OpenEuphoria

Simple2D Wrapper Help

• Posted by Icy_Viking Apr 18, 2023
• 586 views

Hello all,

Okay once again I'm having a issue with callbacks. After messing around with the Simple2D source code for a couple of hours, I was able to build and export the functions into a DLL. I made a quick test and it works. The example shows a triangle being displayed, however the triangle function is a callback within the create_window() function. I've listed some snippets of code to help. Let me know if more code is needed. If needed I can also put what I have so far into a .zip file.

Note: I added declspec(dllexport) to get the functions exported into a DLL while building the simple2D library.

Note 2: Simple2D relies heavily on the SDL2 library and its add-ons, good thing I already made a SDL2 wrapper and wrappers for those add-ons, lol. Oh also, Simple2D was built using 64-bit compiler, so I have the 64-bit SDL2 DLL and of course the 64-bit version of Euphoria. It won't work on 32-bit version of Euphoria.

https://github.com/simple2d/simple2d/blob/main/include/simple2d.h

//From simple2D.h 
//Callback functions 
typedef void (*S2D_Update)(); 
typedef void (*S2D_Render)(); 
typedef void (*S2D_On_Key)(S2D_Event e); 
typedef void (*S2D_On_Mouse)(S2D_Event e); 
typedef void (*S2D_On_Controller)(S2D_Event e); 
 
__declspec(dllexport) S2D_Window *S2D_CreateWindow( 
  const char *title, int width, int height, S2D_Update, S2D_Render, int flags 
); 
//I slightly modified the include file by making it so the functions would be exported to a DLL 
//S2D_Update and S2D_Render are callbacks. 

Wrapper code

include std/ffi.e 
include SDL.e  
atom simple = 0 
 
ifdef WINDOWS then 
	simple = open_dll("simple2d.dll") 
	elsifdef LINUX or FREEBSD then 
	simple = open_dll("simple2d.so") 
end ifdef 
 
export constant xS2D_Init = define_c_func(simple,"+S2D_Init",{},C_BOOL) 
 
public function S2D_Init() 
	return c_func(xS2D_Init,{}) 
end function 
 
export constant xS2D_CreateWindow = define_c_func(simple,"+S2D_CreateWindow",{C_STRING,C_INT,C_INT,C_POINTER,C_POINTER,C_INT},C_POINTER) 
 
public function S2D_CreateWindow(sequence title,atom width,atom height,object update,object render,atom flags) 
	return c_func(xS2D_CreateWindow,{title,width,height,update,render,flags}) 
       --callback should be implemented where update and render but I'm at a lost at how to wrap them 
end function 
 
export constant xS2D_Show = define_c_func(simple,"+S2D_Show",{C_POINTER},C_INT) 
 
public function S2D_Show(atom win) 
	return c_func(xS2D_Show,{win}) 
end function 
 
export constant xS2D_DrawTriangle = define_c_proc(simple,"+S2D_DrawTriangle",{C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT,C_FLOAT}) 
 
public procedure S2D_DrawTriangle(atom x1,atom y1,atom r1,atom g1,atom b1,atom a1,atom x2,atom y2,atom r2,atom g2,atom b2,atom a2,atom x3,atom y3,atom r3,atom g3,atom b3,atom a3) 
	c_proc(xS2D_DrawTriangle,{x1,y1,r1,g1,b1,a1,x2,y2,r2,g2,b2,a2,x3,y3,r3,g3,b3,a3}) 
end procedure 
 
export constant xS2D_Quit = define_c_proc(simple,"+S2D_Quit",{}) 
 
public procedure S2D_Quit() 
	c_proc(xS2D_Quit,{}) 
end procedure 

Simple test

include std/ffi.e --for NULL 
 
include simple2d.e 
 
atom x = S2D_Init() 
 
if x = -1 then 
	puts(1,"Failed to init Simple2D!\n") 
	abort(0) 
end if 
 
procedure triangle() 
	S2D_DrawTriangle(320,50,1,0,0,1, 
					 540,430,0,1,0,1, 
					 100,430,0,0,1,1) 
end procedure 
 
atom win = S2D_CreateWindow("Triangle Test",640,480,NULL,NULL,0) 
--triangle() should be where the second "NULL" is. This simple test does work except for the triangle showing, a basic window shows up 
S2D_Show(win) 
 
S2D_Quit()