RETROFLAT_VIEWPORT Struct Reference

The viewport data struct. More...

#include <retroflt.h>

Data Fields
int16_t	screen_x
	X position of the viewport in real screen memory in pixels. Should only be retrieved through retroflat_viewport_screen_x() and set through retroflat_viewport_set_pos_size().
int16_t	screen_y
	Y position of the viewport in real screen memory in pixels. Should only be retrieved through retroflat_viewport_screen_y() and set through retroflat_viewport_set_pos_size()
int16_t	world_x
	The X offset, in pixels, of the viewport on the world tilemap. Should only be retrieved through retroflat_viewport_world_x() and set through retroflat_viewport_set_world_pos().
int16_t	world_y
	The Y offset, in pixels, of the viewport on the world tilemap. Should only be retrieved through retroflat_viewport_world_y() and set through retroflat_viewport_set_world_pos().
int16_t	world_w
	The width of the entire world tilemap in pixels. Should only be retrieved through retroflat_viewport_world_w() and set through retroflat_viewport_set_world().
int16_t	world_h
	The height of the entire world tilemap in pixels. Should only be retrieved through retroflat_viewport_world_h() and set through retroflat_viewport_set_world().
uint16_t	screen_w
	Viewport width in pixels. Should only be retrieved through retroflat_viewport_screen_w() and set through retroflat_viewport_set_pos_size().
uint16_t	screen_h
	Viewport height in pixels. Should only be retrieved through retroflat_viewport_screen_w() and set through retroflat_viewport_set_pos_size().
uint16_t	screen_w_remainder
	Difference between viewport width and screen width in pixels. Should only be retrieved through retroflat_viewport_screen_w_remainder() and calculated through retroflat_viewport_set_pos_size().
uint16_t	screen_h_remainder
	Difference between viewport height and screen height in pixels. Should only be retrieved through retroflat_viewport_screen_h_remainder() and calculated through retroflat_viewport_set_pos_size().
int16_t	screen_tile_w
	The number of tiles across that fit in the viewport. Should only be retrieved through retroflat_viewport_screen_tile_w() and calculated through retroflat_viewport_set_pos_size().
int16_t	screen_tile_h
	The number of tiles high that fit in the viewport. Should only be retrieved through retroflat_viewport_screen_tile_h() and calculated through retroflat_viewport_set_pos_size().
int16_t	world_tile_x
int16_t	world_tile_y
MAUG_MHANDLE	refresh_grid_h
retroflat_tile_t *	refresh_grid
	A grid of tile values representing the last-drawn values on-screen. More...

Related Functions
(Note that these are not member functions.)
#define	retroflat_viewport_world_x()
	Return the current viewport X position in the world in pixels. More...
#define	retroflat_viewport_world_y()
	Return the current viewport Y position in the world in pixels. More...
#define	retroflat_viewport_world_w()    retroflat_viewport_world_w_generic()
	Return the current width of the world in pixels.
#define	retroflat_viewport_world_h()    retroflat_viewport_world_h_generic()
	Return the current height of the world in pixels.
#define	retroflat_viewport_screen_tile_w()    retroflat_viewport_screen_tile_w_generic()
	Return the current width of the world in tiles.
#define	retroflat_viewport_screen_tile_h()    retroflat_viewport_screen_tile_h_generic()
	Return the current height of the world in tiles.
#define	retroflat_viewport_screen_w()    retroflat_viewport_screen_w_generic()
	Return the width of the viewport in pixels.
#define	retroflat_viewport_screen_h()    retroflat_viewport_screen_h_generic()
	Return the height of the viewport in pixels.
#define	retroflat_viewport_screen_w_remainder()    retroflat_viewport_screen_w_remainder_generic()
	Return the difference in pixels between the viewport X + width and the screen width.
#define	retroflat_viewport_screen_h_remainder()    retroflat_viewport_screen_h_remainder_generic()
	Return the difference in pixels between the viewport Y + height and the screen height.
#define	retroflat_viewport_set_world(w, h)    retroflat_viewport_set_world_generic( w, h )
	Set the pixel width and height of the world so the viewport knows how far it may scroll. More...
#define	retroflat_viewport_set_world_pos(x, y)    retroflat_viewport_set_world_pos_generic( x, y )
	Set the position of the viewport in the world in pixels.
#define	retroflat_viewport_set_pos_size(x_px, y_px, w_px, h_px)    retroflat_viewport_set_pos_size_generic( x_px, y_px, w_px, h_px )
	Set the pixel width and height of the viewport, as well as some other dependent values frequently used in screen updates.
#define	retroflat_viewport_lock_refresh()    retroflat_viewport_lock_refresh_generic()
	Lock access to RETROFLAT_VIEWPORT::refresh_grid in memory. More...
#define	retroflat_viewport_unlock_refresh()    retroflat_viewport_unlock_refresh_generic()
	Unlock access to RETROFLAT_VIEWPORT::refresh_grid in memory. More...
#define	retroflat_viewport_set_refresh(x, y, tid)    retroflat_viewport_set_refresh_generic( x, y, tid )
	Set the tile at the given screen pixel coordinates to the given tile ID. More...

Detailed Description

The viewport data struct.

Warning

Many of the fields in this struct are calculated based on each other, and so updates should only be made through retroflat_viewport_set_pos_size()!

Friends And Related Function Documentation

retroflat_viewport_lock_refresh

#define retroflat_viewport_lock_refresh ( )     retroflat_viewport_lock_refresh_generic()

related

Lock access to RETROFLAT_VIEWPORT::refresh_grid in memory.

This should be called before making references to the refresh grid e.g. with retroflat_viewport_tile_is_stale().

retroflat_viewport_set_refresh

#define retroflat_viewport_set_refresh (   x,   y,   tid  )     retroflat_viewport_set_refresh_generic( x, y, tid )

related

Set the tile at the given screen pixel coordinates to the given tile ID.

If these coordinates are from the world, they should subtract retroflat_viewport_screen_x()/retroflat_viewport_screen_y() first!

When the viewport is redrawn, e.g. with retrotile_topdown_draw(), it will not redraw this tile if the tile ID is still the same.

retroflat_viewport_set_world

#define retroflat_viewport_set_world (   w,   h  )     retroflat_viewport_set_world_generic( w, h )

related

Set the pixel width and height of the world so the viewport knows how far it may scroll.

Parameters

w	The width of the world in pixels (tile_width * map_tile_width).
h	The height of the world in pixels (tile_height * map_tile_height).

retroflat_viewport_unlock_refresh

#define retroflat_viewport_unlock_refresh ( )     retroflat_viewport_unlock_refresh_generic()

related

Unlock access to RETROFLAT_VIEWPORT::refresh_grid in memory.

This should be called when references to the refresh grid are no longer in use and may be invalidated by the system.

retroflat_viewport_world_x

#define retroflat_viewport_world_x ( )

related

Value:

         ((retroflat_viewport_world_x_generic() \
            >> RETROFLAT_TILE_W_BITS) << RETROFLAT_TILE_W_BITS)

Return the current viewport X position in the world in pixels.

retroflat_viewport_world_y

#define retroflat_viewport_world_y ( )

related

Value:

         ((retroflat_viewport_world_y_generic() \
            >> RETROFLAT_TILE_H_BITS) << RETROFLAT_TILE_H_BITS)

Return the current viewport Y position in the world in pixels.

Field Documentation

refresh_grid

retroflat_tile_t* RETROFLAT_VIEWPORT::refresh_grid

A grid of tile values representing the last-drawn values on-screen.

If the value for a tile in this grid matches the value about to be drawn, the draw will be skipped. This increases performance a LOT on systems with slow video memory access.

This functionality may be disabled by defining the macro RETROFLAT_NO_VIEWPORT_REFRESH on build.

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

• retroflt.h