Add TextureOptions::wrap_mode (#3954)

Exposes support in both glow and wgpu for texture wrap modes

This would be breaking for manual creations of TextureOptions but would
work with the current TextureOptions::NEAREST and LINEAR without change,
keeping those clamp to edge

I wasn't sure how best to expose the options to the user and added
consts for LINEAR_REPEAT LINEAR_MIRRORED_REPEAT NEAREST_REPEAT
NEAREST_MIRRORED_REPEAT

This does not include wrap mode clamp to border as it worked fine with
glow but with wgpu it panics due to Features
Features(ADDRESS_MODE_CLAMP_TO_BORDER) are required but not enabled on
the device, and I thought it was probably best not to try to enable that
feature, but happy to include that functionality also if that is okay to
be toggled


![image](https://github.com/emilk/egui/assets/5075747/bba71f61-a105-4e5b-b8ce-1083621eb3de)

---------

Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>

crates/epaint/src/textures.rs

@@ -156,6 +156,9 @@ pub struct TextureOptions {
 
     /// How to filter when minifying (when texels are smaller than pixels).
     pub minification: TextureFilter,
+
+    /// How to wrap the texture when the texture coordinates are outside the [0, 1] range.
+    pub wrap_mode: TextureWrapMode,
 }
 
 impl TextureOptions {
@@ -163,12 +166,42 @@ impl TextureOptions {
     pub const LINEAR: Self = Self {
         magnification: TextureFilter::Linear,
         minification: TextureFilter::Linear,
+        wrap_mode: TextureWrapMode::ClampToEdge,
     };
 
     /// Nearest magnification and minification.
     pub const NEAREST: Self = Self {
         magnification: TextureFilter::Nearest,
         minification: TextureFilter::Nearest,
+        wrap_mode: TextureWrapMode::ClampToEdge,
+    };
+
+    /// Linear magnification and minification, but with the texture repeated.
+    pub const LINEAR_REPEAT: Self = Self {
+        magnification: TextureFilter::Linear,
+        minification: TextureFilter::Linear,
+        wrap_mode: TextureWrapMode::Repeat,
+    };
+
+    /// Linear magnification and minification, but with the texture mirrored and repeated.
+    pub const LINEAR_MIRRORED_REPEAT: Self = Self {
+        magnification: TextureFilter::Linear,
+        minification: TextureFilter::Linear,
+        wrap_mode: TextureWrapMode::MirroredRepeat,
+    };
+
+    /// Nearest magnification and minification, but with the texture repeated.
+    pub const NEAREST_REPEAT: Self = Self {
+        magnification: TextureFilter::Nearest,
+        minification: TextureFilter::Nearest,
+        wrap_mode: TextureWrapMode::Repeat,
+    };
+
+    /// Nearest magnification and minification, but with the texture mirrored and repeated.
+    pub const NEAREST_MIRRORED_REPEAT: Self = Self {
+        magnification: TextureFilter::Nearest,
+        minification: TextureFilter::Nearest,
+        wrap_mode: TextureWrapMode::MirroredRepeat,
     };
 }
 
@@ -193,6 +226,23 @@ pub enum TextureFilter {
     Linear,
 }
 
+/// Defines how textures are wrapped around objects when texture coordinates fall outside the [0, 1] range.
+#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, Hash)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+pub enum TextureWrapMode {
+    /// Stretches the edge pixels to fill beyond the texture's bounds.
+    ///
+    /// This is what you want to use for a normal image in a GUI.
+    #[default]
+    ClampToEdge,
+
+    /// Tiles the texture across the surface, repeating it horizontally and vertically.
+    Repeat,
+
+    /// Mirrors the texture with each repetition, creating symmetrical tiling.
+    MirroredRepeat,
+}
+
 // ----------------------------------------------------------------------------
 
 /// What has been allocated and freed during the last period.