Color palettes

CHANGELOG

@@ -9,6 +9,20 @@
                              https://glvis.org
 
 
+Version 4.y.z released on
+======================================
+
+- Implemented a more flexible color palette system, enabling specification
+  at both compile and run time. Run time palettes are specified with a file
+  and the command line argument '-p <palette_filename>'. Palettes can now
+  also be specified with explicit alpha channels, (see
+  'share/palettes-variable-opacity.txt').
+
+- Added 28 new color-vision deficiency friendly and perceptually-uniform
+  color palettes: 'share/palettes-crameri.txt'
+
+- Fixed a bug where discrete textures would not repeat.
+
 Version 4.3.2 released on Sep 27, 2024
 ======================================
 

NOTICE

@@ -26,3 +26,4 @@ their own respective licenses which can be found in their code and attached
 license files. These software products and their licenses are as follows:
 
 * GL2PS (linalg/gl2ps.{h,c}) -- Custom 1-clause license
+* Additional color palettes (share/palettes-crameri.txt) -- MIT license

glvis.cpp

@@ -1325,6 +1325,7 @@ int main (int argc, char *argv[])
    bool        save_stream   = false;
    const char *stream_file   = string_none;
    const char *script_file   = string_none;
+   const char *palette_file  = string_none;
    const char *font_name     = string_default;
    int         portnum       = 19916;
    int         multisample   = GetMultisample();
@@ -1358,6 +1359,8 @@ int main (int argc, char *argv[])
                   "Number of digits used for processor ranks in file names.");
    args.AddOption(&script_file, "-run", "--run-script",
                   "Run a GLVis script file.");
+   args.AddOption(&palette_file, "-p", "--palettes",
+                  "Palette file.");
    args.AddOption(&arg_keys, "-k", "--keys",
                   "Execute key shortcut commands in the GLVis window.");
    args.AddOption(&stream_state.fix_elem_orient, "-fo", "--fix-orientations",
@@ -1487,6 +1490,12 @@ int main (int argc, char *argv[])
    }
    SetUseHiDPI(enable_hidpi);
 
+   // Load in palette file, if specified
+   if (palette_file != string_none)
+   {
+      BasePalettes.load(palette_file);
+   }
+
    GLVisGeometryRefiner.SetType(geom_ref_type);
 
    string data_type;

lib/CMakeLists.txt

@@ -20,6 +20,7 @@ list(APPEND SOURCES
   material.cpp
   openglvis.cpp
   palettes.cpp
+  palettes_base.cpp
   sdl.cpp
   sdl_helper.cpp
   sdl_main.cpp
@@ -45,6 +46,7 @@ list(APPEND HEADERS
   material.hpp
   openglvis.hpp
   palettes.hpp
+  palettes_base.hpp
   sdl.hpp
   sdl_helper.hpp
   sdl_main.hpp

lib/openglvis.cpp

@@ -479,7 +479,7 @@ VisualizationScene::AddPaletteMaterial(glTF_Builder &bld)
          /* wrapT: */ glTF_Builder::wrap_type::CLAMP_TO_EDGE);
    // create palette image
    const int palette_size = palette.GetNumColors();
-   vector<array<float,4>> palette_data(palette_size);
+   vector<array<float,4>> palette_data = palette.GetPalette()->data();
 #if 0
    glGetTextureImage(
       palette.GetColorTexture(), 0,
@@ -491,16 +491,6 @@ VisualizationScene::AddPaletteMaterial(glTF_Builder &bld)
    glGetTexImage(GL_TEXTURE_2D, 0,
                  gl3::GLDevice::useLegacyTextureFmts() ? GL_RGBA : GL_RGBA32F,
                  GL_FLOAT, palette_data.data());
-#else
-   const double *palette_data_raw = palette.GetData();
-   for (int i = 0; i < palette_size; ++i)
-   {
-      for (int j = 0; j < 3; ++j)
-      {
-         palette_data[i][j] = (float) palette_data_raw[j + 3*i];
-      }
-      palette_data[i][3] = 1.0f;
-   }
 #endif
    auto palette_img =
       bld.addImage(