egutierrez
643d3a2abf
treemap_layout devuelve TreemapRect{min, max, item} con coords absolutas
dentro de la region. La suma de areas == area total (verificado via test
standalone, ratio=1.000000). El render usa AddRectFilled + AddText cuando
labels y valores caben dentro de la cell.
Limitaciones MVP: jerarquia plana (no recursivo), sin interaccion.
67 lines
2.3 KiB
Markdown
67 lines
2.3 KiB
Markdown
---
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name: treemap
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kind: component
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lang: cpp
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domain: viz
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version: "1.0.0"
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purity: pure
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signature: "void treemap(const char* id, const std::vector<TreemapItem>& items, ImVec2 size)"
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description: "Squarified treemap (Bruls, Huijbrechts, van Wijk) para jerarquias planas con valores. Layout puro separado del render."
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tags: [imgui, drawlist, chart, visualization, treemap, hierarchy, squarified]
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uses_functions: []
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uses_types: []
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returns: []
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returns_optional: false
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error_type: ""
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imports: [imgui]
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tested: false
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tests: []
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test_file_path: ""
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file_path: "cpp/functions/viz/treemap.cpp"
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framework: imgui
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params:
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- name: id
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desc: "Identificador unico para PushID (evita colisiones entre treemaps)"
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- name: items
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desc: "Vector de TreemapItem {label, value, color}. Items con value <= 0 se ignoran"
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- name: size
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desc: "Tamano del rect del treemap. x <= 0 usa el ancho disponible"
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output: "Renderiza el treemap en el frame ImGui actual usando AddRectFilled + AddText sobre el WindowDrawList"
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---
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# treemap
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Treemap squarified: dado un vector de items con valor numerico, divide el rect dado en cells cuya area es proporcional al valor del item. El algoritmo de Bruls et al. minimiza el aspect ratio (cells lo mas cuadradas posibles).
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## API
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```cpp
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struct TreemapItem { std::string label; float value; ImU32 color; };
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struct TreemapRect { ImVec2 min, max; const TreemapItem* item; };
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std::vector<TreemapRect> treemap_layout(const std::vector<TreemapItem>&, ImVec2 region); // pure
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void treemap(const char* id, const std::vector<TreemapItem>&, ImVec2 size = {-1, 300});
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```
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`treemap_layout` es pura — devuelve rects en coords [0..region]. `treemap` invoca el layout y renderiza con `AddRectFilled` + label + valor cuando caben.
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## Conservacion del area
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La suma de areas de los rects es igual al area de la region (modulo errores de redondeo). Util para tests.
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## Limitaciones MVP
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- Solo jerarquia plana (no recursivo). Para jerarquias anidadas, llamar `treemap_layout` recursivamente sobre cada cell.
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- Sin interaccion (click, zoom).
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## Ejemplo
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```cpp
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std::vector<TreemapItem> items = {
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{"vivienda", 950, IM_COL32(180,120,200,255)},
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{"comida", 320, IM_COL32(120,180,200,255)},
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{"transporte", 180, IM_COL32(200,180,120,255)},
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};
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treemap("##gastos", items, ImVec2(-1, 300));
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```
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