added copyright header

[taylor/freespace2.git] / include / 2d.h

/*
 * Copyright (C) Volition, Inc. 1999.  All rights reserved.
 *
 * All source code herein is the property of Volition, Inc. You may not sell 
 * or otherwise commercially exploit the source or things you created based on
 * the source.
 */

/*
 * $Logfile: /Freespace2/code/Graphics/2d.h $
 * $Revision$
 * $Date$
 * $Author$
 *
 * Header file for 2d primitives.
 *
 * $Log$
 * Revision 1.2  2002/06/09 04:41:12  relnev
 * added copyright header
 *
 * Revision 1.1.1.1  2002/05/03 03:28:12  root
 * Initial import.
 *
 * 
 * 16    8/30/99 5:01p Dave
 * Made d3d do less state changing in the nebula. Use new chat server for
 * PXO.
 * 
 * 15    8/16/99 9:45a Jefff
 * changes to cursor management to allow a 2nd temporary cursor
 * 
 * 14    7/15/99 3:07p Dave
 * 32 bit detection support. Mouse coord commandline.
 * 
 * 13    7/14/99 9:42a Dave
 * Put in clear_color debug function. Put in base for 3dnow stuff / P3
 * stuff
 * 
 * 12    7/09/99 9:51a Dave
 * Added thick polyline code.
 * 
 * 11    6/29/99 10:35a Dave
 * Interface polygon bitmaps! Whee!
 * 
 * 10    2/03/99 11:44a Dave
 * Fixed d3d transparent textures.
 * 
 * 9     1/30/99 5:08p Dave
 * More new hi-res stuff.Support for nice D3D textures.
 * 
 * 8     1/24/99 11:36p Dave
 * First full rev of beam weapons. Very customizable. Removed some bogus
 * Int3()'s in low level net code.
 * 
 * 7     12/21/98 5:02p Dave
 * Modified all hud elements to be multi-resolution friendly.
 * 
 * 6     12/18/98 1:49a Dave
 * Fixed Fred initialization problem resulting from hi-res mode changes.
 * 
 * 5     12/18/98 1:13a Dave
 * Rough 1024x768 support for Direct3D. Proper detection and usage through
 * the launcher.
 * 
 * 4     12/06/98 2:36p Dave
 * Drastically improved nebula fogging.
 * 
 * 3     11/11/98 5:37p Dave
 * Checkin for multiplayer testing.
 * 
 * 2     10/07/98 10:52a Dave
 * Initial checkin.
 * 
 * 1     10/07/98 10:48a Dave
 * 
 * 75    5/20/98 9:45p John
 * added code so the places in code that change half the palette don't
 * have to clear the screen.
 * 
 * 74    5/06/98 5:30p John
 * Removed unused cfilearchiver.  Removed/replaced some unused/little used
 * graphics functions, namely gradient_h and _v and pixel_sp.   Put in new
 * DirectX header files and libs that fixed the Direct3D alpha blending
 * problems.
 * 
 * 73    4/14/98 12:15p John
 * Made 16-bpp movies work.
 * 
 * 72    4/10/98 5:20p John
 * Changed RGB in lighting structure to be ubytes.  Removed old
 * not-necessary 24 bpp software stuff.
 * 
 * 71    3/25/98 8:07p John
 * Restructured software rendering into two modules; One for windowed
 * debug mode and one for DirectX fullscreen.   
 * 
 * 70    3/24/98 8:31a John
 * Added function to set gamma
 * 
 * 69    3/17/98 5:55p John
 * Added code to dump Glide frames.   Moved Allender's  "hack" code out of
 * Freespace.cpp into the proper place, graphics lib.
 * 
 * 68    3/12/98 5:36p John
 * Took out any unused shaders.  Made shader code take rgbc instead of
 * matrix and vector since noone used it like a matrix and it would have
 * been impossible to do in hardware.   Made Glide implement a basic
 * shader for online help.  
 * 
 * 67    3/10/98 4:18p John
 * Cleaned up graphics lib.  Took out most unused gr functions.   Made D3D
 * & Glide have popups and print screen.  Took out all >8bpp software
 * support.  Made Fred zbuffer.  Made zbuffer allocate dynamically to
 * support Fred.  Made zbuffering key off of functions rather than one
 * global variable.
 * 
 * 66    2/07/98 7:50p John
 * Added code so that we can use the old blending type of alphacolors if
 * we want to.  Made the stars use them.
 * 
 * 65    1/08/98 1:54p John
 * Added code to fix palette problems when Alt+Tabbing
 * 
 * 64    12/30/97 6:46p John
 * Added first rev of palette fade in out functions
 * 
 * 63    12/03/97 10:47a John
 * added functions to save/restore entire screens.
 * 
 * 62    12/02/97 3:59p John
 * Added first rev of thruster glow, along with variable levels of
 * translucency, which retquired some restructing of palman.
 * 
 * 61    11/20/97 9:51a John
 * added code to force screen to 16-bit even if rendering 8.
 * 
 * 60    11/03/97 10:08p Hoffoss
 * Changed gr_get_string_size to utilize an optional length specifier, if
 * you want to use non-null terminated strings.
 * 
 * 59    10/19/97 12:55p John
 * new code to lock / unlock surfaces for smooth directx integration.
 * 
 * 58    10/03/97 10:02a John
 * added better comments for lines.
 * 
 * 57    10/03/97 9:10a John
 * added better antialiased line drawer
 * 
 * 56    9/23/97 10:45a John
 * made so you can tell bitblt code to rle a bitmap by passing flag to
 * gr_set_bitmap
 * 
 * 55    9/07/97 10:01p Lawrance
 * add in support for animating mouse pointer
 * 
 * 54    8/04/97 4:47p John
 * added gr_aascaler.
 * 
 * 53    7/16/97 3:07p John
 * 
 * 52    7/10/97 2:06p John
 * added code to specify alphablending type for bitmaps.
 * 
 * 51    6/25/97 2:35p John
 * added some functions to use the windows font for Fred.
 * 
 * 50    6/17/97 7:04p John
 * added d3d support for gradients.
 * fixed some color bugs by adding screen signatures instead of watching
 * flags and palette changes.
 * 
 * 49    6/17/97 12:03p John
 * Moved color/alphacolor functions into their own module.  Made all color
 * functions be part of the low-level graphics drivers, not just the
 * grsoft.
 * 
 * 48    6/13/97 5:35p John
 * added some antialiased bitmaps and lines
 * 
 * 47    6/11/97 5:49p John
 * Changed palette code to only recalculate alphacolors when needed, not
 * when palette changes.
 * 
 * 46    6/11/97 4:11p John
 * addec function to get font height
 * 
 * 45    6/11/97 1:12p John
 * Started fixing all the text colors in the game.
 * 
 * 44    6/09/97 9:24a John
 * Changed the way fonts are set.
 * 
 * 43    6/06/97 4:41p John
 * Fixed alpha colors to be smoothly integrated into gr_set_color_fast
 * code.
 * 
 * 42    6/05/97 4:53p John
 * First rev of new antialiased font stuff.
 * 
 * 41    5/29/97 3:09p John
 * Took out debug menu.  
 * Made software scaler draw larger bitmaps.
 * Optimized Direct3D some.
 * 
 * 40    5/14/97 10:53a John
 * fixed some discrepencies between d3d and software palette setting.
 * 
 * 39    5/12/97 3:09p John
 * fixed a stupid macro bug.
 * 
 * 38    5/12/97 12:27p John
 * Restructured Graphics Library to add support for multiple renderers.
 * 
 * 37    4/28/97 4:46p John
 * 
 * 36    4/23/97 5:26p John
 * First rev of new debug console stuff.
 * 
 * 35    3/12/97 2:51p John
 * Added some test code for tmapper.  
 * 
 * 34    3/12/97 9:25a John
 * fixed a bug with zbuffering.  Reenabled it by default.
 * 
 * 33    3/04/97 3:36p John
 * took out old debug "h' key.   Made zbuffer flag bit bit field so you
 * can turn on/off each value.   Fixed a bug with turret rotation where
 * different handedness turrets wouldn't work.   Fixed a bug with two
 * large ships within each other's radius not rendering correctly.
 * 
 * 32    1/27/97 9:08a John
 * Added code to turn zbuffering on/off in call to g3_start_frame
 * 
 * 31    1/09/97 11:35a John
 * Added some 2d functions to get/put screen images.
 * 
 * 30    1/07/97 2:01p John
 * Fairly fast zbuffering for object sorting.
 * 
 * 29    1/06/97 2:44p John
 * Added in slow (but correct) zbuffering
 * 
 * 28    12/11/96 12:41p John
 * Added new code to draw 3d laser using 2d ellipses.
 * 
 * 27    12/10/96 10:37a John
 * Restructured texture mapper to remove some overhead from each scanline
 * setup.  This gave about a 30% improvement drawing trans01.pof, which is
 * a really complex model.  In the process, I cleaned up the scanline
 * functions and separated them into different modules for each pixel
 * depth.   
 * 
 * 26    11/21/96 11:21a John
 * Made gr_get_string_size handle multi line text.
 * Took out gr_get_multiline_string_size
 * 
 * 25    11/20/96 10:01a Hoffoss
 * A few minor improvements.
 * 
 * 24    11/18/96 4:35p Allender
 * new 16bpp gradient functions
 * 
 * 23    11/18/96 12:36p John
 * Added code to dump screen to a PCX file.
 * 
 * 22    11/18/96 11:40a John
 * Added faster gr_set_color method.
 * 
 * 21    11/15/96 3:34p Allender
 * added bpp variable to the shader structure
 * 
 * 20    11/13/96 6:47p John
 * Added gr_flip function.
 * 
 * 19    11/13/96 10:10a John
 * Increases MAX_WIDTH & HEIGHT for Jasen's massive 1600x1200 display.
 * 
 * 18    10/30/96 10:36a Lawrance
 * added gr_diamond function
 * 
 * 17    10/26/96 2:56p John
 * Got gradient code working.
 * 
 * 16    10/26/96 1:40p John
 * Added some now primitives to the 2d library and
 * cleaned up some old ones.
 *
 * $NoKeywords: $
 */

#ifndef _GRAPHICS_H
#define _GRAPHICS_H

/* ========================= pixel plotters =========================
In the 2d/texture mapper, bitmaps to be drawn will be passed by number.
The 2d function will call a bmpman function to get the bitmap into whatever
format it needs.  Then it will render.   The only pixels that will ever 
get drawn go thru the 2d/texture mapper libraries only.   This will make
supporting accelerators and psx easier.   Colors will always be set with
the color set functions.

gr_surface_flip()       switch onscreen, offscreen

gr_set_clip(x,y,w,h)    // sets the clipping region
gr_reset_clip(x,y,w,h)  // sets the clipping region
gr_set_color --? 8bpp, 15bpp?
gr_set_font(int fontnum)
// see GR_ALPHABLEND defines for values for alphablend_mode
// see GR_BITBLT_MODE defines for bitblt_mode.
// Alpha = scaler for intensity
gr_set_bitmap( int bitmap_num, int alphblend_mode, int bitblt_mode, float alpha )       
gr_set_shader( int value )  0=normal -256=darken, 256=brighten
gr_set_palette( ubyte * palette ) 

gr_clear()      // clears entire clipping region
gr_bitmap(x,y)
gr_bitmap_ex(x,y,w,h,sx,sy)
gr_rect(x,y,w,h)
gr_shade(x,y,w,h)
gr_string(x,y,char * text)
gr_line(x1,y1,x2,y2)

 
*/

#include "pstypes.h"
#include "tmapper.h"

// This is a structure used by the shader to keep track
// of the values you want to use in the shade primitive.
typedef struct shader {
        uint    screen_sig;                                     // current mode this is in
        float   r,g,b,c;                                                // factors and constant
        ubyte   lookup[256];
} shader;

#define AC_TYPE_NONE            0               // Not an alphacolor
#define AC_TYPE_HUD             1               // Doesn't change hue depending on background.  Used for HUD stuff.
#define AC_TYPE_BLEND   2               // Changes hue depending on background.  Used for stars, etc.

// NEVER REFERENCE THESE VALUES OUTSIDE OF THE GRAPHICS LIBRARY!!!
// If you need to get the rgb values of a "color" struct call
// gr_get_colors after calling gr_set_colors_fast.
typedef struct color {
        uint            screen_sig;
        ubyte           red;
        ubyte           green;
        ubyte           blue;
        ubyte           alpha;
        ubyte           ac_type;                                                        // The type of alphacolor.  See AC_TYPE_??? defines
        int             is_alphacolor;
        ubyte           raw8;
        int             alphacolor;
        int             magic;          
} color;

#define GR_ALPHABLEND_NONE                      0               // no blending
#define GR_ALPHABLEND_FILTER            1               // 50/50 mix of foreground, background, using intensity as alpha

#define GR_BITBLT_MODE_NORMAL           0               // Normal bitblting
#define GR_BITBLT_MODE_RLE                      1               // RLE would be faster

// fog modes
#define GR_FOGMODE_NONE                         0               // set this to turn off fog
#define GR_FOGMODE_FOG                          1               // linear fog

typedef struct screen {
        uint    signature;                      // changes when mode or palette or width or height changes
        int     max_w, max_h;           // Width and height
        int     res;                                    // GR_640 or GR_1024
        int     mode;                                   // What mode gr_init was called with.
        float   aspect;                         // Aspect ratio
        int     rowsize;                                // What you need to add to go to next row (includes bytes_per_pixel)
        int     bits_per_pixel; // How many bits per pixel it is. (7,8,15,16,24,32)
        int     bytes_per_pixel;        // How many bytes per pixel (1,2,3,4)
        int     offset_x, offset_y;             // The offsets into the screen
        int     clip_width, clip_height;

        float fog_near, fog_far;

        // the clip_l,r,t,b are used internally.  left and top are
        // actually always 0, but it's nice to have the code work with
        // arbitrary clipping regions.
        int             clip_left, clip_right, clip_top, clip_bottom;   

        int             current_alphablend_mode;                // See GR_ALPHABLEND defines above
        int             current_bitblt_mode;                            // See GR_BITBLT_MODE defines above
        int             current_fog_mode;                                       // See GR_FOGMODE_* defines above
        int             current_bitmap;
        int             current_bitmap_sx;                              // bitmap x section
        int             current_bitmap_sy;                              // bitmap y section
        color           current_color;
        color           current_fog_color;                              // current fog color
        color           current_clear_color;                            // current clear color
        shader  current_shader;
        float           current_alpha;
        void            *offscreen_buffer;                              // NEVER ACCESS!  This+rowsize*y = screen offset
        void            *offscreen_buffer_base;                 // Pointer to lowest address of offscreen buffer

        //switch onscreen, offscreen
        void (*gf_flip)();
        void (*gf_flip_window)(uint _hdc, int x, int y, int w, int h );

        // Sets the current palette
        void (*gf_set_palette)(ubyte * new_pal, int restrict_alphacolor = 0);

        // Fade the screen in/out
        void (*gf_fade_in)(int instantaneous);
        void (*gf_fade_out)(int instantaneous);

        // Flash the screen
        void (*gf_flash)( int r, int g, int b );

        // sets the clipping region
        void (*gf_set_clip)(int x, int y, int w, int h);

        // resets the clipping region to entire screen
        void (*gf_reset_clip)();

        void (*gf_set_color)( int r, int g, int b );
        void (*gf_get_color)( int * r, int * g, int * b );
        void (*gf_init_color)( color * dst, int r, int g, int b );

        void (*gf_init_alphacolor)( color * dst, int r, int g, int b, int alpha, int type=AC_TYPE_HUD );
        void (*gf_set_color_fast)( color * dst );

        void (*gf_set_font)(int fontnum);

        // Sets the current bitmap
        void (*gf_set_bitmap)( int bitmap_num, int alphablend=GR_ALPHABLEND_NONE, int bitbltmode=GR_BITBLT_MODE_NORMAL, float alpha=1.0f, int sx = -1, int sy = -1 );

        // Call this to create a shader.   
        // This function takes a while, so don't call it once a frame!
        // r,g,b, and c should be between -1.0 and 1.0f

        // The matrix is used as follows:
        // Dest(r) = Src(r)*r + Src(g)*r + Src(b)*r + c;
        // Dest(g) = Src(r)*g + Src(g)*g + Src(b)*g + c;
        // Dest(b) = Src(r)*b + Src(g)*b + Src(b)*b + c;
        // For instance, to convert to greyscale, use
        // .3 .3 .3  0
        // To turn everything green, use:
        //  0 .3  0  0
        void (*gf_create_shader)(shader * shade, float r, float g, float b, float c );

        // Initialize the "shader" by calling gr_create_shader()
        // Passing a NULL makes a shader that turns everything black.
        void (*gf_set_shader)( shader * shade );

        // clears entire clipping region to current color
        void (*gf_clear)();

        // void (*gf_bitmap)(int x,int y);
        // void (*gf_bitmap_ex)(int x,int y,int w,int h,int sx,int sy);

        void (*gf_aabitmap)(int x, int y);
        void (*gf_aabitmap_ex)(int x, int y, int w, int h, int sx, int sy);

        void (*gf_rect)(int x, int y, int w, int h);
        void (*gf_shade)(int x, int y, int w, int h);
        void (*gf_string)(int x, int y, char * text);

        // Draw a gradient line... x1,y1 is bright, x2,y2 is transparent.
        void (*gf_gradient)(int x1, int y1, int x2, int y2);
 
        void (*gf_circle)(int x, int y, int r);

        // Integer line. Used to draw a fast but pixely line.  
        void (*gf_line)(int x1, int y1, int x2, int y2);

        // Draws an antialiased line is the current color is an 
        // alphacolor, otherwise just draws a fast line.  This
        // gets called internally by g3_draw_line.   This assumes
        // the vertex's are already clipped, so call g3_draw_line
        // not this if you have two 3d points.
        void (*gf_aaline)(vertex *v1, vertex *v2);

        void (*gf_pixel)( int x, int y );

        // Scales current bitmap between va and vb with clipping
        void (*gf_scaler)(vertex *va, vertex *vb );

        // Scales current bitmap between va and vb with clipping, draws an aabitmap
        void (*gf_aascaler)(vertex *va, vertex *vb );

        // Texture maps the current bitmap.  See TMAP_FLAG_?? defines for flag values
        void (*gf_tmapper)(int nv, vertex *verts[], uint flags );

        // dumps the current screen to a file
        void (*gf_print_screen)(char * filename);

        // Call once before rendering anything.
        void (*gf_start_frame)();

        // Call after rendering is over.
        void (*gf_stop_frame)();

        // Retrieves the zbuffer mode.
        int (*gf_zbuffer_get)();

        // Sets mode.  Returns previous mode.
        int (*gf_zbuffer_set)(int mode);

        // Clears the zbuffer.  If use_zbuffer is FALSE, then zbuffering mode is ignored and zbuffer is always off.
        void (*gf_zbuffer_clear)(int use_zbuffer);
        
        // Saves screen. Returns an id you pass to restore and free.
        int (*gf_save_screen)();
        
        // Resets clip region and copies entire saved screen to the screen.
        void (*gf_restore_screen)(int id);

        // Frees up a saved screen.
        void (*gf_free_screen)(int id);

        // CODE FOR DUMPING FRAMES TO A FILE
        // Begin frame dumping
        void (*gf_dump_frame_start)( int first_frame_number, int nframes_between_dumps );

        // Dump the current frame to file
        void (*gf_dump_frame)();

        // Dump the current frame to file
        void (*gf_dump_frame_stop)();

        // Sets the gamma
        void (*gf_set_gamma)(float gamma);

        // Lock/unlock the screen
        // Returns non-zero if sucessful (memory pointer)
        uint (*gf_lock)();
        void (*gf_unlock)();

        // grab a region of the screen. assumes data is large enough
        void (*gf_get_region)(int front, int w, int h, ubyte *data);

        // set fog attributes
        void (*gf_fog_set)(int fog_mode, int r, int g, int b, float fog_near = -1.0f, float fog_far = -1.0f);   

        // get the current pixel color in the framebuffer 
        void (*gf_get_pixel)(int x, int y, int *r, int *g, int *b);

        // poly culling
        void (*gf_set_cull)(int cull);

        // cross fade
        void (*gf_cross_fade)(int bmap1, int bmap2, int x1, int y1, int x2, int y2, float pct);

        // filtering
        void (*gf_filter_set)(int filter);

        // set a texture into cache. for sectioned bitmaps, pass in sx and sy to set that particular section of the bitmap
        int (*gf_tcache_set)(int bitmap_id, int bitmap_type, float *u_scale, float *v_scale, int fail_on_full = 0, int sx = -1, int sy = -1, int force = 0);    

        // set the color to be used when clearing the background
        void (*gf_set_clear_color)(int r, int g, int b);
} screen;

// cpu types
extern int Gr_amd3d;
extern int Gr_katmai;
extern int Gr_cpu;      
extern int Gr_mmx;

// handy macro
#define GR_MAYBE_CLEAR_RES(bmap)                do  { int bmw = -1; int bmh = -1; if(bmap != -1){ bm_get_info( bmap, &bmw, &bmh); if((bmw != gr_screen.max_w) || (bmh != gr_screen.max_h)){gr_clear();} } else {gr_clear();} } while(0);

//Window's interface to set up graphics:
//--------------------------------------
// Call this at application startup

#define GR_SOFTWARE                                     (100)           // Software renderer using standard Win32 functions in a window.
#define GR_DIRECTDRAW                           (101)           // Software renderer using DirectDraw fullscreen.
#define GR_DIRECT3D                                     (102)           // Use Direct3d hardware renderer
#define GR_GLIDE                                                (103)           // Use Glide hardware renderer
#define GR_OPENGL                                               (104)           // Use OpenGl hardware renderer

// resolution constants   - always keep resolutions in ascending order and starting from 0  
#define GR_NUM_RESOLUTIONS                      2
#define GR_640                                                  0               // 640 x 480
#define GR_1024                                         1               // 1024 x 768

extern int gr_init(int res, int mode, int depth = 16, int fred_x = -1, int fred_y = -1 );

// Call this when your app ends.
extern void gr_close();

extern screen gr_screen;

#define GR_ZBUFF_NONE   0
#define GR_ZBUFF_WRITE  (1<<0)
#define GR_ZBUFF_READ   (1<<1)
#define GR_ZBUFF_FULL   (GR_ZBUFF_WRITE|GR_ZBUFF_READ)

// Returns -1 if couldn't init font, otherwise returns the
// font id number.  If you call this twice with the same typeface,
// it will return the same font number both times.  This font is
// then set to be the current font, and default font if none is 
// yet specified.
int gr_init_font( char * typeface );

// Does formatted printing.  This calls gr_string after formatting,
// so if you don't need to format the string, then call gr_string
// directly.
extern void _cdecl gr_printf( int x, int y, char * format, ... );

// Returns the size of the string in pixels in w and h
extern void gr_get_string_size( int *w, int *h, char * text, int len = 9999 );

// Returns the height of the current font
extern int gr_get_font_height();

extern void gr_set_palette(char *name, ubyte *palette, int restrict_to_128 = 0);

// These two functions use a Windows mono font.  Only for use
// in the editor, please.
void gr_get_string_size_win(int *w, int *h, char *text);
void gr_string_win(int x, int y, char *s );

// set the mouse pointer to a specific bitmap, used for animating cursors
#define GR_CURSOR_LOCK          1
#define GR_CURSOR_UNLOCK        2
void gr_set_cursor_bitmap(int n, int lock = 0);
int gr_get_cursor_bitmap();
extern int Web_cursor_bitmap;

// Called by OS when application gets/looses focus
extern void gr_activate(int active);

#define GR_CALL(x)                      (*x)

// These macros make the function indirection look like the
// old Descent-style gr_xxx calls.

#define gr_print_screen         GR_CALL(gr_screen.gf_print_screen)

#define gr_flip                         GR_CALL(gr_screen.gf_flip)
#define gr_flip_window          GR_CALL(gr_screen.gf_flip_window)

#define gr_set_clip                     GR_CALL(gr_screen.gf_set_clip)
#define gr_reset_clip           GR_CALL(gr_screen.gf_reset_clip)
#define gr_set_font                     GR_CALL(gr_screen.gf_set_font)

#define gr_init_color           GR_CALL(gr_screen.gf_init_color)
#define gr_init_alphacolor      GR_CALL(gr_screen.gf_init_alphacolor)
#define gr_set_color                    GR_CALL(gr_screen.gf_set_color)
#define gr_get_color                    GR_CALL(gr_screen.gf_get_color)
#define gr_set_color_fast       GR_CALL(gr_screen.gf_set_color_fast)

#define gr_set_bitmap           GR_CALL(gr_screen.gf_set_bitmap)

#define gr_create_shader        GR_CALL(gr_screen.gf_create_shader)
#define gr_set_shader           GR_CALL(gr_screen.gf_set_shader)
#define gr_clear                                GR_CALL(gr_screen.gf_clear)
// #define gr_bitmap                            GR_CALL(gr_screen.gf_bitmap)
// #define gr_bitmap_ex                 GR_CALL(gr_screen.gf_bitmap_ex)
#define gr_aabitmap                     GR_CALL(gr_screen.gf_aabitmap)
#define gr_aabitmap_ex          GR_CALL(gr_screen.gf_aabitmap_ex)
#define gr_rect                         GR_CALL(gr_screen.gf_rect)
#define gr_shade                                GR_CALL(gr_screen.gf_shade)
#define gr_string                               GR_CALL(gr_screen.gf_string)

#define gr_circle                               GR_CALL(gr_screen.gf_circle)

#define gr_line                         GR_CALL(gr_screen.gf_line)
#define gr_aaline                               GR_CALL(gr_screen.gf_aaline)
#define gr_pixel                                GR_CALL(gr_screen.gf_pixel)
#define gr_scaler                               GR_CALL(gr_screen.gf_scaler)
#define gr_aascaler                     GR_CALL(gr_screen.gf_aascaler)
#define gr_tmapper                      GR_CALL(gr_screen.gf_tmapper)

#define gr_gradient                     GR_CALL(gr_screen.gf_gradient)


#define gr_fade_in                      GR_CALL(gr_screen.gf_fade_in)
#define gr_fade_out                     GR_CALL(gr_screen.gf_fade_out)
#define gr_flash                                GR_CALL(gr_screen.gf_flash)

#define gr_zbuffer_get          GR_CALL(gr_screen.gf_zbuffer_get)
#define gr_zbuffer_set          GR_CALL(gr_screen.gf_zbuffer_set)
#define gr_zbuffer_clear        GR_CALL(gr_screen.gf_zbuffer_clear)

#define gr_save_screen          GR_CALL(gr_screen.gf_save_screen)
#define gr_restore_screen       GR_CALL(gr_screen.gf_restore_screen)
#define gr_free_screen          GR_CALL(gr_screen.gf_free_screen)

#define gr_dump_frame_start     GR_CALL(gr_screen.gf_dump_frame_start)
#define gr_dump_frame_stop              GR_CALL(gr_screen.gf_dump_frame_stop)
#define gr_dump_frame                   GR_CALL(gr_screen.gf_dump_frame)

#define gr_set_gamma                    GR_CALL(gr_screen.gf_set_gamma)

#define gr_lock                         GR_CALL(gr_screen.gf_lock)
#define gr_unlock                               GR_CALL(gr_screen.gf_unlock)

#define gr_get_region           GR_CALL(gr_screen.gf_get_region)

#define gr_fog_set                      GR_CALL(gr_screen.gf_fog_set)

#define gr_get_pixel                    GR_CALL(gr_screen.gf_get_pixel)

#define gr_set_cull                     GR_CALL(gr_screen.gf_set_cull)

#define gr_cross_fade           GR_CALL(gr_screen.gf_cross_fade)

#define gr_filter_set           GR_CALL(gr_screen.gf_filter_set)

#define gr_tcache_set           GR_CALL(gr_screen.gf_tcache_set)

#define gr_set_clear_color      GR_CALL(gr_screen.gf_set_clear_color)

// new bitmap functions
extern int Gr_bitmap_poly;
void gr_bitmap(int x, int y);
void gr_bitmap_ex(int x, int y, int w, int h, int sx, int sy);

// special function for drawing polylines. this function is specifically intended for
// polylines where each section is no more than 90 degrees away from a previous section.
// Moreover, it is _really_ intended for use with 45 degree angles. 
void gr_pline_special(vector **pts, int num_pts, int thickness);

#endif