Detailed Description

Wrapper for using a ExprBase as GlAbstractInclude.

GlExpr provides GlAbstractInclude which can be used in a GlProgram. The GlAbstractInclude defines "EXPR" and a method with the following signature (see SharedImageSetArithmetic.glh)

vec4 exprVal(vec3 tc, vec4 varval, int index);

The index can be used in case of SharedImageSets in order to index the image you are evaluating. This class also provides setIndices() in order to choose which SharedImages of a SharedImageSet are supposed to be bound.

Example: SharedImageSetArithmetic.frag:

#version 400
in vec3 in_texCoord;
 
#ifdef EXPR_NUM_IMG
layout(location = 0) out vec4 out_color[EXPR_NUM_IMG];
#else
layout(location = 0) out vec4 out_color;
#endif
 
#pragma abstract_include "EXPR"
#ifndef EXPR
// default implementation if no definition was set
vec4 exprVal(vec3 tc, vec4 val, int index)
{
  return vec4(0.0);
}
#endif
 
void main()
{
 
  vec4 varVal = vec4(0.0);
 
#ifdef EXPR_NUM_IMG
#ifdef EXPR
  for(int i = 0; i < EXPR_NUM_IMG; ++i)
      out_color[i] = exprVal(in_texCoord, varVal, i);
#endif
#else
  out_color = exprVal(in_texCoord, varVal, 0);
#endif
}

Now in c++ any expression can be used in this shader by:

SharedImage img(...);
 
auto expr2 = ...;
GlExpr wrapper(expr2);
auto program = std::make_unique<GL::ImageProgram>("ImFusionLib/ImageMath/SharedImageSetArithmetic.frag");
program->addAbstractIncludeDefinition(&wrapper);
program->enable();
wrapper.setIncludeArguments(*program);
program->compute(*img.gl());
program->unbindImages();
program->disable();
GLCHECK;
img.setDirtyGl();

Public Member Functions
	GlExpr (const internal::GlExprInterface &expr)

std::function< std::string(const std::string &)>	includeCodeSubstitution () const override
	Replaces any occurrence of UNIFORMS_IMPL with the uniform definition and any occurrence of EXPR_IMPL with the actual expression.

int	setIncludeArguments (GL::Program &p, const std::string &prefix="expr") const override

Fingerprint	fingerprint () const override
	Provides a finger print of the include.

void	setIndices (std::vector< int > indices)
	Set the indices which shall be considered in case of a SharedImageSet ()

int	numRequiredSamplersPerIndex ()
	Returns how many samplers are required per index.

const internal::GlExprInterface &	expr () const
	Get wrapped expression.

Public Member Functions inherited from AbstractInclude
	AbstractInclude (const std::string &defineName, const std::string &includePath)
	Creates a AbstractInclude for the given define and with the corresponding GLSL file at includePath.

const std::string &	defineName () const
	Returns the name of define used by this include.

const std::string &	includePath () const
	Returns the path to the included shader file.

virtual std::vector< AbstractInclude * >	dependentIncludes () const
	Returns a list of dependent abstract includes that need to be included as well.

Public Member Functions inherited from MultiIncludable< GlExpr >
std::shared_ptr< MultiIncludeType >	createMultiInclude (const std::string &replacementToken)
	Instantiates a new AbstractInclude instance where all occurrences of baseToken provided during construction are replaces with replacementToken according to the specified replacementScheme.

virtual int	setIncludeArguments (Program &prog, IncludeArgumentsTypes... includeArgs, const std::string &token) const=0
	Interface that multi includes should use to configure the shader include (such as setting uniforms, binding textures, etc).

Static Public Member Functions
static std::string	defineName ()
	Returns "EXPR".

static std::string	defineSuffix ()
	Returns "EXPR".

Additional Inherited Members
Public Types inherited from MultiIncludable< GlExpr >
using	MultiIncludeType
	Alias for type of a multi-include instance of the original include.

Protected Member Functions inherited from MultiIncludable< GlExpr >
	MultiIncludable (GlExpr *crtpInstance, const std::string &baseToken, Flags< ShaderTextReplacement > replacementScheme)
	Instantiate and configure the MultiIncludable interface.

Member Function Documentation

◆ includeCodeSubstitution()

std::function< std::string(const std::string &)> includeCodeSubstitution ( ) const

overridevirtual

Replaces any occurrence of UNIFORMS_IMPL with the uniform definition and any occurrence of EXPR_IMPL with the actual expression.

Reimplemented from AbstractInclude.

◆ fingerprint()

Fingerprint fingerprint ( ) const

overridevirtual

Provides a finger print of the include.

If two finger prints are equal this means that the two includes provide the very same code substitution. It does NOT mean that the two includes are equal. In particular the result of setArguments can be different.

Reimplemented from AbstractInclude.

The documentation for this class was generated from the following file:

ImFusion/ImageMath/OpenGL/GlExpr.h

Detailed Description

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Member Function Documentation

◆ includeCodeSubstitution()

◆ fingerprint()