParams.right != 0)
-        params.camera.eye += right * speed;
-
-    if (params.keys & FrameParams.left != 0)
-        params.camera.eye -= right * speed;
+    if (params.keys & FrameParams.right != 0) params.camera.eye += right * speed
+    else if (params.keys & FrameParams.left != 0) params.camera.eye -= right * speed
+    else params.camera.eye += right * (speed * @Vector(4, f32){0.5, 0.5, 0.5, 0.5});
 
     params.camera.update(params.queue);
 
     // move light
-    params.light.update(params.queue);
+    const light_speed = @floatCast(f32, app.delta_time * 2.5);
+    params.light.update(params.queue, light_speed);
 
     const back_buffer_view = app.swap_chain.?.getCurrentTextureView();
     defer back_buffer_view.release();
@@ -268,7 +267,7 @@ const Cube = struct {
     instance: Buffer,
     texture: Texture,
 
-    const IPR = 10; // instances per row
+    const IPR = 20; // instances per row
     const SPACING = 2; // spacing between cubes
     const DISPLACEMENT = vec3u(IPR * SPACING / 2, 0, IPR * SPACING / 2);
 
@@ -745,10 +744,10 @@ const Light = struct {
         };
     }
 
-    fn update(self: *Self, queue: gpu.Queue) void {
+    fn update(self: *Self, queue: gpu.Queue, delta: f32) void {
         const old = self.uniform;
         const new = Light.Uniform {
-            .position = zm.qmul(zm.quatFromAxisAngle(vec3u(0, 1, 0), 0.05), old.position),
+            .position = zm.qmul(zm.quatFromAxisAngle(vec3u(0, 1, 0), delta), old.position),
             .color = old.color,
         };
         queue.writeBuffer(self.buffer.buffer, 0, Light.Uniform, &.{new});