CAST II Game Engine

Units

Class Hierarchy

Classes, Interfaces and Objects

Functions and Procedures

Identifiers

Class TTesselator

Unit

C2Visual

Declaration

type TTesselator = class(TReferencedItem)

Description

Performs triangulation of visible items

Visible items are different - GUI elements, 3D meshes, procedural models, etc. [b]TTesselator[/b] contains methods to convert an item to its triangulated representation.

Hierarchy

TReferencedItem

Fields

	Name	Description
	`CommandBlock`	Command block ID For render speedup. E.g. OpenGL display list ID.
	`CommandBlockValid`	Determines if command block is a currently valid ID
	`CompositeMember`
	`CompositeOffset`
	`ElementOffs`
	`FVertexFormat`
	`FVertexSize`
	`IndexingVertices`	Number of vertices referenced by indices
	`IndicesRes`
	`LastTotalIndices`	Index: Integer;
	`LastTotalVertices`	Index: Integer;
	`ManualRender`
	`PrimitiveType`	Primitive type
	`StripOffset`	Offset in vertex buffer for each strip
	`TesselationStatus`	Current tesselation status
	`TotalIndices`	Total indices in all strips
	`TotalPrimitives`	Total primitives in each strip
	`TotalStrips`	Total strips
	`TotalVertices`	Total vetices in all strips
	`VerticesRes`

Methods

Overview

	`constructor Create; virtual;`
	`procedure AddProperties(const Result: Props.TProperties); virtual;`
	`procedure BeginLighting; virtual; abstract;`
	`function CalculateLighting(const ALight: TLight; const ALightToItem: TMatrix4s): Boolean; virtual; abstract;`
	`procedure DoManualRender(Item: TItem); virtual; abstract;`
	`function GetBoundingBox: TBoundingBox; virtual;`
	`function GetIndex(AOffset: Integer; AIBuf: Pointer): Integer;`
	`function GetMaxAmount(Buffer: TTesselationBuffer): Integer;`
	`function GetMaxIndices: Integer; virtual;`
	`function GetMaxVertices: Integer; virtual;`
	`function GetUpdatedElements(Buffer: TTesselationBuffer; const Params: TTesselationParameters): Integer; virtual;`
	`function GetVertexDataC(AIndex: Integer; AVBuf: Pointer): TVector3s;`
	`procedure Init; virtual;`
	`procedure InitVertexFormat(Format: Integer); virtual;`
	`procedure Invalidate(ABuffer: TTesselationBufferSet; EntireBuffer: Boolean);`
	`procedure InvalidateBoundingBox;`
	`procedure SetIndex(AValue, AOffset: Integer; AIBuf: Pointer);`
	`function SetIndices(IBPTR: Pointer): Integer; virtual;`
	`procedure SetProperties(Properties: Props.TProperties); virtual;`
	`procedure SetVertexData2UV(u, v: Single; Index: Integer; VBuf: Pointer);`
	`procedure SetVertexDataC(x, y, z: Single; Index: Integer; VBuf: Pointer); overload;`
	`procedure SetVertexDataC(const Vec: TVector3s; Index: Integer; VBuf: Pointer); overload;`
	`procedure SetVertexDataCRHW(x, y, z, RHW: Single; Index: Integer; VBuf: Pointer);`
	`procedure SetVertexDataD(Color: TColor; Index: Integer; VBuf: Pointer);`
	`procedure SetVertexDataN(nx, ny, nz: Single; Index: Integer; VBuf: Pointer); overload;`
	`procedure SetVertexDataN(const Vec: TVector3s; Index: Integer; VBuf: Pointer); overload;`
	`procedure SetVertexDataS(Color: TColor; Index: Integer; VBuf: Pointer);`
	`procedure SetVertexDataUV(u, v: Single; Index: Integer; VBuf: Pointer);`
	`procedure SetVertexDataUV3(u, v, w: Single; Index: Integer; VBuf: Pointer);`
	`procedure SetVertexDataW(w: Single; Index: Integer; VBuf: Pointer);`
	`function Tesselate(const Params: TTesselationParameters; VBPTR: Pointer): Integer; virtual;`
	`function Validate: Boolean; virtual;`

Description

constructor Create; virtual;

{$IFDEF DEBUGMODE} LastMaxVertices: Integer; {$ENDIF} // Used only for debugging

procedure AddProperties(const Result: Props.TProperties); virtual;

Can be overridden to add some properties in addition to ones of a visible item which uses the tesselator. Called from AddProperties of TVisible. Object links can not be used or resolved here.

procedure BeginLighting; virtual; abstract;

Manual lighting begin

function CalculateLighting(const ALight: TLight; const ALightToItem: TMatrix4s): Boolean; virtual; abstract;

Perform manual lighting

procedure DoManualRender(Item: TItem); virtual; abstract;

function GetBoundingBox: TBoundingBox; virtual;

function GetIndex(AOffset: Integer; AIBuf: Pointer): Integer;

Returns an index from index buffer

function GetMaxAmount(Buffer: TTesselationBuffer): Integer;

Returns maximum amount of elements in the specified buffer type

function GetMaxIndices: Integer; virtual;

Should return a maximum possible amount of indices for the tesselator object to reserve place in buffers.
For rarely updated tesselators which still can have a variable number of indices it's reasonable to use a static tesselator with GetMaxVertices the maximum amount of indices. The return value of this function can vary but its change should be indicated with the tsMaxSizeChanged teselation status and will cause discarding of a buffer which may cause performance penalty at lest for static buffers.

function GetMaxVertices: Integer; virtual;

Should return a maximum possible amount of vertices for the tesselator object to reserve place in buffers.
For rarely updated tesselators which still can have a variable number of vertices it's reasonable to use a static tesselator with GetMaxVertices the maximum amount of vertices. The return value of this function can vary but its change should be indicated with the tsMaxSizeChanged teselation status and will cause discarding of a buffer which may cause performance penalty at lest for static buffers.

function GetUpdatedElements(Buffer: TTesselationBuffer; const Params: TTesselationParameters): Integer; virtual;

Returns number of elements in the specified buffer type which needs to be updated in an API buffers. This function called by engine static buffers management routine to determine if lock/fill/unlock procedure needed for each tesselator. If the function returns 0 no update needed.

function GetVertexDataC(AIndex: Integer; AVBuf: Pointer): TVector3s;

Get a coordinate set from vertex buffer. [b]AIndex[/b] - element index, [b]AVBuf[/b] - pointer to vertex buffer.

procedure Init; virtual;

procedure InitVertexFormat(Format: Integer); virtual;

Init internal variables for the specified vertex format

procedure Invalidate(ABuffer: TTesselationBufferSet; EntireBuffer: Boolean);

Invalidates contents of buffers used by the tesselator at the API side. If EntireBuffer is True entire API buffer will become invalid so use only if necessary.

procedure InvalidateBoundingBox;

Informs engine core about bounding box change

procedure SetIndex(AValue, AOffset: Integer; AIBuf: Pointer);

Sets an index in index buffer

function SetIndices(IBPTR: Pointer): Integer; virtual;

procedure SetProperties(Properties: Props.TProperties); virtual;

Can be overridden to set some properties in addition to ones of a visible item which uses the tesselator. Called from SetProperties of TVisible. Object links can not be used or resolved here.

procedure SetVertexData2UV(u, v: Single; Index: Integer; VBuf: Pointer);

Set second 2D-texture coordinates set in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataC(x, y, z: Single; Index: Integer; VBuf: Pointer); overload;

Set a coordinate set in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataC(const Vec: TVector3s; Index: Integer; VBuf: Pointer); overload;

Set a coordinate set in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataCRHW(x, y, z, RHW: Single; Index: Integer; VBuf: Pointer);

Set a transformed coordinate set in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataD(Color: TColor; Index: Integer; VBuf: Pointer);

Set a diffuse color (color 1) in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataN(nx, ny, nz: Single; Index: Integer; VBuf: Pointer); overload;

Set a normal in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataN(const Vec: TVector3s; Index: Integer; VBuf: Pointer); overload;

Set a normal in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataS(Color: TColor; Index: Integer; VBuf: Pointer);

Set a specular color (color 2) in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataUV(u, v: Single; Index: Integer; VBuf: Pointer);

Set first 2D-texture coordinates set in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataUV3(u, v, w: Single; Index: Integer; VBuf: Pointer);

Set first 3D-texture coordinates set in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

procedure SetVertexDataW(w: Single; Index: Integer; VBuf: Pointer);

Set a weight in vertex buffer. [b]Index[/b] - element index, [b]VBuf[/b] - pointer to vertex buffer. Should be called from Tesselate only

function Tesselate(const Params: TTesselationParameters; VBPTR: Pointer): Integer; virtual;

function Validate: Boolean; virtual;

Returns True if mesh is valid. The basic implemetation simply tests all indices to point within correct vertices range.

Properties

Overview

	`property VertexFormat: Integer;`
	`property VertexSize: Integer;`

Description

property VertexFormat: Integer;

Output format of vertices

property VertexSize: Integer;

Size of each vertex