SLTexColorLUT defines a lookup table as an 1D texture of (256) RGBA values. More...

#include <SLTexColorLUT.h>

Inheritance diagram for SLTexColorLUT:

Public Member Functions
	SLTexColorLUT (SLAssetManager *assetMgr, SLColorLUTType lutType, SLuint length=256)
	Default ctor color LUT of a specific SLColorLUTType. More...

	SLTexColorLUT (SLAssetManager *assetMgr, SLVAlphaLUTPoint alphaVec, SLColorLUTType lutType=CLUT_RYGCB, SLuint length=256)
	ctor with vector of alpha values and a predefined color LUT scheme More...

	SLTexColorLUT (SLAssetManager *assetMgr, SLVAlphaLUTPoint alphaValues, SLVColorLUTPoint colorValues, SLuint length=256)
	ctor with vector of alpha and color values More...

virtual	~SLTexColorLUT ()

void	generateTexture ()
	Generates the full 256 value LUT as 1x256 RGBA texture. More...

void	colors (SLColorLUTType lut)
	Colors setter function by predefined color LUT. More...

SLuint	length ()

SLVColorLUTPoint &	colors ()

SLVAlphaLUTPoint &	alphas ()

SLVfloat	allAlphas ()
	Returns all alpha values of the transfer function as a float vector. More...

SLVCol3f	allColors ()
	Returns all alpha values of the transfer function as a float vector. More...

Public Member Functions inherited from SLGLTexture
	SLGLTexture ()
	Default ctor for all stack instances (not created with new) More...

	SLGLTexture (SLAssetManager *assetMgr, const SLVCol4f &colors, SLint min_filter=GL_LINEAR, SLint mag_filter=GL_LINEAR, SLint wrapS=GL_REPEAT, const SLstring &name="2D-Texture")
	ctor for 1D texture with internal image allocation More...

	SLGLTexture (SLAssetManager *assetMgr, SLint min_filter, SLint mag_filter, SLint wrapS, SLint wrapT, SLenum target=GL_TEXTURE_2D)
	ctor for empty 2D textures More...

	SLGLTexture (SLAssetManager assetMgr, unsigned char data, int width, int height, int cvtype, SLint min_filter, SLint mag_filter, SLTextureType type, SLint wrapS, SLint wrapT)
	ctor for 2D textures from byte pointer More...

	SLGLTexture (SLAssetManager *assetMgr, const SLstring &imageFilename, SLint min_filter=GL_LINEAR_MIPMAP_LINEAR, SLint mag_filter=GL_LINEAR, SLTextureType type=TT_unknown, SLint wrapS=GL_REPEAT, SLint wrapT=GL_REPEAT)
	ctor for 2D textures with internal image allocation More...

	SLGLTexture (SLAssetManager *assetMgr, const SLVstring &imageFilenames, SLint min_filter=GL_LINEAR, SLint mag_filter=GL_LINEAR, SLint wrapS=GL_REPEAT, SLint wrapT=GL_REPEAT, const SLstring &name="3D-Texture", SLbool loadGrayscaleIntoAlpha=false)
	ctor for 3D texture with internal image allocation More...

	SLGLTexture (SLAssetManager *assetMgr, SLint depth, const SLstring &imageFilename, SLint min_filter=GL_LINEAR, SLint mag_filter=GL_LINEAR, SLint wrapS=GL_REPEAT, SLint wrapT=GL_REPEAT, const SLstring &name="3D-Texture", SLbool loadGrayscaleIntoAlpha=false)
	ctor for 3D texture from a single file with depth as 3rd dimension More...

	SLGLTexture (SLAssetManager *assetMgr, const SLstring &imageFilenameXPos, const SLstring &imageFilenameXNeg, const SLstring &imageFilenameYPos, const SLstring &imageFilenameYNeg, const SLstring &imageFilenameZPos, const SLstring &imageFilenameZNeg, SLint min_filter=GL_LINEAR, SLint mag_filter=GL_LINEAR, SLTextureType type=TT_unknown)
	ctor for cube mapping with internal image allocation More...

	~SLGLTexture () override

virtual void	build (SLint texUnit)

void	deleteData (SLbool deleteAlsoOnGPU)
	Delete all data (CVImages and GPU textures) More...

void	deleteDataGpu ()
	Deletes the OpenGL texture objects and releases the memory on the GPU. More...

void	deleteImages ()
	Deletes the CVImages in _images. No more texture mapping in ray tracing. More...

void	bindActive (SLuint texUnit=0)

void	fullUpdate ()

void	drawSprite (SLbool doUpdate, SLfloat x, SLfloat y, SLfloat w, SLfloat h)
	Draws the texture as 2D sprite with OpenGL buffers. More...

void	cubeUV2XYZ (SLint index, SLfloat u, SLfloat v, SLfloat &x, SLfloat &y, SLfloat &z)
	Computes the unnormalised vector x,y,z from tex. coords. uv with cubemap index. More...

void	cubeXYZ2UV (SLfloat x, SLfloat y, SLfloat z, SLint &index, SLfloat &u, SLfloat &v)
	Computes the uv and cubemap image index from a unnormalised vector x,y,z. More...

SLstring	filterString (SLint glFilter)
	Returns OpenGL texture filter as string. More...

void	texType (SLTextureType bt)

void	uvIndex (SLbyte i)

void	bumpScale (SLfloat bs)

void	minFiler (SLint minF)

void	magFiler (SLint magF)

void	needsUpdate (SLbool update)

void	textureSize (int width, int height)

void	deleteImageAfterBuild (SLbool delImg)
	If deleteImageAfterBuild is set to true you won't be able to ray trace the scene. More...

SLuint	width ()

SLuint	height ()

SLuint	depth ()

SLbyte	uvIndex ()

SLint	bytesPerPixel ()

SLint	bytesOnGPU ()

SLint	bytesInFile ()

CVVImage &	images ()

SLenum	target () const

SLuint	texID () const

SLTextureType	texType ()

SLfloat	bumpScale () const

SLCol4f	getTexelf (SLfloat u, SLfloat v, SLuint imgIndex=0)
	SLGLTexture::getTexelf returns a pixel color from u & v texture coordinates. More...

SLCol4f	getTexelf (const SLVec3f &cubemapDir)
	SLGLTexture::getTexelf returns a pixel color at the specified cubemap direction. More...

SLbool	hasAlpha ()

SLMat4f	tm ()

SLbool	autoCalcTM3D () const

SLbool	needsUpdate ()

SLstring	typeName ()
	Returns the texture type as string. More...

SLstring	typeShortName ()
	Returns the texture type short. More...

bool	isTexture ()

SLstring	minificationFilterName ()

SLstring	magnificationFilterName ()

void	build2DMipmaps (SLint target, SLuint index)

SLbool	copyVideoImage (SLint camWidth, SLint camHeight, CVPixelFormatGL glFormat, SLuchar *data, SLbool isContinuous, SLbool isTopLeft)
	Copies the image data from a video camera into the current video image. More...

SLbool	copyVideoImage (SLint camWidth, SLint camHeight, CVPixelFormatGL srcFormat, CVPixelFormatGL dstFormat, SLuchar *data, SLbool isContinuous, SLbool isTopLeft)

void	calc3DGradients (SLint sampleRadius, const function< void(int)> &onUpdateProgress=nullptr)

void	smooth3DGradients (SLint smoothRadius, function< void(int)> onUpdateProgress=nullptr)

SLVec2f	dudv (SLfloat u, SLfloat v)

Public Member Functions inherited from SLObject
	SLObject (const SLstring &Name="", const SLstring &url="")

virtual	~SLObject ()

void	name (const SLstring &Name)

void	url (const SLstring &url)

const SLstring &	name () const

const SLstring &	url () const

Public Member Functions inherited from SLEventHandler
	SLEventHandler ()

virtual	~SLEventHandler ()

virtual SLbool	onMouseDown (const SLMouseButton button, const SLint x, const SLint y, const SLKey mod)

virtual SLbool	onMouseUp (const SLMouseButton button, const SLint x, const SLint y, const SLKey mod)

virtual SLbool	onMouseMove (const SLMouseButton button, const SLint x, const SLint y, const SLKey mod)

virtual SLbool	onDoubleClick (const SLMouseButton button, const SLint x, const SLint y, const SLKey mod)

virtual SLbool	onMouseWheel (const SLint delta, const SLKey mod)

virtual SLbool	onTouch2Down (const SLint x1, const SLint y1, const SLint x2, const SLint y2)

virtual SLbool	onTouch2Move (const SLint x1, const SLint y1, const SLint x2, const SLint y2)

virtual SLbool	onTouch2Up (const SLint x1, const SLint y1, const SLint x2, const SLint y2)

virtual SLbool	onTouch3Down (const SLint x1, const SLint y1)

virtual SLbool	onTouch3Move (const SLint x1, const SLint y1)

virtual SLbool	onTouch3Up (const SLint x1, const SLint y1)

virtual SLbool	onKeyPress (const SLKey key, const SLKey mod)

virtual SLbool	onKeyRelease (const SLKey key, const SLKey mod)

virtual SLbool	onRotationPYR (const SLfloat pitchRAD, const SLfloat yawRAD, const SLfloat rollRAD)

void	mouseRotationFactor (SLfloat rf)

SLfloat	mouseRotationFactor ()

Protected Attributes
SLuint	_length

SLColorLUTType	_colorLUT
	Length of transfer function (default 256) More...

SLVColorLUTPoint	_colors
	Color LUT identifier. More...

SLVAlphaLUTPoint	_alphas
	vector of colors in TF More...

Protected Attributes inherited from SLGLTexture
CVVImage	_images
	Vector of CVImage pointers. More...

SLuint	_texID
	OpenGL texture ID. More...

SLTextureType	_texType
	See SLTextureType. More...

SLint	_width
	Texture image width in pixels (images exist either in _images or on the GPU or on both) More...

SLint	_height
	Texture image height in pixels (images exist either in _images or on the GPU or on both) More...

SLint	_depth
	3D Texture image depth (images exist either in _images or on the GPU or on both) More...

SLbyte	_uvIndex
	Texture coordinate index in SLMesh (0 = default) More...

SLint	_internalFormat
	Internal OpenGL format. More...

SLint	_bytesPerPixel
	Bytes per texture image pixel (images exist either in _images or on the GPU or on both) More...

SLint	_min_filter
	Minification filter. More...

SLint	_mag_filter
	Magnification filter. More...

SLint	_wrap_s
	Wrapping in s direction. More...

SLint	_wrap_t
	Wrapping in t direction. More...

SLenum	_target
	texture target More...

SLMat4f	_tm
	texture matrix More...

SLuint	_bytesOnGPU
	NO. of bytes on GPU. More...

SLuint	_bytesInFile
	NO. of bytes in file. More...

SLbool	_autoCalcTM3D
	Flag if texture matrix should be calculated from AABB for 3D mapping. More...

SLfloat	_bumpScale
	Bump mapping scale factor. More...

SLbool	_resizeToPow2
	Flag if image should be resized to n^2. More...

SLGLVertexArray	_vaoSprite
	Vertex array object for sprite rendering. More...

std::atomic< bool >	_needsUpdate {}
	Flag if image needs an single update. More...

std::mutex	_mutex
	Mutex to protect parallel access (used in ray tracing) More...

SLbool	_deleteImageAfterBuild
	Flag if images should be deleted after build on GPU. More...

SLbool	_compressedTexture = false
	True for compressed texture format on GPU. More...

Protected Attributes inherited from SLObject
SLstring	_name
	name of an object More...

SLstring	_url
	uniform resource locator More...

Protected Attributes inherited from SLEventHandler
SLfloat	_mouseRotationFactor
	Mouse rotation sensibility. More...

SLfloat	_keyboardDeltaPos
	Delta dist. for keyboard translation. More...

Additional Inherited Members
Static Public Member Functions inherited from SLGLTexture
static SLTextureType	detectType (const SLstring &filename)
	Detects the texture type from the filename appendix (See SLTexType def.) More...

static string	internalFormatStr (int internalFormat)
	Returns the internal pixel format from OpenGL. More...

Static Public Attributes inherited from SLGLTexture
static SLfloat	maxAnisotropy = -1.0f
	Returns the derivation as [s,t]. More...

static SLuint	totalNumBytesOnGPU = 0
	Total NO. of bytes used for textures on GPU. More...

Protected Member Functions inherited from SLGLTexture
void	load (const SLstring &filename, SLbool flipVertical=true, SLbool loadGrayscaleIntoAlpha=false)
	Loads the texture, converts color depth & applies vertical mirroring. More...

void	load (const SLVCol4f &colors)
	Loads the 1D color data into an image of height 1. More...

Detailed Description

SLTexColorLUT defines a lookup table as an 1D texture of (256) RGBA values.

SLTexColorLUT defines an RGBA color lookup table (LUT). It can be used to define a transfer function that are generated from a set of color and alpha points where all in-between points are linearly interpolated. Such a color/alpha lookup table is used as a transfer function e.g. in volume rendering (see the shader VolumeRenderingRayCast). All values (RGB color, alpha and position) are values between 0-1 and are mapped to 0-255 when the texture image of size 1x256 is generated.

Definition at line 68 of file SLTexColorLUT.h.

Constructor & Destructor Documentation

◆ SLTexColorLUT() [1/3]

SLTexColorLUT::SLTexColorLUT	(	SLAssetManager *	assetMgr,
		SLColorLUTType	lutType,
		SLuint	length = `256`
	)

Default ctor color LUT of a specific SLColorLUTType.

Definition at line 16 of file SLTexColorLUT.cpp.

 {
     _min_filter = GL_LINEAR;
     _mag_filter = GL_LINEAR;
     _wrap_s     = GL_CLAMP_TO_EDGE;
     _wrap_t     = GL_CLAMP_TO_EDGE;
     _texType    = TT_diffuse;
     _length     = length;
     _target     = GL_TEXTURE_2D; // OpenGL ES doesn't define 1D textures. We just make a 1 pixel high 2D texture
  
     colors(lutType);
  
     generateTexture();
  
     // Add pointer to the global resource vectors for deallocation
     if (assetMgr)
         assetMgr->textures().push_back(this);
 }

◆ SLTexColorLUT() [2/3]

SLTexColorLUT::SLTexColorLUT	(	SLAssetManager *	assetMgr,
		SLVAlphaLUTPoint	alphaVec,
		SLColorLUTType	lutType = `CLUT_RYGCB`,
		SLuint	length = `256`
	)

ctor with vector of alpha values and a predefined color LUT scheme

Definition at line 38 of file SLTexColorLUT.cpp.

 {
     _min_filter = GL_LINEAR;
     _mag_filter = GL_LINEAR;
     _wrap_s     = GL_CLAMP_TO_EDGE;
     _wrap_t     = GL_CLAMP_TO_EDGE;
     _texType    = TT_diffuse;
     _length     = length;
     _target     = GL_TEXTURE_2D; // OpenGL ES doesn't define 1D textures. We just make a 1 pixel high 2D texture
  
     colors(lutType);
  
     for (auto alpha : alphaValues)
         _alphas.push_back(alpha);
  
     generateTexture();
  
     // Add pointer to the global resource vectors for deallocation
     if (assetMgr)
         assetMgr->textures().push_back(this);
 }

◆ SLTexColorLUT() [3/3]

SLTexColorLUT::SLTexColorLUT	(	SLAssetManager *	assetMgr,
		SLVAlphaLUTPoint	alphaValues,
		SLVColorLUTPoint	colorValues,
		SLuint	length = `256`
	)

ctor with vector of alpha and color values

Definition at line 64 of file SLTexColorLUT.cpp.

 {
     _min_filter = GL_LINEAR;
     _mag_filter = GL_LINEAR;
     _wrap_s     = GL_CLAMP_TO_EDGE;
     _wrap_t     = GL_CLAMP_TO_EDGE;
     _texType    = TT_diffuse;
     _length     = length;
     _target     = GL_TEXTURE_2D; // OpenGL ES doesn't define 1D textures. We just make a 1 pixel high 2D texture
  
     for (auto color : colorValues)
         _colors.push_back(color);
  
     for (auto alpha : alphaValues)
         _alphas.push_back(alpha);
  
     generateTexture();
  
     // Add pointer to the global resource vectors for deallocation
     if (assetMgr)
         assetMgr->textures().push_back(this);
 }

◆ ~SLTexColorLUT()

SLTexColorLUT::~SLTexColorLUT ( )

virtual

Definition at line 90 of file SLTexColorLUT.cpp.

 {
     _colors.clear();
     _alphas.clear();
 }

Member Function Documentation

◆ allAlphas()

SLVfloat SLTexColorLUT::allAlphas ( )

Returns all alpha values of the transfer function as a float vector.

Definition at line 315 of file SLTexColorLUT.cpp.

 {
     SLVfloat allA;
     allA.resize(_length);
  
     for (SLuint i = 0; i < _length; ++i)
     {
         CVVec4f c4f = _images[0]->getPixeli((SLint)i, 0);
         allA[i]     = c4f[3];
     }
  
     return allA;
 }

◆ allColors()

SLVCol3f SLTexColorLUT::allColors ( )

Returns all alpha values of the transfer function as a float vector.

Definition at line 330 of file SLTexColorLUT.cpp.

 {
     // Finally create color LUT vector by lerping color and alpha values
     SLuint  c      = 0;    // current color segment index
     SLfloat pos    = 0.0f; // overall position between 0-1
     SLfloat posC   = 0.0f; // position in color segment
     SLfloat delta  = 1.0f / (SLfloat)_length;
     SLfloat deltaC = 1.0f / ((_colors[c + 1].pos - _colors[c].pos) / delta);
  
     SLVCol3f lut;
     lut.resize((SLuint)_length);
  
     // Interpolate color values
     for (SLuint i = 0; i < _length; ++i)
     {
         lut[i].r = Utils::lerp(posC, _colors[c].color.r, _colors[c + 1].color.r);
         lut[i].g = Utils::lerp(posC, _colors[c].color.g, _colors[c + 1].color.g);
         lut[i].b = Utils::lerp(posC, _colors[c].color.b, _colors[c + 1].color.b);
  
         pos += delta;
         posC += deltaC;
  
         if (pos > _colors[c + 1].pos && c < _colors.size() - 2)
         {
             c++;
             posC   = 0.0f;
             deltaC = 1.0f / ((_colors[c + 1].pos - _colors[c].pos) / delta);
         }
     }
     return lut;
 }

◆ alphas()

SLVAlphaLUTPoint& SLTexColorLUT::alphas ( )

inline

Definition at line 95 of file SLTexColorLUT.h.

95 { return _alphas; }

◆ colors() [1/2]

SLVColorLUTPoint& SLTexColorLUT::colors ( )

inline

Definition at line 94 of file SLTexColorLUT.h.

94 { return _colors; }

◆ colors() [2/2]

void SLTexColorLUT::colors ( SLColorLUTType lut )

Colors setter function by predefined color LUT.

Definition at line 97 of file SLTexColorLUT.cpp.

 {
     assert(lutType != CLUT_custom && "SLTexColorLUT::colors: Custom LUT now allowed");
  
     _colors.clear();
     _colorLUT = lutType;
  
     switch (lutType)
     {
         case CLUT_BW:
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLACK, 0.0f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::WHITE, 1.0f));
             name("Gradient Texture (LUT): B-W");
             break;
         case CLUT_WB:
             _colors.push_back(SLColorLUTPoint(SLCol3f::WHITE, 0.0f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLACK, 1.0f));
             name("Gradient Texture (LUT): W-B");
             break;
         case CLUT_WYR:
             _colors.push_back(SLColorLUTPoint(SLCol3f::WHITE, 0.0f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::YELLOW, 0.5f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::RED, 1.0f));
             name("Gradient Texture (LUT): W-Y-R");
             break;
         case CLUT_RYGCB:
             _colors.push_back(SLColorLUTPoint(SLCol3f::RED, 0.00f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::YELLOW, 0.25f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::GREEN, 0.50f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::CYAN, 0.75f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLUE, 1.00f));
             name("Gradient Texture (LUT): R-Y-G-C-B");
             break;
         case CLUT_BCGYR:
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLUE, 0.00f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::CYAN, 0.25f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::GREEN, 0.50f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::YELLOW, 0.75f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::RED, 1.00f));
             name("Gradient Texture (LUT): B-C-G-Y-R");
             break;
         case CLUT_RYGCBK:
             _colors.push_back(SLColorLUTPoint(SLCol3f::RED, 0.00f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::YELLOW, 0.20f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::GREEN, 0.40f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::CYAN, 0.60f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLUE, 0.80f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLACK, 1.00f));
             name("Gradient Texture (LUT): R-Y-G-C-B-K");
             break;
         case CLUT_KBCGYR:
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLACK, 0.00f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLUE, 0.20f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::CYAN, 0.40f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::GREEN, 0.60f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::YELLOW, 0.00f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::RED, 1.00f));
             name("Gradient Texture (LUT): K-B-C-G-Y-R");
             break;
         case CLUT_RYGCBM:
             _colors.push_back(SLColorLUTPoint(SLCol3f::RED, 0.00f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::YELLOW, 0.20f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::GREEN, 0.40f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::CYAN, 0.60f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLUE, 0.80f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::MAGENTA, 1.00f));
             name("Gradient Texture (LUT): R-Y-G-C-B-M");
             break;
         case CLUT_MBCGYR:
             _colors.push_back(SLColorLUTPoint(SLCol3f::MAGENTA, 0.00f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::BLUE, 0.20f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::CYAN, 0.40f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::GREEN, 0.60f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::YELLOW, 0.00f));
             _colors.push_back(SLColorLUTPoint(SLCol3f::RED, 1.00f));
             name("Gradient Texture (LUT): M-B-C-G-Y-R");
             break;
         case CLUT_DAYLIGHT:
             // Daylight color ramp with white at noon in the middle
             _colors.push_back(SLColorLUTPoint(SLCol3f(1, 36.0f / 255.0f, 36.0f / 255.0f), 0.00f));
             _colors.push_back(SLColorLUTPoint(SLCol3f(1, 113.0f / 255.0f, 6.0f / 255.0f), 0.05f));
             _colors.push_back(SLColorLUTPoint(SLCol3f(1, 243.0f / 255.0f, 6.0f / 255.0f), 0.10f));
             _colors.push_back(SLColorLUTPoint(SLCol3f(1, 1, 245.0f / 255.0f), 0.20f));
             _colors.push_back(SLColorLUTPoint(SLCol3f(1, 1, 1), 1.00f));
             name("Gradient Texture (LUT): For daylight");
             break;
         default:
             SL_EXIT_MSG("SLTexColorLUT::colors: undefined color LUT.");
             break;
     }
 }

◆ generateTexture()

void SLTexColorLUT::generateTexture ( )

Generates the full 256 value LUT as 1x256 RGBA texture.

Definition at line 190 of file SLTexColorLUT.cpp.

 {
     assert(_length > 1);
     assert(!_colors.empty() &&
            "SLTexColorLUT::generateTexture: Not enough color values.");
  
     // Delete old data in case of regeneration
     deleteData(false);
  
     SLfloat delta = 1.0f / (SLfloat)_length;
  
     // Check and sort alpha values
     if (!_alphas.empty())
     {
         sort(_alphas.begin(),
              _alphas.end(),
              [](SLAlphaLUTPoint a, SLAlphaLUTPoint b)
              { return a.pos < b.pos; });
  
         // Check out of bounds position (0-1)
         if (_alphas.front().pos < 0.0f)
             SL_EXIT_MSG("SLTexColorLUT::generateTexture: Lower alpha pos below 0");
         if (_alphas.back().pos > 1.0f)
             SL_EXIT_MSG("SLTexColorLUT::generateTexture: Upper alpha pos above 1");
         if (_colors.front().pos < 0.0f)
             SL_EXIT_MSG("SLTexColorLUT::generateTexture: Lower color pos below 0");
         if (_colors.back().pos > 1.0f)
             SL_EXIT_MSG("SLTexColorLUT::generateTexture: Upper color pos above 1");
  
         // Add boundary node if they are not at position 0 or 1
         if (_alphas.front().pos > 0.0f)
             _alphas.insert(_alphas.begin(), SLAlphaLUTPoint(_alphas.front().alpha, 0.0f));
         if (_alphas.back().pos < 1.0f)
             _alphas.push_back(SLAlphaLUTPoint(_alphas.back().alpha, 1.0f));
         if (_colors.front().pos > 0.0f)
             _colors.insert(_colors.begin(), SLColorLUTPoint(_colors.front().color, 0.0f));
         if (_colors.back().pos < 1.0f)
             _colors.push_back(SLColorLUTPoint(_colors.back().color, 1.0f));
  
         // Check that the delta between positions is larger than delta
         for (SLuint a = 0; a < _alphas.size() - 1; ++a)
             if ((_alphas[a + 1].pos - _alphas[a].pos) < delta)
                 SL_EXIT_MSG("SLTexColorLUT::generateTexture: Alpha position deltas to small.");
  
         // Clamp alpha values
         for (auto a : _alphas) a.alpha = Utils::clamp(a.alpha, 0.0f, 1.0f);
     }
  
     // Check and sort color values
     sort(_colors.begin(),
          _colors.end(),
          [](SLColorLUTPoint a, SLColorLUTPoint b)
          { return a.pos < b.pos; });
  
     // Check that the delta between positions is larger than delta
     for (SLuint c = 0; c < _colors.size() - 1; ++c)
         if ((_colors[c + 1].pos - _colors[c].pos) < delta)
             SL_EXIT_MSG("SLTexColorLUT::generateTexture: Color position deltas to small.");
  
     // Clamp all colors
     for (auto c : _colors)
         c.color.clampMinMax(0.0f, 1.0f);
  
     // Finally create color LUT vector by lerping color and alpha values
     SLuint  c      = 0;    // current color segment index
     SLfloat pos    = 0.0f; // overall position between 0-1
     SLfloat posC   = 0.0f; // position in color segment
     SLfloat deltaC = 1.0f / ((_colors[c + 1].pos - _colors[c].pos) / delta);
  
     SLVCol4f lut;
     lut.resize((SLuint)_length);
  
     // Interpolate color values
     for (SLuint i = 0; i < _length; ++i)
     {
         lut[i].r = Utils::lerp(posC, _colors[c].color.r, _colors[c + 1].color.r);
         lut[i].g = Utils::lerp(posC, _colors[c].color.g, _colors[c + 1].color.g);
         lut[i].b = Utils::lerp(posC, _colors[c].color.b, _colors[c + 1].color.b);
  
         pos += delta;
         posC += deltaC;
  
         if (pos > _colors[c + 1].pos && c < _colors.size() - 2)
         {
             c++;
             posC   = 0.0f;
             deltaC = 1.0f / ((_colors[c + 1].pos - _colors[c].pos) / delta);
         }
     }
  
     if (!_alphas.empty())
     {
         // Interpolate alpha value
         SLuint  a      = 0;    // current alpha segment index
         SLfloat posA   = 0.0f; // position in alpha segment
         SLfloat deltaA = 1.0f / ((_alphas[a + 1].pos - _alphas[a].pos) / delta);
         pos            = 0.0f;
         for (SLuint i = 0; i < _length; ++i)
         {
             lut[i].a = Utils::lerp(posA, _alphas[a].alpha, _alphas[a + 1].alpha);
             pos += delta;
             posA += deltaA;
  
             if (pos > _alphas[a + 1].pos && a < _alphas.size() - 2)
             {
                 a++;
                 posA   = 0.0f;
                 deltaA = 1.0f / ((_alphas[a + 1].pos - _alphas[a].pos) / delta);
             }
         }
     }
     else
     {
         for (SLuint i = 0; i < _length; ++i)
             lut[i].a = 1.0f;
     }
  
     // Create 1 x length sized image from SLCol4f values
     load(lut);
     _width  = _images[0]->width();
     _height = _images[0]->height();
     _depth  = (SLint)_images.size();
 }

◆ length()

SLuint SLTexColorLUT::length ( )

inline

Definition at line 93 of file SLTexColorLUT.h.

93 { return _length; }

Member Data Documentation

◆ _alphas

SLVAlphaLUTPoint SLTexColorLUT::_alphas

protected

vector of colors in TF

Definition at line 103 of file SLTexColorLUT.h.

◆ _colorLUT

SLColorLUTType SLTexColorLUT::_colorLUT

protected

Length of transfer function (default 256)

Definition at line 101 of file SLTexColorLUT.h.

◆ _colors

SLVColorLUTPoint SLTexColorLUT::_colors

protected

Color LUT identifier.

Definition at line 102 of file SLTexColorLUT.h.

◆ _length

SLuint SLTexColorLUT::_length

protected

Definition at line 100 of file SLTexColorLUT.h.

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

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SLTexColorLUT() [1/3]

◆ SLTexColorLUT() [2/3]

◆ SLTexColorLUT() [3/3]

◆ ~SLTexColorLUT()

Member Function Documentation

◆ allAlphas()

◆ allColors()

◆ alphas()

◆ colors() [1/2]

◆ colors() [2/2]

◆ generateTexture()

◆ length()

Member Data Documentation

◆ _alphas

◆ _colorLUT

◆ _colors

◆ _length