OpenEuphoria

Allegro Wrapper Concerns

• Posted by Icy_Viking Oct 09, 2022
• 669 views

Hi all,

As I am starting on wrapping an allegro wrapper using the new ffi.e, I have come across a few issues that are sorta bothersome, but not a huge deal in the grand scheme of things. Though I was wondering if anyone had any thoughts on this. I want to keep the allegro as close to the C source as possible. For example color.h would be color.e and contain the functions found in color.h, but of course wrapped as Euphoria functions.

I'll show some code to show what I mean.

Main Allegro.e

--Allegro.e 
--Basically converted into Euphoria from C code (base.h) 
 
include std/ffi.e 
include std/math.e 
include std/machine.e 
 
public constant ALLEGRO_VERSION = 5, 
			    ALLEGRO_SUB_VERSION = 2, 
			    ALLEGRO_WIP_VERSION = 6 
			     
public constant ALLEGRO_RELEASE_NUMBER = 1 
 
public constant ALLEGRO_UNSTABLE_BIT = -2147483648 
 
public constant ALLEGRO_PI = 3.14159265358979323846 
 
public constant ALLEGRO_VERSION_INT = or_all({ shift_bits(ALLEGRO_VERSION,-24),  
	shift_bits(ALLEGRO_SUB_VERSION,-16), shift_bits(ALLEGRO_WIP_VERSION, -8), 
	ALLEGRO_RELEASE_NUMBER,ALLEGRO_UNSTABLE_BIT}) 
	 
include color.e 
	 
export constant all = open_dll("allegro-5.2.dll"), 
	xal_get_allegro_version = define_c_func(all,"+al_get_allegro_version",{},C_UINT), 
	xal_run_main = define_c_func(all,"+al_run_main",{C_INT,C_POINTER,C_INT,C_INT,C_POINTER},C_INT), 
	--color functions 
	xal_map_rgb = define_c_func(all,"+al_map_rgb",{C_UCHAR,C_UCHAR,C_UCHAR},ALLEGRO_COLOR), 
	xal_map_rgba = define_c_func(all,"+al_map_rgba",{C_UCHAR,C_UCHAR,C_UCHAR,C_UCHAR},ALLEGRO_COLOR), 
	xal_map_rgb_f = define_c_func(all,"+al_map_rgb_f",{C_FLOAT,C_FLOAT,C_FLOAT},ALLEGRO_COLOR), 
	xal_map_rgba_f = define_c_func(all,"+al_map_rgba_f",{C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT},ALLEGRO_COLOR), 
	xal_premul_rgba = define_c_func(all,"+al_premul_rgba",{C_UCHAR,C_UCHAR,C_UCHAR,C_UCHAR},ALLEGRO_COLOR), 
	xal_premul_rgba_f = define_c_func(all,"+al_premul_rgba_f",{C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT},ALLEGRO_COLOR), 
$ 
 
public function al_get_allegro_version() 
	return c_func(xal_get_allegro_version,{}) 
end function 
 
public function al_run_main(atom argc,sequence argv,atom x,atom x2,sequence char) 
	return c_func(xal_run_main,{argc,argv,x,x2,char}) 
end function 
 
--Color 
 
public function al_map_rgb(integer r,integer g,integer b) 
	return c_func(xal_map_rgb,{r,g,b}) 
end function 
 
public function al_map_rgba(integer r,integer g,integer b,integer a) 
	return c_func(xal_map_rgba,{r,g,b,a}) 
end function 
 
public function al_map_rgb_f(atom r,atom g,atom b) 
	return c_func(xal_map_rgb_f,{r,g,b}) 
end function 
 
public function al_map_rgba_f(atom r,atom g,atom b,atom a) 
	return c_func(xal_map_rgba_f,{r,g,b,a}) 
end function 
 
public function al_premul_rgba(integer r,integer g,integer b,integer a) 
	return c_func(xal_premul_rgba,{r,g,b,a}) 
end function 
 
public function al_premul_rgba_f(atom r,atom g,atom b,atom a) 
	return c_func(xal_premul_rgba_f,{r,g,b,a}) 
end function 

Color.e

include std/ffi.e 
 
public constant ALLEGRO_COLOR = define_c_type({ 
	C_FLOAT, --r 
	C_FLOAT, --g 
	C_FLOAT, --b 
	C_FLOAT --a 
}) 
 
public enum type ALLEGRO_PIXEL_FORMAT 
	ALLEGRO_PIXEL_FORMAT_ANY                   = 0, 
   
	ALLEGRO_PIXEL_FORMAT_ANY_NO_ALPHA          = 1, 
   
	ALLEGRO_PIXEL_FORMAT_ANY_WITH_ALPHA        = 2, 
   
	ALLEGRO_PIXEL_FORMAT_ANY_15_NO_ALPHA       = 3, 
   
	ALLEGRO_PIXEL_FORMAT_ANY_16_NO_ALPHA       = 4, 
   
	ALLEGRO_PIXEL_FORMAT_ANY_16_WITH_ALPHA     = 5, 
   
	 ALLEGRO_PIXEL_FORMAT_ANY_24_NO_ALPHA       = 6, 
   
	 ALLEGRO_PIXEL_FORMAT_ANY_32_NO_ALPHA       = 7, 
   
	  ALLEGRO_PIXEL_FORMAT_ANY_32_WITH_ALPHA     = 8, 
   
	   ALLEGRO_PIXEL_FORMAT_ARGB_8888             = 9, 
   
	  ALLEGRO_PIXEL_FORMAT_RGBA_8888             = 10, 
   
	  ALLEGRO_PIXEL_FORMAT_ARGB_4444             = 11, 
   
	   ALLEGRO_PIXEL_FORMAT_RGB_888               = 12, --/* 24 bit format */ 
   
	    ALLEGRO_PIXEL_FORMAT_RGB_565               = 13, 
  
	     ALLEGRO_PIXEL_FORMAT_RGB_555               = 14, 
   
	     ALLEGRO_PIXEL_FORMAT_RGBA_5551             = 15, 
   
	      ALLEGRO_PIXEL_FORMAT_ARGB_1555             = 16, 
   
	        ALLEGRO_PIXEL_FORMAT_ABGR_8888             = 17, 
   
	         ALLEGRO_PIXEL_FORMAT_XBGR_8888             = 18, 
   
	            ALLEGRO_PIXEL_FORMAT_BGR_888               = 19, --/* 24 bit format */ 
   
	          ALLEGRO_PIXEL_FORMAT_BGR_565               = 20, 
   
	             ALLEGRO_PIXEL_FORMAT_BGR_555               = 21, 
   
	           ALLEGRO_PIXEL_FORMAT_RGBX_8888             = 22, 
   
	             ALLEGRO_PIXEL_FORMAT_XRGB_8888             = 23, 
   
	              ALLEGRO_PIXEL_FORMAT_ABGR_F32              = 24, 
   
	               ALLEGRO_PIXEL_FORMAT_ABGR_8888_LE          = 25, 
   
	                 ALLEGRO_PIXEL_FORMAT_RGBA_4444             = 26, 
   
	                 ALLEGRO_PIXEL_FORMAT_SINGLE_CHANNEL_8      = 27, 
   
	                  ALLEGRO_PIXEL_FORMAT_COMPRESSED_RGBA_DXT1  = 28, 
   
	                  ALLEGRO_PIXEL_FORMAT_COMPRESSED_RGBA_DXT3  = 29, 
   
	                   ALLEGRO_PIXEL_FORMAT_COMPRESSED_RGBA_DXT5  = 30, 
   
	                   ALLEGRO_NUM_PIXEL_FORMATS 
end type 
 

AS you can see, I can keep the flags in the color.e, but ideally I would like to have the functions in there too. When I tried to run it, I got an error saying the 'all' variable could not be found. So I put the color functions in the main allegro.e and it worked. If there's any tips or tricks I can use, I'd sure like to know them.