feat(cnn_v3/tools): zoom canvas shows region around clicked texel

1 files changed, 14 insertions, 6 deletions

diff --git a/cnn_v3/tools/shaders.js b/cnn_v3/tools/shaders.js
index a1b2929..f178637 100644
--- a/cnn_v3/tools/shaders.js
+++ b/cnn_v3/tools/shaders.js
@@ -223,32 +223,40 @@ const DISP_SHADER=`
 }`;
 
 // Viz f32: show one channel of rgba16float layer
+// Uniform layout: ch(u32) _p(u32) ox(i32) oy(i32) — 16 bytes
+// ox/oy = texel offset (top-left of view); 0,0 for full-texture vignettes.
 const VIZ_F32=`
+struct Vu{ch:u32,_p:u32,ox:i32,oy:i32}
 @group(0) @binding(0) var t:texture_2d<f32>;
-@group(0) @binding(1) var<uniform> ch:u32;
+@group(0) @binding(1) var<uniform> u:Vu;
 @vertex fn vs(@builtin(vertex_index) i:u32)->@builtin(position) vec4f{
   var p=array<vec2f,6>(vec2f(-1.,-1.),vec2f(1.,-1.),vec2f(-1.,1.),vec2f(-1.,1.),vec2f(1.,-1.),vec2f(1.,1.));
   return vec4f(p[i],0.,1.);
 }
 @fragment fn fs(@builtin(position) pos:vec4f)->@location(0) vec4f{
-  let v=textureLoad(t,vec2i(pos.xy),0); var a=array<f32,4>(v.x,v.y,v.z,v.w);
-  let x=clamp(a[min(ch,3u)],0.,1.); return vec4f(x,x,x,1.);
+  let dim=vec2i(textureDimensions(t));
+  let tc=clamp(vec2i(i32(pos.x)+u.ox,i32(pos.y)+u.oy),vec2i(0),dim-vec2i(1));
+  let v=textureLoad(t,tc,0); var a=array<f32,4>(v.x,v.y,v.z,v.w);
+  let x=clamp(a[min(u.ch,3u)],0.,1.); return vec4f(x,x,x,1.);
 }`;
 
 // Viz u32: show one f16 channel of rgba32uint layer (8 channels packed)
 const VIZ_U32=`
+struct Vu{ch:u32,_p:u32,ox:i32,oy:i32}
 @group(0) @binding(0) var t:texture_2d<u32>;
-@group(0) @binding(1) var<uniform> ch:u32;
+@group(0) @binding(1) var<uniform> u:Vu;
 @vertex fn vs(@builtin(vertex_index) i:u32)->@builtin(position) vec4f{
   var p=array<vec2f,6>(vec2f(-1.,-1.),vec2f(1.,-1.),vec2f(-1.,1.),vec2f(-1.,1.),vec2f(1.,-1.),vec2f(1.,1.));
   return vec4f(p[i],0.,1.);
 }
 @fragment fn fs(@builtin(position) pos:vec4f)->@location(0) vec4f{
-  let t2=textureLoad(t,vec2i(pos.xy),0);
+  let dim=vec2i(textureDimensions(t));
+  let tc=clamp(vec2i(i32(pos.x)+u.ox,i32(pos.y)+u.oy),vec2i(0),dim-vec2i(1));
+  let t2=textureLoad(t,tc,0);
   let a=unpack2x16float(t2.x);let b=unpack2x16float(t2.y);
   let c=unpack2x16float(t2.z);let d=unpack2x16float(t2.w);
   var v=array<f32,8>(a.x,a.y,b.x,b.y,c.x,c.y,d.x,d.y);
-  let x=clamp(v[min(ch,7u)],0.,1.); return vec4f(x,x,x,1.);
+  let x=clamp(v[min(u.ch,7u)],0.,1.); return vec4f(x,x,x,1.);
 }`;
 
 // Full G-buffer pack: assembles feat_tex0/feat_tex1 from individual G-buffer images.