Fixed an issue where slop doesn't know where the shaders are located, by adding another CMake variable and fixed refract fragment shader.

CMakeLists.txt

 
 project( "slop" )
 set( slop_VERSION_MAJOR 4 )
-set( slop_VERSION_MINOR 2 )
+set( slop_VERSION_MINOR 3 )
 set( slop_VERSION_PATCH 20 )
 
 set( CMAKE_OPENGL_SUPPORT FALSE CACHE BOOL "Whether or not to compile with OpenGL, shaders, magnification, and theming support." )
    set( CMAKE_INSTALL_PREFIX "/usr" )
 endif()
 
+if( NOT INSTALL_PREFIX )
+   set( INSTALL_PREFIX "${CMAKE_INSTALL_PREFIX}" CACHE PATH "The path where slop thinks it resides in, so that it can find the shaders. This is not necessarily the CMAKE_INSTALL_PREFIX. For example if the shaders will exist in /usr/share/slop, INSTALL_PREFIX should be \"/usr\"." )
+endif()
+
 if( NOT CMAKE_CONFIGURATION_TYPES AND NOT CMAKE_BUILD_TYPE )
    set( CMAKE_BUILD_TYPE RelWithDebInfo )
 endif()
 install( TARGETS ${BIN_TARGET}
          DESTINATION "${CMAKE_INSTALL_PREFIX}/bin" )
 
-add_definitions(-DINSTALL_PREFIX="${CMAKE_INSTALL_PREFIX}")
+add_definitions(-DINSTALL_PREFIX="${INSTALL_PREFIX}")
 
 if( CMAKE_OPENGL_SUPPORT )
     install( DIRECTORY "${CMAKE_SOURCE_DIR}/share"

README.md

 help
 ----
 ```text
-slop v4.2.20
+slop v4.3.20
 
 Copyright (C) 2014 Dalton Nell, Slop Contributors
 (https://github.com/naelstrof/slop/graphs/contributors)

share/slop/refract.frag

     vec2 offset = (p/len)*cos(len*12.0-time*4.0)*0.005;
 
     // Incremental Gaussian Coefficent Calculation (See GPU Gems 3 pp. 877 - 889)
+    float blurSize = 1.f/desktopWidth*blurMultiplier;
+    vec2 blurMultiplyVec      = vec2(0.0f, 1.0f);
     vec3 incrementalGaussian;
     incrementalGaussian.x = 1.0f / (sqrt(2.0f * pi) * sigma);
     incrementalGaussian.y = exp(-0.5f / (sigma * sigma));