Commit 07217a99 authored by Paul Asmuth's avatar Paul Asmuth
Browse files

add the 'categorical' scale type and axis layout

parent 7cc4aa38

core/format.cc

+6 −0
Original line number Diff line number Diff line
@@ -118,6 +118,12 @@ Formatter format_string() { 
  };

}



Formatter format_noop() {

  return [] (size_t idx, const std::string& v) -> std::string {

    return {};

  };

}



ReturnCode format_configure_string(

    const Expr* expr,

    Formatter* formatter) {

core/format.h

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ Formatter format_decimal_scientific(size_t precision); 
Formatter format_datetime(const std::string& fmt);

Formatter format_string();

Formatter format_custom(const std::vector<std::string>& values);

Formatter format_noop();



ReturnCode format_configure(

    const Expr* expr,

core/scale.cc

+47 −3
Original line number Diff line number Diff line
@@ -195,12 +195,24 @@ ReturnCode scale_configure_kind( 
      continue;

    }



    if (expr_is_value(expr, "categorical")) {

      domain->kind = ScaleKind::CATEGORICAL;



      expr = expr_next(expr);

      if (auto rc = expr_to_strings(expr, &domain->categories); !rc) {

        return rc;

      }



      continue;

    }



    return err_invalid_value(expr_inspect(expr), {

      "linear",

      "log",

      "logarithmic",

      "invert",

      "inverted"

      "inverted",

      "categorical"

    });

  }
@@ -209,12 +221,14 @@ ReturnCode scale_configure_kind( 


ReturnCode scale_layout_linear(

    const ScaleConfig& domain,

    const Formatter& label_format,

    ScaleLayout* layout,

    double step,

    std::optional<double> o_begin,

    std::optional<double> o_end) {

  layout->ticks.clear();

  layout->labels.clear();

  layout->label_text.clear();



  auto begin = std::max(o_begin.value_or(scale_min(domain)), scale_min(domain));

  auto end = std::min(o_end.value_or(scale_max(domain)), scale_max(domain));
@@ -223,11 +237,12 @@ ReturnCode scale_layout_linear( 
    return {ERROR, "too many ticks"};

  }



  size_t label_idx = 0;

  size_t idx = 0;

  for (auto v = begin; v <= end; v += step) {

    auto vp = scale_translate(domain, v);

    layout->ticks.emplace_back(vp);

    layout->labels.emplace_back(vp);

    layout->label_text.emplace_back(label_format(idx++, std::to_string(v))); // FIXME

  }



  return OK;
@@ -235,15 +250,19 @@ ReturnCode scale_layout_linear( 


ReturnCode scale_layout_subdivide(

    const ScaleConfig& domain,

    const Formatter& label_format,

    ScaleLayout* layout,

    uint32_t divisions) {

  layout->ticks.clear();

  layout->labels.clear();

  layout->label_text.clear();



  for (size_t i = 0; i <= divisions; ++i) {

    auto o = (1.0f / divisions) * i;

    layout->ticks.emplace_back(o);

    layout->labels.emplace_back(o);

    layout->label_text.emplace_back(

        label_format(i, std::to_string(scale_untranslate(domain, o)))); // FIXME

  }



  return OK;
@@ -251,11 +270,13 @@ ReturnCode scale_layout_subdivide( 


ReturnCode scale_layout_discrete(

    const ScaleConfig& domain,

    const Formatter& label_format,

    ScaleLayout* layout) {

  uint32_t step = 1;

  uint32_t range = scale_max(domain) - scale_min(domain);



  layout->labels.clear();

  layout->label_text.clear();

  layout->ticks.clear();



  for (size_t i = 0; i <= range; i += step) {
@@ -267,6 +288,8 @@ ReturnCode scale_layout_discrete( 


    if (o1 >= 0 && o2 <= 1) {

      layout->labels.emplace_back(o);

      layout->label_text.emplace_back(

          label_format(i - 1, std::to_string(scale_untranslate(domain, o)))); // FIXME

    }



    if (o1 >= 0 && o1 <= 1) {
@@ -281,6 +304,25 @@ ReturnCode scale_layout_discrete( 
  return OK;

}



ReturnCode scale_layout_categorical(

    const ScaleConfig& domain,

    const Formatter& label_format,

    ScaleLayout* layout) {

  layout->labels.clear();

  layout->label_text.clear();

  layout->ticks.clear();



  auto n = domain.categories.size();

  for (size_t i = 0; i < n; ++i) {

    auto o =  double(i + 1) / (n + 1);

    layout->labels.emplace_back(o);

    layout->label_text.emplace_back(label_format(i, domain.categories[i]));

    layout->ticks.push_back(o);

  }



  return OK;

}



ReturnCode scale_configure_layout_linear(

    const Expr* expr,

    ScaleLayoutFn* layout) {
@@ -318,6 +360,7 @@ ReturnCode scale_configure_layout_linear( 
      &scale_layout_linear,

      _1,

      _2,

      _3,

      step,

      begin,

      end);
@@ -350,6 +393,7 @@ ReturnCode scale_configure_layout_subdivide( 
      &scale_layout_subdivide,

      _1,

      _2,

      _3,

      subdivisions);



  return OK;
@@ -376,7 +420,7 @@ ReturnCode scale_configure_layout( 
  }



  if (expr_is_value(expr, "discrete")) {

    *layout = bind(&scale_layout_discrete, _1, _2);

    *layout = bind(&scale_layout_discrete, _1, _2, _3);

    return OK;

  }

core/scale.h

+17 −2
Original line number Diff line number Diff line
@@ -22,11 +22,12 @@ 
#include "return_code.h"

#include "sexpr.h"

#include "color_scheme.h"

#include "format.h"



namespace fviz {



enum class ScaleKind {

  LINEAR, LOGARITHMIC

  LINEAR, LOGARITHMIC, CATEGORICAL

};



struct ScaleLimitHints {
@@ -43,14 +44,20 @@ struct ScaleConfig { 
  bool inverted;

  double padding;

  std::shared_ptr<ScaleLimitHints> limit_hints;

  std::vector<std::string> categories;

};



struct ScaleLayout {

  std::vector<double> ticks;

  std::vector<double> labels;

  std::vector<std::string> label_text;

};



using ScaleLayoutFn = std::function<void (const ScaleConfig&, ScaleLayout*)>;

using ScaleLayoutFn = std::function<

    void (

        const ScaleConfig&,

        const Formatter&,

        ScaleLayout*)>;



void scale_fit(double value, ScaleConfig* domain);
@@ -77,6 +84,7 @@ ReturnCode scale_configure_kind( 


ReturnCode scale_layout_linear(

    const ScaleConfig& domain,

    const Formatter& label_format,

    ScaleLayout* layout,

    double step,

    std::optional<double> begin,
@@ -84,11 +92,18 @@ ReturnCode scale_layout_linear( 


ReturnCode scale_layout_subdivide(

    const ScaleConfig& domain,

    const Formatter& label_format,

    ScaleLayout* layout,

    uint32_t divisions);



ReturnCode scale_layout_discrete(

    const ScaleConfig& domain,

    const Formatter& label_format,

    ScaleLayout* layout);



ReturnCode scale_layout_categorical(

    const ScaleConfig& domain,

    const Formatter& label_format,

    ScaleLayout* layout);



ReturnCode scale_configure_layout(

elements/chart/axis.cc

+22 −17
Original line number Diff line number Diff line
@@ -131,15 +131,6 @@ void axis_convert_units(AxisDefinition* config, const Layer& layer) { 
      &config->tick_length);

}



std::string axis_get_label(

    const AxisDefinition& axis,

    size_t idx,

    double offset) {

  const auto& domain = axis.scale;

  auto value = scale_untranslate(domain, offset);

  return axis.label_formatter(idx, std::to_string(value));

}



ReturnCode axis_layout_labels(

    const AxisDefinition& axis,

    const AxisPosition& axis_position,
@@ -147,13 +138,13 @@ ReturnCode axis_layout_labels( 
    double* margin) {

  /* compute scale layout */

  ScaleLayout slayout;

  axis.scale_layout(axis.scale, &slayout);

  axis.scale_layout(axis.scale, axis.label_formatter, &slayout);



  /* compute label margin */

  double label_margin = 0;

  for (size_t i = 0; i < slayout.labels.size(); ++i) {

    auto tick = slayout.labels[i];

    auto label_text = axis_get_label(axis, i, tick);

    auto label_text = slayout.label_text[i];



    TextStyle style;

    style.font = axis.label_font;
@@ -348,7 +339,7 @@ static ReturnCode axis_draw_vertical( 
    Layer* target) {

  /* compute layout */

  ScaleLayout slayout;

  axis_config.scale_layout(axis_config.scale, &slayout);

  axis_config.scale_layout(axis_config.scale, axis_config.label_formatter, &slayout);



  /* draw axis line */

  strokeLine(target, {x, y0}, {x, y1}, axis_config.border_style);
@@ -409,7 +400,7 @@ static ReturnCode axis_draw_vertical( 


  for (size_t i = 0; i < slayout.labels.size(); ++i) {

    auto tick = slayout.labels[i];

    auto label_text = axis_get_label(axis_config, i, tick);

    auto label_text = slayout.label_text[i];



    Point p;

    p.x = x + label_padding * label_position;
@@ -529,7 +520,10 @@ static ReturnCode axis_draw_horizontal( 
    Layer* target) {

  /* compute layout */

  ScaleLayout slayout;

  axis_config.scale_layout(axis_config.scale, &slayout);

  axis_config.scale_layout(

      axis_config.scale,

      axis_config.label_formatter,

      &slayout);



  /* draw axis line */

  strokeLine(target, {x0, y}, {x1, y}, axis_config.border_style);
@@ -590,7 +584,7 @@ static ReturnCode axis_draw_horizontal( 


  for (size_t i = 0; i < slayout.labels.size(); ++i) {

    auto tick = slayout.labels[i];

    auto label_text = axis_get_label(axis_config, i, tick);

    auto label_text = slayout.label_text[i];



    Point p;

    p.x = x0 + (x1 - x0) * tick;
@@ -760,7 +754,6 @@ ReturnCode build(const Environment& env, const Expr* expr, ElementRef* elem) { 
  config->title_font = env.font;

  config->title_font_size = env.font_size;

  config->title_color = env.text_color;

  config->scale_layout = bind(&scale_layout_subdivide, _1, _2, 10);

  config->border_style.line_width = from_pt(1);

  config->border_style.color = env.border_color;
@@ -838,9 +831,21 @@ ReturnCode build(const Environment& env, const Expr* expr, ElementRef* elem) { 
    }

  }



  if (!config->scale_layout) {

    if (config->scale.kind == ScaleKind::CATEGORICAL) {

      config->scale_layout = bind(&scale_layout_categorical, _1, _2, _3);

    } else {

      config->scale_layout = bind(&scale_layout_subdivide, _1, _2, _3, 10);

    }

  }



  if (!config->label_formatter) {

    if (config->scale.kind == ScaleKind::CATEGORICAL) {

      config->label_formatter = format_string();

    } else {

      config->label_formatter = format_decimal_fixed(1);

    }

  }



  switch (config->tick_position) {

    case AxisLabelPosition::OUTSIDE:

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