AtlasImage Struct Reference

An Image packed into an ImageAtlas. More...

#include <AtlasImage.h>

Inheritance diagram for AtlasImage:

Public Member Functions
Class *	_AtlasImage (void)
AtlasImage *	initWithImage (AtlasImage *self, ImageAtlas *atlas, Image *image)
	Initializes this AtlasImage with the given Image's surface.
SDL_FRect	texcoords (const AtlasImage *self)
	Resolves this AtlasImage's normalized texture coordinates within the atlas Texture.
Public Member Functions inherited from Image
Class *	_Image (void)
	The Image archetype.
Image *	imageWithBytes (const uint8_t *bytes, size_t length)
	Instantiates an Image with the specified bytes.
Image *	imageWithData (const Data *data)
	Instantiates an Image with the specified Data.
Image *	imageWithResource (const Resource *resource)
	Instantiates an Image with the specified Resource.
Image *	imageWithResourceName (const char *name)
	Instantiates an Image with the specified Resource name.
Image *	imageWithSurface (SDL_Surface *surface)
	Instantiates an Image with the specified surface.
Image *	imageWithSVG (const uint8_t *bytes, size_t length, float scale)
	Instantiates an Image by rasterizing the specified SVG.
Image *	initWithBytes (Image *self, const uint8_t *bytes, size_t length)
	Initializes this Image with the specified bytes.
Image *	initWithData (Image *self, const Data *data)
	Initializes this Image with the specified Data.
Image *	initWithResource (Image *self, const Resource *resource)
	Initializes this Image with the specified Resource.
Image *	initWithResourceName (Image *self, const char *name)
	Initializes this Image, loading the Resource by the given name.
Image *	initWithSurface (Image *self, SDL_Surface *surface)
	Initializes this Image with the given surface.
Image *	initWithSVG (Image *self, const uint8_t *bytes, size_t length, float scale)
	Initializes this Image by rasterizing the specified SVG at its intrinsic size times scale.
Image *	initWithSVGSize (Image *self, const uint8_t *bytes, size_t length, SDL_Size points)
	Initializes this Image by rasterizing the specified SVG at points times the pixel density, so that Image::size reports points.
SDL_Size	size (const Image *self)

Data Fields
ImageAtlas *	atlas
	The ImageAtlas this AtlasImage belongs to, or NULL once that atlas has been released, after which this AtlasImage draws nothing.
Image	image
	The superclass.
SDL_Rect	rect
	This AtlasImage's rectangle within the atlas sheet, in texels.
Data Fields inherited from Image
Object	object
	The superclass.
float	scale
	Pixels of surface per point: 1 for raster images, the requested scale for SVG.
SDL_Surface *	surface
	The backing surface.
const char *	type
	The image type, inferred if instantiated with a Resource.

Protected Attributes
AtlasImageInterface *	interface [0]
	The interface type.
Protected Attributes inherited from Image
ImageInterface *	interface [0]
	The interface type.

Detailed Description

An Image packed into an ImageAtlas.

An AtlasImage keeps its source surface, so Image::size and anything else that reads surface behave as for a standalone Image. What it adds is where those pixels landed in the atlas sheet, so that a View drawing it samples the atlas Texture rather than a Texture of its own, and consecutive draws from the same atlas merge into one call.

Definition at line 41 of file AtlasImage.h.

Member Function Documentation

_AtlasImage()

Class * _AtlasImage

(

void

)

Definition at line 84 of file AtlasImage.c.

                         {
  static Class *clazz;
  static Once once;
 
  do_once(&once, {
    clazz = _initialize(&(const ClassDef) {
      .name = "AtlasImage",
      .superclass = _Image(),
      .instanceSize = sizeof(AtlasImage),
      .interfaceSize = sizeof(AtlasImageInterface),
      .initialize = initialize,
    });
  });
 
  return clazz;
}

initWithImage()

AtlasImage * initWithImage	(	AtlasImage *	self,
		ImageAtlas *	atlas,
		Image *	image
	)

Initializes this AtlasImage with the given Image's surface.

Parameters

self	The AtlasImage.
atlas	The ImageAtlas.
image	The Image.

Returns

The initialized AtlasImage, or NULL on error.

Remarks

Use ImageAtlas::addImage; the atlas creates and owns its AtlasImages.

Definition at line 32 of file AtlasImage.c.

                                                                                    {
 
  assert(atlas);
  assert(image);
  assert(image->surface);
 
  self = (AtlasImage *) super(Image, self, initWithSurface, image->surface);
  if (self) {
    self->image.scale = image->scale;
    self->atlas = atlas;
    self->rect = (SDL_Rect) { 0, 0, 0, 0 };
  }
 
  return self;
}

texcoords()

SDL_FRect texcoords

(

const AtlasImage *

self

)

Resolves this AtlasImage's normalized texture coordinates within the atlas Texture.

Parameters

self	The AtlasImage.

Returns

The texture coordinates, or an empty rectangle if the atlas has not been compiled or has been released.

Definition at line 52 of file AtlasImage.c.

                                                   {
 
  const Image *sheet = self->atlas ? self->atlas->image : NULL;
  if (sheet == NULL) {
    return (SDL_FRect) { 0.f, 0.f, 0.f, 0.f };
  }
 
  const float w = (float) sheet->surface->w, h = (float) sheet->surface->h;
 
  return (SDL_FRect) {
    self->rect.x / w,
    self->rect.y / h,
    self->rect.w / w,
    self->rect.h / h
  };
}

Field Documentation

atlas

ImageAtlas* AtlasImage::atlas

The ImageAtlas this AtlasImage belongs to, or NULL once that atlas has been released, after which this AtlasImage draws nothing.

Remarks

Weak: the atlas owns its AtlasImages, and clears this on dealloc.

Definition at line 59 of file AtlasImage.h.

image

Image AtlasImage::image

The superclass.

Definition at line 46 of file AtlasImage.h.

interface

AtlasImageInterface* AtlasImage::interface[0]

protected

The interface type.

Definition at line 52 of file AtlasImage.h.

rect

SDL_Rect AtlasImage::rect

This AtlasImage's rectangle within the atlas sheet, in texels.

Remarks

Assigned by ImageAtlas::compile, and reassigned by every subsequent compile, so it MUST be read at draw time rather than cached.

Definition at line 66 of file AtlasImage.h.

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The documentation for this struct was generated from the following files:

• Sources/ObjectivelyMVC/AtlasImage.h
• Sources/ObjectivelyMVC/AtlasImage.c