// Filename: geomEnums.h
// Created by:  drose (14Apr05)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001 - 2004, Disney Enterprises, Inc.  All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license.  You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://etc.cmu.edu/panda3d/docs/license/ .
//
// To contact the maintainers of this program write to
// panda3d-general@lists.sourceforge.net .
//
////////////////////////////////////////////////////////////////////

#ifndef GEOMENUMS_H
#define GEOMENUMS_H

#include "pandabase.h"

////////////////////////////////////////////////////////////////////
//       Class : GeomEnums
// Description : This class exists just to provide scoping for the
//               various enumerated types used by Geom,
//               GeomVertexData, GeomVertexArrayData, GeomPrimitive,
//               and other related classes.
////////////////////////////////////////////////////////////////////
class EXPCL_PANDA GeomEnums {
PUBLISHED:

  // The usage hint describes to the rendering backend how often the
  // data in question will be modified and/or rendered.  It allows the
  // backend to make appropriate choices about what part of memory the
  // data should be stored in.

  // The hint is provided as a performance optimization only, and does
  // not constrain actual usage; although it may be an important
  // optimization.

  enum UsageHint {
    // The following are intentionally ordered from most dynamic to
    // most static.  In general, if usage_a < usage_b, then usage_a is
    // more dynamic than usage_b.

    // UH_client: don't attempt to upload the data; always keep it on
    // the client.
    UH_client,

    // UH_stream: the data will be created once, used to render a few
    // times, and then discarded.  This should be used for short-lived
    // temporary objects.
    UH_stream,

    // UH_dynamic: the data will be repeatedly modified and
    // re-rendered.  This is for data that will be modified at
    // runtime, such as animated or soft-skinned vertices.
    UH_dynamic,

    // UH_static: the data will be created once, and used to render
    // many times, without modification.  This is the most common
    // case, since typically vertex data is not directly animated
    // (this is not related to scene graph animation, e.g. from
    // adjusting transforms on a node).
    UH_static,

    // UH_unspecified: the usage is unspecified.  This is intended as
    // a "don't care" option for abstract objects, it should not be
    // applied to any actual geometry to be rendered.  You take your
    // chances if a geom actually gets into the scene graph with this
    // set.
    UH_unspecified,
  };

  // This type specifies a number of bits that are used to represent
  // the rendering requirements of a particular Geom, as well as the
  // rendering capabilities of the GSG.  The difference between the
  // two indicates whether the Geom needs to be munged for the GSG.
  enum GeomRendering {
    // If there are indexed points.
    GR_indexed_point        = 0x00001,

    // If there is indexed geometry of any other type.
    GR_indexed_other        = 0x10000,

    // The union of all of the indexed attributes.
    GR_indexed_bits         = 0x10001,

    // If there are any points at all.
    GR_point                = 0x00002,

    // If the points are all the same size, other than 1 pixel.
    GR_point_uniform_size   = 0x00004,

    // If the points have a per-vertex size designation.
    GR_per_point_size       = 0x00008,

    // If the points' size is specified in camera units rather than
    // screen pixels.
    GR_point_perspective    = 0x00010,

    // If the points have a non-square aspect ratio.
    GR_point_aspect_ratio   = 0x00020,

    // If the points are under a scale transform, uniform or non-uniform.
    GR_point_scale          = 0x00040,

    // If the points are rotated off the orthonormal axis.
    GR_point_rotate         = 0x00080,

    // If the points require texture coordinates interpolated across
    // their face, to render textures as sprites.
    GR_point_sprite         = 0x00100,

    // If there is a texture matrix applied to the sprite's generated
    // texture coordinates.
    GR_point_sprite_tex_matrix = 0x00200,

    // The union of all the above point attributes, except GR_indexed_point.
    GR_point_bits           = 0x003fe,

    // If there are any of these composite types.
    GR_triangle_strip       = 0x00400,
    GR_triangle_fan         = 0x00800,
    GR_line_strip           = 0x01000,

    // The union of all of the above composite types.
    GR_composite_bits       = 0x01c00,

    // If the shade model requires a particular vertex for flat shading.
    GR_flat_first_vertex    = 0x02000,
    GR_flat_last_vertex     = 0x04000,

    // The union of the above shade model types.
    GR_shade_model_bits     = 0x06000,

    // If there is a TexGenAttrib in effect with M_light_vector
    // enabled, meaning we need to generate the tangent space light
    // vector as the texture coordinates.
    GR_texcoord_light_vector = 0x08000,
  };

  // The shade model specifies whether the per-vertex colors and
  // normals indexed by a given primitive truly represent per-vertex
  // colors and normals, or whether they actually represent
  // per-triangle flat-shaded colors and normals.
  enum ShadeModel {
    // SM_uniform: all vertices across all faces have the same colors
    // and normals.  It doesn't really matter which ShadeModelAttrib
    // mode is used to render this primitive.
    SM_uniform, 

    // SM_smooth: vertices within a single face have different
    // colors/normals that should be smoothed across the face.  This
    // primitive should be rendered with SmoothModelAttrib::M_smooth.
    SM_smooth,  

    // SM_flat_(first,last)_vertex: each face within the primitive
    // might have a different color/normal than the other faces, but
    // across a particular face there is only one color/normal.  Each
    // face's color/normal is taken from the (first, last) vertex of
    // the face.  This primitive should be rendered with
    // SmoothModelAttrib::M_flat.
    SM_flat_first_vertex,
    SM_flat_last_vertex,
  };

  // The primitive type represents the core primitive type of a
  // particular GeomPrimitive.  It's used for determining what kind of
  // antialiasing should be enabled.
  enum PrimitiveType {
    PT_none,
    PT_polygons,
    PT_lines,
    PT_points
  };

  // The numeric type determines what physical representation is used
  // to encode a numeric value within the vertex data.
  enum NumericType {
    NT_uint8,        // An integer 0..255
    NT_uint16,       // An integer 0..65535
    NT_uint32,       // An integer 0..4294967296
    NT_packed_dcba,  // DirectX style, four byte values packed in a uint32
    NT_packed_dabc,  // DirectX packed color order (ARGB)
    NT_float32,      // A floating-point number
  };

  // The contents determine the semantic meaning of a numeric value
  // within the vertex data.  This is also used to determine what
  // automatic transforms might be applied to the various columns.
  enum Contents {
    C_other,        // Arbitrary meaning, leave it alone
    C_point,        // A point in 3-space or 4-space
    C_clip_point,   // A point pre-transformed into clip coordinates
    C_vector,       // A surface normal, tangent, or binormal
    C_texcoord,     // A texture coordinate
    C_color,        // 3- or 4-component color, ordered R, G, B, [A]
    C_index,        // An index value into some other table
    C_morph_delta,  // A delta from some base value, defining a blend shape
  };

  // The type of animation data that is represented by a particular
  // GeomVertexFormat.
  enum AnimationType {
    AT_none,     // No vertex animation.
    AT_panda,    // Vertex animation calculated on the CPU by Panda.
    AT_hardware, // Hardware-accelerated animation on the graphics card.
  };
};

EXPCL_PANDA ostream &operator << (ostream &out, GeomEnums::NumericType numeric_type);
EXPCL_PANDA ostream &operator << (ostream &out, GeomEnums::Contents contents);

#endif

