Minor optimization of ImFontAtlasBuildMultiplyRectAlpha8() + README tweaks.

docs/README.md

@@ -9,7 +9,7 @@ Dear ImGui
 
 <sub>(This library is available under a free and permissive license, but needs financial support to sustain its continued improvements. In addition to maintenance and stability there are many desirable features yet to be added. If your company is using Dear ImGui, please consider reaching out.)</sub>
 
-Businesses: support continued development and maintenance via invoiced technical support, maintenance, sponsoring contracts:
+Businesses: support continued development and maintenance via invoiced sponsoring/support contracts:
 <br>&nbsp;&nbsp;_E-mail: contact @ dearimgui dot com_
 <br>Individuals: support continued development and maintenance [here](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=WGHNC6MBFLZ2S). Also see [Sponsors](https://github.com/ocornut/imgui/wiki/Sponsors) page.
 
@@ -35,13 +35,11 @@ Dear ImGui is particularly suited to integration in game engines (for tooling),
  - Easy to hack and improve.
  - Portable, minimize dependencies, run on target (consoles, phones, etc.).
  - Efficient runtime and memory consumption.
- - Battle-tested, used by many major actors in the game industry.
+ - Battle-tested, used by [many major actors in the game industry](https://github.com/ocornut/imgui/wiki/Software-using-dear-imgui).
 
 ### Usage
 
-**The core of Dear ImGui is self-contained within a few platform-agnostic files** which you can easily compile in your application/engine. They are all the files in the root folder of the repository (imgui*.cpp, imgui*.h).
+**The core of Dear ImGui is self-contained within a few platform-agnostic files** which you can easily compile in your application/engine. They are all the files in the root folder of the repository (imgui*.cpp, imgui*.h). **No specific build process is required**. You can add the .cpp files into your existing project.
-
-**No specific build process is required**. You can add the .cpp files into your existing project.
 
 **Backends for a variety of graphics API and rendering platforms** are provided in the [backends/](https://github.com/ocornut/imgui/tree/master/backends) folder, along with example applications in the [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder. See the [Integration](#integration) section of this document for details. You may also create your own backend. Anywhere where you can render textured triangles, you can render Dear ImGui.
 
@@ -107,9 +105,9 @@ Reading the changelogs is a good way to keep up to date with the things Dear ImG
 
 ### Demo
 
-Calling the `ImGui::ShowDemoWindow()` function will create a demo window showcasing a variety of features and examples. The code is always available for reference in `imgui_demo.cpp`. [Here's how te demo look](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v167/v167-misc.png).
+Calling the `ImGui::ShowDemoWindow()` function will create a demo window showcasing a variety of features and examples. The code is always available for reference in `imgui_demo.cpp`. [Here's how the demo looks](https://raw.githubusercontent.com/wiki/ocornut/imgui/web/v167/v167-misc.png).
 
-You should be able to build the examples from sources (tested on Windows/Mac/Linux). If you don't, let us know! If you want to have a quick look at some Dear ImGui features, you can download Windows binaries of the demo app here:
+You should be able to build the examples from sources. If you don't, let us know! If you want to have a quick look at some Dear ImGui features, you can download Windows binaries of the demo app here:
 - [imgui-demo-binaries-20220504.zip](https://www.dearimgui.org/binaries/imgui-demo-binaries-20220504.zip) (Windows, 1.88 WIP, built 2022/05/04, master) or [older binaries](https://www.dearimgui.org/binaries).
 
 The demo applications are not DPI aware so expect some blurriness on a 4K screen. For DPI awareness in your application, you can load/reload your font at a different scale and scale your style with `style.ScaleAllSizes()` (see [FAQ](https://www.dearimgui.org/faq)).
@@ -118,7 +116,7 @@ The demo applications are not DPI aware so expect some blurriness on a 4K screen
 
 On most platforms and when using C++, **you should be able to use a combination of the [imgui_impl_xxxx](https://github.com/ocornut/imgui/tree/master/backends) backends without modification** (e.g. `imgui_impl_win32.cpp` + `imgui_impl_dx11.cpp`). If your engine supports multiple platforms, consider using more imgui_impl_xxxx files instead of rewriting them: this will be less work for you, and you can get Dear ImGui running immediately. You can _later_ decide to rewrite a custom backend using your custom engine functions if you wish so.
 
-Integrating Dear ImGui within your custom engine is a matter of 1) wiring mouse/keyboard/gamepad inputs 2) uploading one texture to your GPU/render engine 3) providing a render function that can bind textures and render textured triangles. The [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder is populated with applications doing just that. If you are an experienced programmer at ease with those concepts, it should take you less than two hours to integrate Dear ImGui into your custom engine. **Make sure to spend time reading the [FAQ](https://www.dearimgui.org/faq), comments, and the examples applications!**
+Integrating Dear ImGui within your custom engine is a matter of 1) wiring mouse/keyboard/gamepad inputs 2) uploading a texture to your GPU/render engine 3) providing a render function that can bind textures and render textured triangles. The [examples/](https://github.com/ocornut/imgui/tree/master/examples) folder is populated with applications doing just that. If you are an experienced programmer at ease with those concepts, it should take you less than two hours to integrate Dear ImGui into your custom engine. **Make sure to spend time reading the [FAQ](https://www.dearimgui.org/faq), comments, and the examples applications!**
 
 Officially maintained backends/bindings (in repository):
 - Renderers: DirectX9, DirectX10, DirectX11, DirectX12, Metal, OpenGL/ES/ES2, SDL_Renderer, Vulkan, WebGPU.
@@ -176,7 +174,7 @@ How to help
 - See [GitHub Forum/Issues](https://github.com/ocornut/imgui/issues) and [GitHub Discussions](https://github.com/ocornut/imgui/discussions).
 - You may help with development and submit pull requests! Please understand that by submitting a PR you are also submitting a request for the maintainer to review your code and then take over its maintenance forever. PR should be crafted both in the interest of the end-users and also to ease the maintainer into understanding and accepting it.
 - See [Help wanted](https://github.com/ocornut/imgui/wiki/Help-Wanted) on the [Wiki](https://github.com/ocornut/imgui/wiki/) for some more ideas.
-- Have your company financially support this project (please reach out by e-mail to say hi!).
+- Have your company financially support this project with invoiced sponsoring/support contact (please reach out: contact at dearimgui dot com).
 
 Sponsors
 --------

imgui_draw.cpp

@@ -2298,10 +2298,11 @@ void    ImFontAtlasBuildMultiplyCalcLookupTable(unsigned char out_table[256], fl
 
 void    ImFontAtlasBuildMultiplyRectAlpha8(const unsigned char table[256], unsigned char* pixels, int x, int y, int w, int h, int stride)
 {
+    IM_ASSERT_PARANOID(w <= stride);
     unsigned char* data = pixels + x + y * stride;
-    for (int j = h; j > 0; j--, data += stride)
+    for (int j = h; j > 0; j--, data += stride - w)
-        for (int i = 0; i < w; i++)
+        for (int i = w; i > 0; i--, data++)
-            data[i] = table[data[i]];
+            *data = table[*data];
 }
 
 #ifdef IMGUI_ENABLE_STB_TRUETYPE
@@ -2318,7 +2319,7 @@ struct ImFontBuildSrcData
     int                 GlyphsHighest;      // Highest requested codepoint
     int                 GlyphsCount;        // Glyph count (excluding missing glyphs and glyphs already set by an earlier source font)
     ImBitVector         GlyphsSet;          // Glyph bit map (random access, 1-bit per codepoint. This will be a maximum of 8KB)
-    ImVector<int>       GlyphsList;         // Glyph codepoints list (flattened version of GlyphsMap)
+    ImVector<int>       GlyphsList;         // Glyph codepoints list (flattened version of GlyphsSet)
 };
 
 // Temporary data for one destination ImFont* (multiple source fonts can be merged into one destination ImFont)