From 9127d8dc51de2d693e4ed1561c473166409d5fdc Mon Sep 17 00:00:00 2001
From: Laurenz Stampfl <laurenz.stampfl+github@gmail.com>
Date: Wed, 30 Sep 2026 13:21:10 +0200
Subject: [PATCH] vello_common: Exercise image sampling in probe

---
 vello_common/assets/probe_image_bilinear.png  | Bin 82 -> 138 bytes
 vello_common/assets/probe_image_bilinear.rgba | Bin 784 -> 784 bytes
 vello_common/assets/probe_image_nearest.png   | Bin 82 -> 87 bytes
 vello_common/assets/probe_image_nearest.rgba  | Bin 784 -> 784 bytes
 vello_common/src/probe.rs                     |  32 ++++++++----------
 5 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/vello_common/assets/probe_image_bilinear.png b/vello_common/assets/probe_image_bilinear.png
index 8b6fc59cd0577e6afffafdd10fc68c7d29ae549f..9769a32c8bfab7eeb74714119a3602e2b3bf550d 100644
GIT binary patch
delta 120
zcmWIQVw@mR#KO$L!0<NB;1Q6L2=EDU{SO2T467JI3mN)C8CF>`9Ft*q%)szpY_<Ab
zpc-9I7srr_TgeTK---k@94@3P>aBa}u<MG4r=^U?bPX=9osSnKzIyQM!rA6XW`^Ww
WiR;}jqz?l%GI+ZBxvX<aXaWH3^(=}2

delta 64
zcmeBT44NQe#lghDz%W5;R~wL$^mK6yskoK=!`~!<L70c-;)+X&Yo`2o!o<M1PV0%_
S(uqbuMGT&<elF{r5}E*TF%+Z#

diff --git a/vello_common/assets/probe_image_bilinear.rgba b/vello_common/assets/probe_image_bilinear.rgba
index 1815fe206614d7ef0d904ff339be49d4f46c089b..3b489753a25420b713e3e2e176f78729623ec586 100644
GIT binary patch
literal 784
zcmezWpM1c;@c%z47-kbGdO&Jn0H#ld;qiY<hGYLj8CIcSkQhh~rVd>nNWPGv@Bb=>
wP!tRj1Igji2eJpG2d)6B5F`eY8|wPV4Ht6b0Ty0_X!Q6aq#h;@(?<>s0N1?kAOHXW

delta 40
ZcmbQhHi2z|%|z?Ui8U6u(Bw5t$pA^x5KjOA

diff --git a/vello_common/assets/probe_image_nearest.png b/vello_common/assets/probe_image_nearest.png
index 8b6fc59cd0577e6afffafdd10fc68c7d29ae549f..b4bde15d9e0528b9d96c282226588441c5c10fb9 100644
GIT binary patch
delta 56
zcmWFvpP*ta=jq}YQgJK!hrdYzLn2#Kho6_>)E<VV%<`;9)WsRJ%C(+Mcr37o0SG)@
L{an^LB{Ts57E}^y

delta 51
zcmWF!nxLX5>FMGaQgJK!hrdYzgD?-v#TAzl*G&2Ggo%N1oz@e<r4x-9fWXt$&t;uc
GLK6V!a}sO-

diff --git a/vello_common/assets/probe_image_nearest.rgba b/vello_common/assets/probe_image_nearest.rgba
index 1815fe206614d7ef0d904ff339be49d4f46c089b..48832d80d8e73d08a4b7dd1835b1aeeb2c828d18 100644
GIT binary patch
literal 784
zcmezWpM1c;@c%z47-kbGdO&JnfExO6IT+b&Z1#=ngM|udaZc^{Lyjk0Y=lcmX8{1$
CyzU?X

delta 25
bcmbQhHi2z|%|z?1lO34mOwM5{fa1jfdL9XJ

diff --git a/vello_common/src/probe.rs b/vello_common/src/probe.rs
index ff1c2e058..72e8158cd 100644
--- a/vello_common/src/probe.rs
+++ b/vello_common/src/probe.rs
@@ -4,7 +4,7 @@
 //! Helpers for performing probing to verify the basic capabilities of the device we are
 //! running on.
 
-use crate::color::{AlphaColor, palette::css};
+use crate::color::palette::css;
 use crate::filter_effects::{EdgeMode, Filter, FilterPrimitive};
 #[cfg(not(feature = "std"))]
 use crate::kurbo::common::FloatFuncs as _;
@@ -28,7 +28,7 @@ const ANTI_ALIASED_RECT_SIZE: f64 = RECT_SIZE - 1.0;
 const TRANSFORMED_RECT_SIZE: f64 = RECT_SIZE / core::f64::consts::SQRT_2;
 const CIRCLE_CENTER_OFFSET_X: f64 = 1.5;
 const CIRCLE_RADIUS: f64 = RECT_SIZE * 0.5 - CIRCLE_CENTER_OFFSET_X;
-const IMAGE_SOURCE_SIZE: f64 = 5.0;
+const IMAGE_SOURCE_SIZE: f64 = 4.0;
 const PATH_TOLERANCE: f64 = 0.1;
 
 /// All elements available for use in a probe.
@@ -297,13 +297,12 @@ pub fn probe_image_pixmap() -> Pixmap {
     let mut pixmap = Pixmap::new(IMAGE_SOURCE_SIZE as u16, IMAGE_SOURCE_SIZE as u16);
     for y in 0..pixmap.height() {
         for x in 0..pixmap.width() {
-            pixmap.set_pixel(
-                x,
-                y,
-                AlphaColor::from_rgba8(255, 0, 0, 255)
-                    .premultiply()
-                    .to_rgba8(),
-            );
+            let color = if (1..3).contains(&x) && (1..3).contains(&y) {
+                css::RED
+            } else {
+                css::BLUE
+            };
+            pixmap.set_pixel(x, y, color.premultiply().to_rgba8());
         }
     }
     pixmap.set_may_have_transparency(false);
@@ -381,11 +380,11 @@ fn draw_probe_element(
             ctx.set_paint(linear_gradient(&rect).into());
             ctx.fill_rect(&rect);
         }
-        ProbeFeature::ImageNearest => draw_centered_padded_image(ctx, cell, image_nearest),
+        ProbeFeature::ImageNearest => draw_centered_image(ctx, cell, image_nearest),
         ProbeFeature::Filter => {
             draw_blurred_rect(ctx, centered_rect(cell, 10.0, 10.0));
         }
-        ProbeFeature::ImageBilinear => draw_centered_padded_image(ctx, cell, image_bilinear),
+        ProbeFeature::ImageBilinear => draw_centered_image(ctx, cell, image_bilinear),
         ProbeFeature::OpacityLayer => {
             draw_opacity_layer_rect(ctx, centered_rect(cell, RECT_SIZE, RECT_SIZE));
         }
@@ -404,14 +403,13 @@ fn centered_rect(cell: Rect, width: f64, height: f64) -> Rect {
     )
 }
 
-fn draw_centered_padded_image(ctx: &mut impl ProbeRenderer, cell: Rect, image_paint: &PaintType) {
+fn draw_centered_image(ctx: &mut impl ProbeRenderer, cell: Rect, image_paint: &PaintType) {
     let dst_rect = centered_rect(cell, RECT_SIZE, RECT_SIZE);
-    let image_origin = (
-        dst_rect.x0 + (RECT_SIZE - IMAGE_SOURCE_SIZE) * 0.5,
-        dst_rect.y0 + (RECT_SIZE - IMAGE_SOURCE_SIZE) * 0.5,
-    );
     ctx.set_paint(image_paint.clone());
-    ctx.set_paint_transform(Affine::translate(image_origin));
+    ctx.set_paint_transform(
+        Affine::translate((dst_rect.x0, dst_rect.y0))
+            * Affine::scale(RECT_SIZE / IMAGE_SOURCE_SIZE),
+    );
     ctx.fill_rect(&dst_rect);
     ctx.reset_paint_transform();
 }