ref: 757429fdc9deda34c458a251fdfd35e080dc19ac
dir: /demos/graph/grdevice.c/
#include "grobjs.h"
#include "grdevice.h"
#include <stdlib.h>
#include <string.h>
grDeviceChain gr_device_chain[ GR_MAX_DEVICES ];
int gr_num_devices = 0;
static
grDevice* find_device( const char* device_name )
{
int index = 0;
if (device_name)
{
for ( index = gr_num_devices-1; index > 0; index-- )
if ( strcmp( device_name, gr_device_chain[index].name ) == 0 )
break;
}
if ( index < 0 || gr_num_devices <= 0 || !gr_device_chain[index].device )
{
grError = gr_err_invalid_device;
return 0;
}
return gr_device_chain[index].device;
}
/**********************************************************************
*
* <Function>
* grGetDeviceModes
*
* <Description>
* queries the available pixel modes for a device.
*
* <Input>
* device_name :: name of device to be used. 0 for the default
* device. For a list of available devices, see
* grInitDevices.
*
* <Output>
* num_modes :: number of available modes. 0 in case of error,
* which really is an invalid device name.
*
* pixel_modes :: array of available pixel modes for this device
* this table is internal to the device and should
* not be freed by client applications.
*
* <Return>
* error code. 0 means success. invalid device name otherwise
*
* <Note>
* All drivers are _required_ to support at least the following
* pixel formats :
*
* - gr_pixel_mode_mono : i.e. monochrome bitmaps
* - gr_pixel_mode_gray : with any number of gray levels between
* 2 and 256.
*
* the pixel modes do not provide the number of grays in the case
* of "gray" devices. You should try to create a surface with the
* maximal number (256, that is) and see the value returned in
* the bitmap descriptor.
*
**********************************************************************/
extern void grGetDeviceModes( const char* device_name,
int *num_modes,
grPixelMode* *pixel_modes )
{
grDevice* device;
*num_modes = 0;
*pixel_modes = 0;
device = find_device( device_name );
if (device)
{
*num_modes = device->num_pixel_modes;
*pixel_modes = device->pixel_modes;
}
}
/**********************************************************************
*
* <Function>
* grNewSurface
*
* <Description>
* creates a new device-specific surface. A surface is either
* a window or a screen, depending on the device.
*
* <Input>
* device :: name of the device to use. A value of NULL means
* the default device (which depends on the system).
* for a list of available devices, see grInitDevices.
*
* <InOut>
* bitmap :: handle to a bitmap descriptor containing the
* requested pixel mode, number of grays and dimensions
* for the surface. the bitmap's 'pitch' and 'buffer'
* fields are ignored on input.
*
* On output, the bitmap describes the surface's image
* completely. It is possible to write directly in it
* with grBlitGlyphToBitmap, even though the use of
* grBlitGlyphToSurface is recommended.
*
* <Return>
* handle to the corresponding surface object. 0 in case of error
*
* <Note>
* All drivers are _required_ to support at least the following
* pixel formats :
*
* - gr_pixel_mode_mono : i.e. monochrome bitmaps
* - gr_pixel_mode_gray : with any number of gray levels between
* 2 and 256.
*
* This function might change the bitmap descriptor's fields. For
* example, when displaying a full-screen surface, the bitmap's
* dimensions will be set to those of the screen (e.g. 640x480
* or 800x600); also, the bitmap's 'buffer' field might point to
* the Video Ram depending on the mode requested..
*
* The surface contains a copy of the returned bitmap descriptor,
* you can thus discard the 'bitmap' parameter after the call.
*
**********************************************************************/
extern grSurface* grNewSurface( const char* device_name,
grBitmap* bitmap )
{
grDevice* device;
grSurface* surface;
/* Now find the device */
device = find_device( device_name );
if (!device) return 0;
surface = (grSurface*)grAlloc( device->surface_objsize );
if (!surface) return 0;
if ( !device->init_surface( surface, bitmap ) )
{
grFree( surface );
surface = 0;
}
return surface;
}
/**********************************************************************
*
* <Function>
* grRefreshRectangle
*
* <Description>
* this function is used to indicate that a given surface rectangle
* was modified and thus needs re-painting. It really is useful for
* windowed or gray surfaces.
*
* <Input>
* surface :: handle to target surface
* x :: x coordinate of the top-left corner of the rectangle
* y :: y coordinate of the top-left corner of the rectangle
* width :: rectangle width in pixels
* height :: rectangle height in pixels
*
**********************************************************************/
extern void grRefreshRectangle( grSurface* surface,
grPos x,
grPos y,
grPos width,
grPos height )
{
if (surface->refresh_rect)
surface->refresh_rect( surface, x, y, width, height );
}
/**********************************************************************
*
* <Function>
* grWriteSurfaceChar
*
* <Description>
* This function is equivalent to calling grWriteCellChar on the
* surface's bitmap, then invoking grRefreshRectangle.
*
* The graphics sub-system contains an internal Latin1 8x8 font
* which can be used to display simple strings of text without
* using FreeType.
*
* This function writes a single 8x8 character on the target bitmap.
*
* <Input>
* target :: handle to target surface
* x :: x pixel position of character cell's top left corner
* y :: y pixel position of character cell's top left corner
* charcode :: Latin-1 character code
* color :: color to be used to draw the character
*
**********************************************************************/
extern
void grWriteSurfaceChar( grSurface* target,
int x,
int y,
int charcode,
grColor color )
{
grWriteCellChar( &target->bitmap, x, y, charcode, color );
if (target->refresh_rect)
target->refresh_rect( target, x, y, 8, 8 );
}
/**********************************************************************
*
* <Function>
* grWriteSurfaceString
*
* <Description>
* This function is equivalent to calling grWriteCellString on the
* surface's bitmap, then invoking grRefreshRectangle.
*
* The graphics sub-system contains an internal Latin1 8x8 font
* which can be used to display simple strings of text without
* using FreeType.
*
* This function writes a string with the internal font
*
* <Input>
* target :: handle to target bitmap
* x :: x pixel position of string's top left corner
* y :: y pixel position of string's top left corner
* string :: Latin-1 text string
* color :: color to be used to draw the character
*
**********************************************************************/
extern
void grWriteSurfaceString( grSurface* target,
int x,
int y,
const char* string,
grColor color )
{
int len;
len = strlen(string);
grWriteCellString( &target->bitmap, x, y, string, color );
if (target->refresh_rect)
target->refresh_rect( target, x, y, 8*len, 8 );
}
/**********************************************************************
*
* <Function>
* grRefreshSurface
*
* <Description>
* a variation of grRefreshRectangle which repaints the whole surface
* to the screen.
*
* <Input>
* surface :: handle to target surface
*
**********************************************************************/
extern void grRefreshSurface( grSurface* surface )
{
if (surface->refresh_rect)
surface->refresh_rect( surface, 0, 0,
surface->bitmap.width,
surface->bitmap.rows );
}
/**********************************************************************
*
* <Function>
* grSetTitle
*
* <Description>
* set the window title of a given windowed surface.
*
* <Input>
* surface :: handle to target surface
* title_string :: the new title
*
**********************************************************************/
extern void grSetTitle( grSurface* surface,
const char* title_string )
{
if (surface->set_title)
surface->set_title( surface, title_string );
}
/**********************************************************************
*
* <Function>
* grListenSurface
*
* <Description>
* listen the events for a given surface
*
* <Input>
* surface :: handle to target surface
* event_mask :: the event mask (mode)
*
* <Output>
* event :: the returned event
*
* <Note>
* XXX : For now, only keypresses are supported.
*
**********************************************************************/
extern
int grListenSurface( grSurface* surface,
int event_mask,
grEvent *event )
{
return surface->listen_event( surface, event_mask, event );
}
#if 0
static
void gr_done_surface( grSurface* surface )
{
if (surface)
{
/* first of all, call the device-specific destructor */
surface->done(surface);
/* then remove the bitmap if we're owner */
if (surface->owner)
grFree( surface->bitmap.buffer );
surface->owner = 0;
surface->bitmap.buffer = 0;
grFree( surface );
}
}
#endif