ImGui Android Blur

Minimal OpenGL ES 3.0 blur helper for Android. Two paths:

• Hardware::GPU (fast, framebuffer ping-pong)
• Hardware::CPU (readback + CPU box blur)
• Blur::Type:
  • Default
  • Gaussian
  • Box
  • Frosted
  • Kawase
  • Bokeh
  • Motion
  • Zoom
  • Pixelate

Files

• blur.hpp
• blur.cpp
• blur/math.hpp
• blur/cpu/cpu.cpp
• blur/gpu/gpu.cpp
• blur/gpu/shaders/shaders.hpp
• demo/demo_blur.cpp
• demo/examples/imgui_examples.cpp
• demo/examples/opengl_examples.cpp

Build Notes

• If you use regular GLES headers/functions, do nothing.
• If your project uses dynamic GL function loading (for example via function pointers), build with:
  • -DBLUR_RENDERER_NO_GLES
• In this mode, blur.hpp includes:
  • #include "../good_luck/glegl/glegl.h"
• Replace that include with your own GL loader header path if needed.
• If you use ImGui overloads (ImDrawList, ImRect, ImVec2 variants), make sure imgui.h is available in include paths.

Add To Your Project

1. Add sources to build:
   • imgui-android-blur/blur.cpp
   • imgui-android-blur/blur/cpu/cpu.cpp
   • imgui-android-blur/blur/gpu/gpu.cpp
2. Add include path(s):
   • imgui-android-blur
   • your ImGui headers path (if using ImGui overloads)
3. If you use dynamic GL loading, add compiler define:
   • -DBLUR_RENDERER_NO_GLES
4. Include and use in render loop:

#include "../imgui-android-blur/blur.hpp"

static Blur* blur = nullptr;
if (!blur) {
    blur = new Blur(Hardware::GPU);
}

blur->process(x, y, w, h, 12.0f, 4);
// draw blur->tex in your renderer / ImGui draw list

This pointer-style init avoids destructor-time GL cleanup when the library is unloaded without a valid GL context.

Examples

• ImGui settings demo window: demo/demo_blur.cpp
• ImGui example: demo/examples/imgui_examples.cpp
• OpenGL ES example: demo/examples/opengl_examples.cpp

Demo Screenshot

Notes

• Coordinates for process(draw, ...) are derived from the current ImGui window.
• For ImGui, flip UVs (0,1) to (1,0) to display correctly.
• Hardware::CPU does glReadPixels and is slower.