unsafety in text fix

imgui-examples/examples/custom_textures.rs

@@ -189,8 +189,8 @@ impl Lenna {
         decoder.read_image(&mut image)?;
         let raw = RawImage2d {
             data: Cow::Owned(image),
-            width: width as u32,
-            height: height as u32,
+            width,
+            height,
             format: ClientFormat::U8U8U8,
         };
         let gl_texture = Texture2d::new(gl_ctx, raw)?;

imgui-examples/examples/test_window_impl.rs

@@ -759,7 +759,7 @@ CTRL+click on individual component to input value.\n",
             );
 
             state.filter.draw();
-            let lines = vec!["aaa1.c", "bbb1.c", "ccc1.c", "aaa2.cpp", "bbb2.cpp", "ccc2.cpp", "abc.h", "hello, world!"];
+            let lines = ["aaa1.c", "bbb1.c", "ccc1.c", "aaa2.cpp", "bbb2.cpp", "ccc2.cpp", "abc.h", "hello, world!"];
 
             ui.same_line();
             if ui.button("Clear##clear_filter") {
@@ -1285,7 +1285,7 @@ fn show_app_log(ui: &Ui, app_log: &mut Vec<String>) {
             }
             ui.same_line();
             if ui.button("Copy") {
-                ui.set_clipboard_text(&ImString::from(app_log.join("\n")));
+                ui.set_clipboard_text(ImString::from(app_log.join("\n")));
             }
             ui.separator();
             ui.child_window("logwindow")

imgui-examples/examples/text_callbacks.rs

@@ -106,7 +106,7 @@ fn main() {
                                 if !data.str().is_empty() {
                                     data.remove_chars(0, 1);
 
-                                    if let Some((idx, _)) = data.str().char_indices().rev().next() {
+                                    if let Some((idx, _)) = data.str().char_indices().next_back() {
                                         data.remove_chars(idx, 1);
                                     }
                                 }
@@ -118,7 +118,7 @@ fn main() {
                                 }
 
                                 // insert last char
-                                if let Some((idx, _)) = self.1.char_indices().rev().next() {
+                                if let Some((idx, _)) = self.1.char_indices().next_back() {
                                     data.push_str(&self.1[idx..]);
                                 }
                             }

imgui-glow-renderer/src/lib.rs

@@ -1152,7 +1152,7 @@ fn calculate_matrix(draw_data: &DrawData, clip_origin_is_lower_left: bool) -> [f
 }
 
 unsafe fn to_byte_slice<T>(slice: &[T]) -> &[u8] {
-    std::slice::from_raw_parts(slice.as_ptr().cast(), slice.len() * size_of::<T>())
+    std::slice::from_raw_parts(slice.as_ptr().cast(), std::mem::size_of_val(slice))
 }
 
 const fn imgui_index_type_as_gl() -> u32 {

imgui/src/context.rs

@@ -523,7 +523,7 @@ impl Context {
         // we take this with an `&mut Self` here, which means
         // that we can't get the sharedfontatlas through safe code
         // otherwise
-        unsafe { &mut *(self.io_mut().fonts as *mut FontAtlas) }
+        unsafe { &mut *self.io_mut().fonts }
     }
 
     /// Attempts to clone the interior shared font atlas **if it exists**.

imgui/src/draw_list.rs

@@ -27,7 +27,6 @@ bitflags!(
     /// Options for some DrawList operations.
     #[repr(C)]
     pub struct DrawFlags: u32 {
-        const NONE = sys::ImDrawFlags_None;
         const CLOSED = sys::ImDrawFlags_Closed;
         const ROUND_CORNERS_TOP_LEFT = sys::ImDrawFlags_RoundCornersTopLeft;
         const ROUND_CORNERS_TOP_RIGHT = sys::ImDrawFlags_RoundCornersTopRight;
@@ -46,7 +45,6 @@ bitflags!(
     /// Draw list flags
     #[repr(C)]
     pub struct DrawListFlags: u32 {
-        const NONE = sys::ImDrawListFlags_None;
         /// Enable anti-aliased lines/borders (*2 the number of triangles for 1.0f wide line or lines
         /// thin enough to be drawn using textures, otherwise *3 the number of triangles)
         const ANTI_ALIASED_LINES = sys::ImDrawListFlags_AntiAliasedLines;

imgui/src/fonts/glyph_ranges.rs

@@ -17,10 +17,6 @@ enum FontGlyphRangeData {
 #[derive(Clone, Eq, PartialEq, Debug)]
 pub struct FontGlyphRanges(FontGlyphRangeData);
 impl FontGlyphRanges {
-    /// The default set of glyph ranges used by imgui.
-    pub fn default() -> FontGlyphRanges {
-        FontGlyphRanges(FontGlyphRangeData::Default)
-    }
     /// A set of glyph ranges appropriate for use with simplified common Chinese text.
     pub fn chinese_simplified_common() -> FontGlyphRanges {
         FontGlyphRanges(FontGlyphRangeData::ChineseSimplifiedCommon)
@@ -162,3 +158,10 @@ impl FontGlyphRanges {
         }
     }
 }
+
+impl Default for FontGlyphRanges {
+    /// The default set of glyph ranges used by imgui.
+    fn default() -> Self {
+        FontGlyphRanges(FontGlyphRangeData::Default)
+    }
+}

imgui/src/internal.rs

@@ -1,6 +1,6 @@
 //! Internal raw utilities (don't use unless you know what you're doing!)
 
-use std::{mem::size_of, slice};
+use std::slice;
 
 /// A generic version of the raw imgui-sys ImVector struct types
 #[repr(C)]
@@ -25,7 +25,7 @@ impl<T> ImVector<T> {
         unsafe {
             sys::igMemFree(self.data as *mut _);
 
-            let buffer_ptr = sys::igMemAlloc(size_of::<T>() * data.len()) as *mut T;
+            let buffer_ptr = sys::igMemAlloc(std::mem::size_of_val(data)) as *mut T;
             buffer_ptr.copy_from_nonoverlapping(data.as_ptr(), data.len());
 
             self.size = data.len() as i32;

imgui/src/lib.rs

@@ -721,9 +721,16 @@ impl Ui {
             let handle = &mut *self.scratch_buffer().get();
 
             handle.refresh_buffer();
-            let label_ptr = handle.push(label);
+            let label_start = handle.push(label);
 
-            let items_inner: Vec<_> = items.iter().map(|&v| handle.push(v)).collect();
+            // we do this in two allocations
+            let items_inner: Vec<usize> = items.iter().map(|&v| handle.push(v)).collect();
+            let items_inner: Vec<*const _> = items_inner
+                .into_iter()
+                .map(|v| handle.buffer.as_ptr().add(v) as *const _)
+                .collect();
+
+            let label_ptr = handle.buffer.as_ptr().add(label_start) as *const _;
 
             (label_ptr, items_inner)
         };

imgui/src/render/draw_data.rs

@@ -334,7 +334,7 @@ impl From<&DrawData> for OwnedDrawData {
         OwnedDrawData {
             draw_data: unsafe {
                 let other_ptr = value.raw();
-                let mut result = sys::ImDrawData_ImDrawData();
+                let result = sys::ImDrawData_ImDrawData();
                 (*result).Valid = other_ptr.Valid;
                 (*result).TotalIdxCount = other_ptr.TotalIdxCount;
                 (*result).TotalVtxCount = other_ptr.TotalVtxCount;
@@ -404,7 +404,7 @@ fn test_owneddrawdata_from_drawdata() {
         DisplaySize: sys::ImVec2 { x: 789.0, y: 012.0 },
         FramebufferScale: sys::ImVec2 { x: 3.0, y: 7.0 },
         #[cfg(feature = "docking")]
-        OwnerViewport: unsafe { (std::ptr::null_mut() as *mut sys::ImGuiViewport).offset(123) },
+        OwnerViewport: unsafe { std::ptr::null_mut::<sys::ImGuiViewport>().offset(123) },
     };
     let draw_data = unsafe { DrawData::from_raw(&draw_data_raw) };
 

imgui/src/string.rs

@@ -24,7 +24,9 @@ impl UiBuffer {
     /// Internal method to push a single text to our scratch buffer.
     pub fn scratch_txt(&mut self, txt: impl AsRef<str>) -> *const sys::cty::c_char {
         self.refresh_buffer();
-        self.push(txt)
+
+        let start_of_substr = self.push(txt);
+        unsafe { self.offset(start_of_substr) }
     }
 
     /// Internal method to push an option text to our scratch buffer.
@@ -42,7 +44,11 @@ impl UiBuffer {
         txt_1: impl AsRef<str>,
     ) -> (*const sys::cty::c_char, *const sys::cty::c_char) {
         self.refresh_buffer();
-        (self.push(txt_0), self.push(txt_1))
+
+        let first_offset = self.push(txt_0);
+        let second_offset = self.push(txt_1);
+
+        unsafe { (self.offset(first_offset), self.offset(second_offset)) }
     }
 
     /// Helper method, same as [`Self::scratch_txt`] but with one optional value
@@ -58,21 +64,30 @@ impl UiBuffer {
     }
 
     /// Attempts to clear the buffer if it's over the maximum length allowed.
+    /// This is to prevent us from making a giant vec over time.
     pub fn refresh_buffer(&mut self) {
         if self.buffer.len() > self.max_len {
             self.buffer.clear();
         }
     }
 
-    /// Pushes a new scratch sheet text, which means it's not handling any clearing at all.
-    pub fn push(&mut self, txt: impl AsRef<str>) -> *const sys::cty::c_char {
-        unsafe {
-            let len = self.buffer.len();
-            self.buffer.extend(txt.as_ref().as_bytes());
-            self.buffer.push(b'\0');
+    /// Given a position, gives an offset from the start of the scatch buffer.
+    ///
+    /// # Safety
+    /// This can return a pointer to undefined data if given a `pos >= self.buffer.len()`.
+    /// This is marked as unsafe to reflect that.
+    pub unsafe fn offset(&self, pos: usize) -> *const sys::cty::c_char {
+        self.buffer.as_ptr().add(pos) as *const _
+    }
 
-            self.buffer.as_ptr().add(len) as *const _
-        }
+    /// Pushes a new scratch sheet text and return the byte index where the sub-string
+    /// starts.
+    pub fn push(&mut self, txt: impl AsRef<str>) -> usize {
+        let len = self.buffer.len();
+        self.buffer.extend(txt.as_ref().as_bytes());
+        self.buffer.push(b'\0');
+
+        len
     }
 }
 

imgui/src/widget/drag.rs

@@ -209,22 +209,22 @@ where
     /// Returns true if the slider value was changed.
     #[doc(alias = "DragFloatRange2")]
     pub fn build(self, ui: &Ui, min: &mut f32, max: &mut f32) -> bool {
-        let label;
-        let mut display_format = std::ptr::null();
-        let mut max_display_format = std::ptr::null();
-
         // we do this ourselves the long way...
         unsafe {
             let buffer = &mut *ui.scratch_buffer().get();
             buffer.refresh_buffer();
 
-            label = buffer.push(self.label);
-            if let Some(v) = self.display_format {
-                display_format = buffer.push(v);
-            }
-            if let Some(v) = self.max_display_format {
-                max_display_format = buffer.push(v);
-            }
+            let label_start = buffer.push(self.label);
+            let display_format = self.display_format.as_ref().map(|v| buffer.push(v));
+            let max_display_format = self.max_display_format.as_ref().map(|v| buffer.push(v));
+
+            let label = buffer.offset(label_start);
+            let display_format = display_format
+                .map(|v| buffer.offset(v))
+                .unwrap_or_else(std::ptr::null);
+            let max_display_format = max_display_format
+                .map(|v| buffer.offset(v))
+                .unwrap_or_else(std::ptr::null);
 
             sys::igDragFloatRange2(
                 label,
@@ -253,20 +253,21 @@ where
     #[doc(alias = "DragIntRange2")]
     pub fn build(self, ui: &Ui, min: &mut i32, max: &mut i32) -> bool {
         unsafe {
-            let mut display_format = std::ptr::null();
-            let mut max_display_format = std::ptr::null();
-
             // we do this ourselves the long way...
             let buffer = &mut *ui.scratch_buffer().get();
             buffer.refresh_buffer();
 
-            let label = buffer.push(self.label);
-            if let Some(v) = self.display_format {
-                display_format = buffer.push(v);
-            }
-            if let Some(v) = self.max_display_format {
-                max_display_format = buffer.push(v);
-            }
+            let label_start = buffer.push(self.label);
+            let display_format = self.display_format.as_ref().map(|v| buffer.push(v));
+            let max_display_format = self.max_display_format.as_ref().map(|v| buffer.push(v));
+
+            let label = buffer.offset(label_start);
+            let display_format = display_format
+                .map(|v| buffer.offset(v))
+                .unwrap_or_else(std::ptr::null);
+            let max_display_format = max_display_format
+                .map(|v| buffer.offset(v))
+                .unwrap_or_else(std::ptr::null);
 
             sys::igDragIntRange2(
                 label,