OpenTTD Source  20241108-master-g80f628063a
Blitter Class Referenceabstract

How all blitters should look like. More...

#include <base.hpp>

Inheritance diagram for Blitter:
SpriteEncoder Blitter_32bppBase Blitter_8bppBase Blitter_Null Blitter_32bppSimple Blitter_8bppOptimized Blitter_8bppSimple Blitter_32bppOptimized Blitter_32bppAnim Blitter_40bppAnim

Data Structures

struct  BlitterParams
 Parameters related to blitting. More...
 

Public Types

enum  PaletteAnimation { PALETTE_ANIMATION_NONE , PALETTE_ANIMATION_VIDEO_BACKEND , PALETTE_ANIMATION_BLITTER }
 Types of palette animation. More...
 

Public Member Functions

virtual uint8_t GetScreenDepth ()=0
 Get the screen depth this blitter works for. More...
 
bool Is32BppSupported () override
 Can the sprite encoder make use of RGBA sprites?
 
virtual void Draw (Blitter::BlitterParams *bp, BlitterMode mode, ZoomLevel zoom)=0
 Draw an image to the screen, given an amount of params defined above.
 
virtual void DrawColourMappingRect (void *dst, int width, int height, PaletteID pal)=0
 Draw a colourtable to the screen. More...
 
virtual void * MoveTo (void *video, int x, int y)=0
 Move the destination pointer the requested amount x and y, keeping in mind any pitch and bpp of the renderer. More...
 
virtual void SetPixel (void *video, int x, int y, uint8_t colour)=0
 Draw a pixel with a given colour on the video-buffer. More...
 
virtual void DrawRect (void *video, int width, int height, uint8_t colour)=0
 Make a single horizontal line in a single colour on the video-buffer. More...
 
virtual void DrawLine (void *video, int x, int y, int x2, int y2, int screen_width, int screen_height, uint8_t colour, int width, int dash=0)=0
 Draw a line with a given colour. More...
 
virtual void CopyFromBuffer (void *video, const void *src, int width, int height)=0
 Copy from a buffer to the screen. More...
 
virtual void CopyToBuffer (const void *video, void *dst, int width, int height)=0
 Copy from the screen to a buffer. More...
 
virtual void CopyImageToBuffer (const void *video, void *dst, int width, int height, int dst_pitch)=0
 Copy from the screen to a buffer in a palette format for 8bpp and RGBA format for 32bpp. More...
 
virtual void ScrollBuffer (void *video, int &left, int &top, int &width, int &height, int scroll_x, int scroll_y)=0
 Scroll the videobuffer some 'x' and 'y' value. More...
 
virtual size_t BufferSize (uint width, uint height)=0
 Calculate how much memory there is needed for an image of this size in the video-buffer. More...
 
virtual void PaletteAnimate (const Palette &palette)=0
 Called when the 8bpp palette is changed; you should redraw all pixels on the screen that are equal to the 8bpp palette indexes 'first_dirty' to 'first_dirty + count_dirty'. More...
 
virtual Blitter::PaletteAnimation UsePaletteAnimation ()=0
 Check if the blitter uses palette animation at all. More...
 
virtual bool NeedsAnimationBuffer ()
 Does this blitter require a separate animation buffer from the video backend?
 
virtual std::string_view GetName ()=0
 Get the name of the blitter, the same as the Factory-instance returns.
 
virtual void PostResize ()
 Post resize event.
 
template<typename SetPixelT >
void DrawLineGeneric (int x, int y, int x2, int y2, int screen_width, int screen_height, int width, int dash, SetPixelT set_pixel)
 
- Public Member Functions inherited from SpriteEncoder
virtual SpriteEncode (const SpriteLoader::SpriteCollection &sprite, SpriteAllocator &allocator)=0
 Convert a sprite from the loader to our own format.
 
virtual uint GetSpriteAlignment ()
 Get the value which the height and width on a sprite have to be aligned by. More...
 

Detailed Description

How all blitters should look like.

Extend this class to make your own.

Definition at line 29 of file base.hpp.

Member Enumeration Documentation

◆ PaletteAnimation

Types of palette animation.

Enumerator
PALETTE_ANIMATION_NONE 

No palette animation.

PALETTE_ANIMATION_VIDEO_BACKEND 

Palette animation should be done by video backend (8bpp only!)

PALETTE_ANIMATION_BLITTER 

The blitter takes care of the palette animation.

Definition at line 50 of file base.hpp.

Member Function Documentation

◆ BufferSize()

virtual size_t Blitter::BufferSize ( uint  width,
uint  height 
)
pure virtual

Calculate how much memory there is needed for an image of this size in the video-buffer.

Parameters
widthThe width of the buffer-to-be.
heightThe height of the buffer-to-be.
Returns
The size needed for the buffer.

Implemented in Blitter_Null, Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppBase, and Blitter_32bppAnim.

◆ CopyFromBuffer()

virtual void Blitter::CopyFromBuffer ( void *  video,
const void *  src,
int  width,
int  height 
)
pure virtual

Copy from a buffer to the screen.

Parameters
videoThe destination pointer (video-buffer).
srcThe buffer from which the data will be read.
widthThe width of the buffer.
heightThe height of the buffer.
Note
You can not do anything with the content of the buffer, as the blitter can store non-pixel data in it too!

Implemented in Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppBase, Blitter_32bppAnim, and Blitter_Null.

◆ CopyImageToBuffer()

virtual void Blitter::CopyImageToBuffer ( const void *  video,
void *  dst,
int  width,
int  height,
int  dst_pitch 
)
pure virtual

Copy from the screen to a buffer in a palette format for 8bpp and RGBA format for 32bpp.

Parameters
videoThe destination pointer (video-buffer).
dstThe buffer in which the data will be stored.
widthThe width of the buffer.
heightThe height of the buffer.
dst_pitchThe pitch (byte per line) of the destination buffer.

Implemented in Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppBase, and Blitter_Null.

◆ CopyToBuffer()

virtual void Blitter::CopyToBuffer ( const void *  video,
void *  dst,
int  width,
int  height 
)
pure virtual

Copy from the screen to a buffer.

Parameters
videoThe destination pointer (video-buffer).
dstThe buffer in which the data will be stored.
widthThe width of the buffer.
heightThe height of the buffer.
Note
You can not do anything with the content of the buffer, as the blitter can store non-pixel data in it too!

Implemented in Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppBase, Blitter_32bppAnim, and Blitter_Null.

◆ DrawColourMappingRect()

virtual void Blitter::DrawColourMappingRect ( void *  dst,
int  width,
int  height,
PaletteID  pal 
)
pure virtual

Draw a colourtable to the screen.

This is: the colour of the screen is read and is looked-up in the palette to match a new colour, which then is put on the screen again.

Parameters
dstthe destination pointer (video-buffer).
widththe width of the buffer.
heightthe height of the buffer.
palthe palette to use.

Implemented in Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppSimple, Blitter_32bppAnim, and Blitter_Null.

◆ DrawLine()

virtual void Blitter::DrawLine ( void *  video,
int  x,
int  y,
int  x2,
int  y2,
int  screen_width,
int  screen_height,
uint8_t  colour,
int  width,
int  dash = 0 
)
pure virtual

Draw a line with a given colour.

Parameters
videoThe destination pointer (video-buffer).
xThe x coordinate from where the line starts.
yThe y coordinate from where the line starts.
x2The x coordinate to where the line goes.
y2The y coordinate to where the lines goes.
screen_widthThe width of the screen you are drawing in (to avoid buffer-overflows).
screen_heightThe height of the screen you are drawing in (to avoid buffer-overflows).
colourA 8bpp mapping colour.
widthLine width.
dashLength of dashes for dashed lines. 0 means solid line.

Implemented in Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppBase, Blitter_32bppAnim, and Blitter_Null.

◆ DrawRect()

virtual void Blitter::DrawRect ( void *  video,
int  width,
int  height,
uint8_t  colour 
)
pure virtual

Make a single horizontal line in a single colour on the video-buffer.

Parameters
videoThe destination pointer (video-buffer).
widthThe length of the line.
heightThe height of the line.
colourA 8bpp mapping colour.

Implemented in Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppBase, Blitter_32bppAnim, and Blitter_Null.

◆ GetScreenDepth()

virtual uint8_t Blitter::GetScreenDepth ( )
pure virtual

◆ MoveTo()

virtual void* Blitter::MoveTo ( void *  video,
int  x,
int  y 
)
pure virtual

Move the destination pointer the requested amount x and y, keeping in mind any pitch and bpp of the renderer.

Parameters
videoThe destination pointer (video-buffer) to scroll.
xHow much you want to scroll to the right.
yHow much you want to scroll to the bottom.
Returns
A new destination pointer moved the the requested place.

Implemented in Blitter_8bppBase, Blitter_32bppBase, and Blitter_Null.

Referenced by SmallMapWindow::DrawSmallMapColumn().

◆ PaletteAnimate()

virtual void Blitter::PaletteAnimate ( const Palette palette)
pure virtual

Called when the 8bpp palette is changed; you should redraw all pixels on the screen that are equal to the 8bpp palette indexes 'first_dirty' to 'first_dirty + count_dirty'.

Parameters
paletteThe new palette.

Implemented in Blitter_8bppBase, Blitter_32bppBase, Blitter_32bppAnim, and Blitter_Null.

Referenced by VideoDriver_SDL_Default::Paint(), VideoDriver_SDL_OpenGL::Paint(), and VideoDriver_Win32GDI::Paint().

◆ ScrollBuffer()

virtual void Blitter::ScrollBuffer ( void *  video,
int &  left,
int &  top,
int &  width,
int &  height,
int  scroll_x,
int  scroll_y 
)
pure virtual

Scroll the videobuffer some 'x' and 'y' value.

Parameters
videoThe buffer to scroll into.
leftThe left value of the screen to scroll.
topThe top value of the screen to scroll.
widthThe width of the screen to scroll.
heightThe height of the screen to scroll.
scroll_xHow much to scroll in X.
scroll_yHow much to scroll in Y.

Implemented in Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppBase, Blitter_32bppAnim, and Blitter_Null.

◆ SetPixel()

virtual void Blitter::SetPixel ( void *  video,
int  x,
int  y,
uint8_t  colour 
)
pure virtual

Draw a pixel with a given colour on the video-buffer.

Parameters
videoThe destination pointer (video-buffer).
xThe x position within video-buffer.
yThe y position within video-buffer.
colourA 8bpp mapping colour.

Implemented in Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppBase, Blitter_32bppAnim, and Blitter_Null.

◆ UsePaletteAnimation()

virtual Blitter::PaletteAnimation Blitter::UsePaletteAnimation ( )
pure virtual

Check if the blitter uses palette animation at all.

Returns
True if it uses palette animation.

Implemented in Blitter_Null, Blitter_8bppBase, Blitter_40bppAnim, Blitter_32bppBase, and Blitter_32bppAnim.

Referenced by VideoDriver_SDL::CheckPaletteAnim(), VideoDriver_SDL_Default::Paint(), VideoDriver_SDL_OpenGL::Paint(), and VideoDriver_Win32GDI::Paint().


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