Method EstimateTriangleCount

include/imgui/imgui_draw.cpp:1858–1858

struct ImTriangulator
{
    static int EstimateTriangleCount(int points_count)      { return (points_count < 3) ? 0 : points_count - 2; }
    static int EstimateScratchBufferSize(int points_count)  { return sizeof(ImTriangulatorNode) * points_count + sizeof(ImTriangulatorNode*) * points_count * 2; }

    void    Init(const ImVec2* points, int points_count, void* scratch_buffer);