colormap-shaders

A collection of shaders to draw color map like this:

.

usage

Each *.frag shader sources provides a colormap function, which takes an float argument x (x should be: 0.0 <= x <= 1.0). The colormap function returns a vec4 value which represents an RGBA color.

vec4 colormap(float x);

void main() {
    gl_FragColor = colormap(gl_TexCoord[0].x);
}

/* include "shaders/rainbow.frag" here, for example. */

special case

gnuplot.frag

This shader emulates gnuplot's rgbformulae, and the signature of colormap is:

vec4 colormap(float x, int red_type, int green_type, int blue_type);

It takes additional 3 arguments, with same meanings to rgbformulae's 3 arguments respectively.

usage from c++

#include <colormap/colormap.h>
#include <iostream>

int main()
{
    using namespace colormap;

    // Print RGB table of MATLAB::Jet colormap.
    MATLAB::Jet jet;
    std::cout << "category: " << jet.getCategory() << std::endl;
    std::cout << "title:    " << jet.getTitle() << std::endl;
    int const size = 256;
    for (int i = 0; i < size; ++i) {
        float const x = i / (float)size;
        Color c = jet.getColor(x);
        std::cout << x << "\t" << c.r << "\t" << c.g << "\t" << c.b << std::endl;
    }

    // Dump category and title of all colormaps.
    for (std::shared_ptr<Colormap const> const& c : ColormapList::getAll()) {
        std::cout << c->getCategory() << " : " << c->getTitle() << std::endl;
    }
    return 0;
}

samples

MATLAB

• http://www.mathworks.com/products/matlab/

name	sample
MATLAB_autumn
MATLAB_bone
MATLAB_cool
MATLAB_copper
MATLAB_hot
MATLAB_hsv
MATLAB_jet
MATLAB_parula
MATLAB_pink
MATLAB_spring
MATLAB_summer
MATLAB_winter

gnuplot

• http://www.gnuplot.info/

name	sample
rgbformulae(7, 5, 15)
rgbformulae(3, 11, 6)
rgbformulae(23, 28, 3)
rgbformulae(21, 22, 23)
rgbformulae(30, 31, 32)
rgbformulae(33, 13, 10)
rgbformulae(34, 35, 36)

IDL

• http://www.exelisvis.com/ProductsServices/IDL.aspx

name	sample
IDL_Black-White_Linear
IDL_Blue-White_Linear
IDL_Green-Red-Blue-White
IDL_Red_Temperature
IDL_Blue-Green-Red-Yellow
IDL_Standard_Gamma-II
IDL_Prism
IDL_Red-Purple
IDL_Green-White_Linear
IDL_Green-White_Exponential
IDL_Green-Pink
IDL_Blue-Red
IDL_16_Level
IDL_Rainbow
IDL_Steps
IDL_Stern_Special
IDL_Haze
IDL_Blue-Pastel-Red
IDL_Pastels
IDL_Hue_Sat_Lightness_1
IDL_Hue_Sat_Lightness_2
IDL_Hue_Sat_Value_1
IDL_Hue_Sat_Value_2
IDL_Purple-Red+Stripes
IDL_Beach
IDL_Mac_Style
IDL_Eos_A
IDL_Eos_B
IDL_Hardcandy
IDL_Nature
IDL_Ocean
IDL_Peppermint
IDL_Plasma
IDL_Blue-Red_2
IDL_Rainbow_2
IDL_Blue_Waves
IDL_Volcano
IDL_Waves
IDL_Rainbow_18
IDL_Rainbow+White
IDL_Rainbow+Black
IDL_CB-Accent
IDL_CB-Dark2
IDL_CB-Paired
IDL_CB-Pastel1
IDL_CB-Pastel2
IDL_CB-Set1
IDL_CB-Set2
IDL_CB-Set3
IDL_CB-Blues
IDL_CB-BuGn
IDL_CB-BuPu
IDL_CB-GnBu
IDL_CB-Greens
IDL_CB-Greys
IDL_CB-Oranges
IDL_CB-OrRd
IDL_CB-PuBu
IDL_CB-PuBuGn
IDL_CB-PuRdn
IDL_CB-Purples
IDL_CB-RdPu
IDL_CB-Reds
IDL_CB-YIGn
IDL_CB-YIGnBu
IDL_CB-YIOrBr
IDL_CB-BrBG
IDL_CB-PiYG
IDL_CB-PRGn
IDL_CB-PuOr
IDL_CB-RdBu
IDL_CB-RdGy
IDL_CB-RdYiBu
IDL_CB-RdYiGn
IDL_CB-Spectral

transform

• http://web.archive.org/web/20000520021207/http://www.fortner.com/docs/product_transform.html

name	sample
transform_rainbow
transform_apricot
transform_carnation
transform_ether
transform_grayscale_banded
transform_hot_metal
transform_lava_waves
transform_malachite
transform_seismic
transform_space
transform_morning_glory
transform_peanut_butter_and_jerry
transform_purple_haze
transform_rose
transform_saturn
transform_supernova

transform

name	sample
kbinani_altitude

license

The MIT License. See 'LICENSE' file for detail.