Public	`destructor Destroy; override;`
Public	`function Dimensions: TVector3Cardinal;`
Public	`function IsEmpty: boolean;`
Public	`function Rect: TRectangle;`
Public	`function ToFpImage: TInternalCastleFpImage; virtual; deprecated 'interoperability with FpImage may be dropped in the future';`
Public	`constructor Create(const AWidth, AHeight, ADepth: Cardinal; const ACompression: TTextureCompression);`
Public	`function Size: Cardinal; override;`
Public	`function HasAlpha: boolean; override;`
Public	`function AlphaChannel( const AlphaTolerance: Byte): TAlphaChannel; override;`
Public	`procedure FlipVertical; override;`
Public	`function Decompress: TCastleImage;`
Public	`function MakeCopy: TGPUCompressedImage;`
Public	`function CreateCopy: TEncodedImage; override;`

Properties

Public	`property Url: String read FUrl write FUrl;`
Public	`property Width: Cardinal read FWidth;`
Public	`property Height: Cardinal read FHeight;`
Public	`property Depth: Cardinal read FDepth;`
Public	`property RawPixels: Pointer read FRawPixels;`
Public	`property Compression: TTextureCompression read FCompression;`

Description

Fields

Protected FRawPixels: Pointer;

This item is declared in ancestor TEncodedImage.

Operate on this by Get/Realloc/FreeMem. It's always freed and nil'ed in destructor.

Source: images/castleimages.pas (line 183).

Methods

Public destructor Destroy; override;

This item is declared in ancestor TEncodedImage.

This item has no description.

Source: images/castleimages.pas (line 188).

Public function Dimensions: TVector3Cardinal;

This item is declared in ancestor TEncodedImage.

Get a 3D vector with Width, Height, Depth.

Source: images/castleimages.pas (line 230).

Public function IsEmpty: boolean;

This item is declared in ancestor TEncodedImage.

Is an image empty.

True means that RawPixels = Nil, and Width * Height * Depth = 0 (so either Width = 0 or Height = 0 or Depth = 0).

False means that RawPixels <> nil and Width * Height * Depth <> 0 (so all Width > 0 and Height > 0 and Depth > 0, since they are Cardinal (unsigned) always).

Source: images/castleimages.pas (line 241).

Public function Rect: TRectangle;

This item is declared in ancestor TEncodedImage.

Rectangle representing the inside of this image. Always (Left,Bottom) are zero, and (Width,Height) correspond to image sizes.

Source: images/castleimages.pas (line 293).

Public function ToFpImage: TInternalCastleFpImage; virtual; deprecated 'interoperability with FpImage may be dropped in the future';

This item is declared in ancestor TEncodedImage.

Warning: this symbol is deprecated: interoperability with FpImage may be dropped in the future

Convert image contents to FpImage instance. The resulting instance is owned by the caller.

Source: images/castleimages.pas (line 305).

Public constructor Create(const AWidth, AHeight, ADepth: Cardinal; const ACompression: TTextureCompression);

This item has no description.

Source: images/castleimages_class_gpu_compressed.inc (line 24).

Public function Size: Cardinal; override;

Size of the whole image data inside RawPixels, in bytes.

Source: images/castleimages_class_gpu_compressed.inc (line 30).

Public function HasAlpha: boolean; override;

This item has no description. Showing description inherited from TEncodedImage.HasAlpha.

Does an image have an alpha channel.

You may also be interested in the AlphaChannel that can make a distinction between alpha channel for blending and for alpha test. AlphaChannel answers always atNone if HasAlpha = false, and always acTest or acBlending if HasAlpha = true. But AlphaChannel may perform longer analysis of pixels (to differ between acTest and acBlending), while this function always executes ultra-fast (as it's constant for each TCastleImage descendant).

Descendants implementors notes: in this class, TCastleImage, this returns False. Override to return True for images with alpha channel.

Source: images/castleimages_class_gpu_compressed.inc (line 32).

Public function AlphaChannel( const AlphaTolerance: Byte): TAlphaChannel; override;

This item has no description. Showing description inherited from TEncodedImage.AlphaChannel.

Analyze image contents to determine if, and what kind, of alpha channel it has.

This may be a time-consuming operation. When the image has alpha channel and we need to decide whether it's suitable for "alpha test" (only fully opaque or fully transparent pixels) or "alpha blending" (any alpha value makes sense) then this method needs to iterate over image pixels.

For this reason, the result of this operation is cached at various levels, e.g. TImageTextureNode and TDrawableImage cache it internally.

We determine "alpha test - simple yes/no alpha channel" if all the alpha values (for every pixel) are 0, or 255, or (when AlphaTolerance <> 0) are close to them by AlphaTolerance. So, to be precise, alpha value must be <= AlphaTolerance, or >= 255 - AlphaTolerance. If any alpha value is between [AlphaTolerance + 1, 255 - AlphaTolerance - 1] then we return "alpha blending - full range alpha channel".

Note that big values of AlphaTolerance make it easier to quality image as "alpha test - simple yes/no alpha channel". When AlphaTolerance >= 128, all images are treated as "simple yes/no alpha". Usually, you want to keep AlphaTolerance small.

Descendants implementors notes: in this class, this simply always returns atNone. For descendants that have alpha channel, implement it, honouring AlphaTolerance as described.

Source: images/castleimages_class_gpu_compressed.inc (line 33).

Public procedure FlipVertical; override;

Flip compressed image vertically, losslessly.

This works only for S3TC images, and only when their height is 1, 2, 3 or a multiple of 4. Note that this is always satisfied if image height is a power of two (as common for textures). It uses the knowledge of how S3TC compression works to losslessly flip the image, without re-compressing it. The idea is described here [http://users.telenet.be/tfautre/softdev/ddsload/explanation.htm].

Source: images/castleimages_class_gpu_compressed.inc (line 45).

Public function Decompress: TCastleImage;

Decompress the image.

This uses DecompressTexture routine. By default, it is assigned only when OpenGL(ES) context is available and can decompress textures with the help of OpenGL(ES).

Exceptions raised

ECannotDecompressTexture: If we cannot decompress the texture, because decompressor is not set or there was some other error within decompressor.

Source: images/castleimages_class_gpu_compressed.inc (line 56).

Public function MakeCopy: TGPUCompressedImage;

Create a new image object that has exactly the same class and the same data (size, pixels) as this image.

Source: images/castleimages_class_gpu_compressed.inc (line 60).

Public function CreateCopy: TEncodedImage; override;

Create a new image object that has exactly the same class and the same data (size, pixels) as this image.

Equivalent to MakeCopy, but virtual and declared as returning TEncodedImage class.

Source: images/castleimages_class_gpu_compressed.inc (line 66).

Properties

Public property Url: String read FUrl write FUrl;

This item is declared in ancestor TEncodedImage.

Url from which this image was loaded, if any.

Source: images/castleimages.pas (line 186).

Public property Width: Cardinal read FWidth;

This item is declared in ancestor TEncodedImage.

This item has no description.

Source: images/castleimages.pas (line 190).

Public property Height: Cardinal read FHeight;

This item is declared in ancestor TEncodedImage.

This item has no description.

Source: images/castleimages.pas (line 191).

Public property Depth: Cardinal read FDepth;

This item is declared in ancestor TEncodedImage.

Depth of the image. For 2D images (most common) this is just 1.

All images in CastleImages can be potentially 3D, which means they can have Depth > 1. A 3D image is just a 3-dimensional array of pixels, and you can use it e.g. as a texture with 3D texture coordinates. A sample use-cases for 3D textures are:

Generated colors of some material that you can imagine as a 3D volume, like a volume of wood or marble. This is nice to apply on any complicated 3D shape, because the necessary 3D texture coordinates are trivial, since 3D position of a point on the shape can be used as a reasonable 3D texture coordinate.
Medical data, some scans are 3D.
Noise (like Perlin noise) used for various effects in shaders.
Specialized noise, e.g. a volume of smoke, or a volume of clouds.

Source: images/castleimages.pas (line 215).

Public property RawPixels: Pointer read FRawPixels;

This item is declared in ancestor TEncodedImage.

Image data. The layout of this memory is defined by descendants. For example, for TCastleImage it's a simple array of pixels (see TCastleImage docs for exact description of the memory layout), for TGPUCompressedImage it's a compressed data for GPU.

Note that this may be Nil, if Width * Height * Depth = 0. In this case, IsEmpty returns True.

Source: images/castleimages.pas (line 224).

Public property Compression: TTextureCompression read FCompression;

This item has no description.

Source: images/castleimages_class_gpu_compressed.inc (line 27).

Generated by PasDoc 0.17.0.snapshot.

Castle Game Engine

API Reference

Class TGPUCompressedImage

Unit

Declaration

Description

Hierarchy

Overview

Fields

Methods

Properties

Description

Fields

Methods

Exceptions raised

Properties