Subversion Repositories Kolibri OS

; simple gl like driver for TinyGL and KolibriOS - porting iadn

struct TinyGLContext

	gl_context dd ?

	xsize dd ? ;+4

	ysize dd ? ;+8

	d_x dd ? ;+12

	d_y dd ? ;+16

	x dd ? ;+20

	y dd ? ;+24

ends

;KOSGLContext kosglCreateContext(KOSGLContext shareList, int flags)

;{

;  TinyGLContext *ctx;

;  if (shareList != NULL) {

;    gl_fatal_error("No sharing available in TinyGL");

;  }

;    ctx=gl_malloc(sizeof(TinyGLContext));

;  if (!ctx)

;      return NULL;

;  ctx->gl_context=NULL;

;  return (KOSGLContext) ctx;

;}

;void kosglDestroyContext( KOSGLContext ctx1 )

;{

;  TinyGLContext *ctx = (TinyGLContext *) ctx1;

;  if (ctx->gl_context != NULL) {

;    glClose();

;  }

;  gl_free(ctx);

;}

; resize the glx viewport : we try to use the xsize and ysize

; given. We return the effective size which is guaranted to be smaller

align 4

proc gl_resize_viewport uses ebx ecx edx edi esi, context:dword, xsize_ptr:dword, ysize_ptr:dword

	xor eax,eax

	mov ecx,[xsize_ptr] ; ecx = &xsize

	mov edi,[ecx]       ; edi =  xsize

	mov esi,[ysize_ptr] ; esi = &ysize

	mov esi,[esi]       ; esi =  ysize

	; we ensure that xsize and ysize are multiples of 2 for the zbuffer.

	; TODO: find a better solution

	and edi, not 3

	and esi, not 3

	cmp edi,0

	jne @f

	cmp esi,0

	jne @f

		mov eax,-1

		jmp .end_f

	@@:

	mov [ecx],edi

	dec dword[ecx]

	mov ecx,[ysize_ptr]

	mov [ecx],esi

	dec dword[ecx]

	mov ebx,[context]

	mov edx,[ebx+GLContext.opaque] ; edx = (TinyGLContext *)context.opaque

	mov [edx+4],edi

	mov [edx+12],edi ;d_x = xsize

	mov [edx+8],esi

	mov [edx+16],esi ;d_y = ysize

	; resize the Z buffer

	stdcall ZB_resize, dword[ebx+GLContext.zb],0,edi,esi

	.end_f:

	ret

endp

; we assume here that drawable is a window

align 4

proc kosglMakeCurrent uses ebx ecx, win_x0:dword, win_y0:dword, win_x:dword, win_y:dword, ctx1:dword

	mov ebx,[ctx1]

	cmp dword[ebx],0 ;if (ctx.gl_context == NULL)

	jne .end_f

		; create the TinyGL context

		mov ecx,[win_x0]

		mov [ebx+20],ecx ;ctx.x = win_x0

		mov ecx,[win_y0]

		mov [ebx+24],ecx ;ctx.y = win_y0

		mov ecx,[win_x]

		mov [ebx+12],ecx ;ctx.d_x = win_x

		mov ecx,[win_y]

		mov [ebx+16],ecx ;ctx.d_y = win_y

		; currently, we only support 16 bit rendering

		xor eax,eax

		stdcall ZB_open, dword[win_x], dword[win_y], dword ZB_MODE_RGB24, eax,eax,eax,eax ;NULL,NULL,NULL

		or eax,eax

		jnz @f

			stdcall dbg_print,sz_kosglMakeCurrent,err_0

			xor eax,eax

			jmp .err_f

		@@:

		; initialisation of the TinyGL interpreter

		stdcall glInit, eax

		call gl_get_context

		mov [ebx],eax ;ctx.gl_context = eax

		mov [eax+GLContext.opaque],ebx ;ctx.gl_context.opaque = ctx

		mov dword[eax+GLContext.gl_resize_viewport],gl_resize_viewport

		; set the viewport : we force a call to gl_resize_viewport

		dec dword[eax+GLContext.viewport+offs_vpor_xsize]

		dec dword[eax+GLContext.viewport+offs_vpor_ysize]

		stdcall glViewport, 0, 0, [win_x], [win_y]

	.end_f:

	xor eax,eax

	inc eax

	.err_f:

	ret

endp

align 4

proc kosglSwapBuffers uses eax ebx ecx edx esi

	; retrieve the current TinyGLContext

	call gl_get_context

	mov ebx,[eax+GLContext.zb]

	mov ebx,[ebx+offs_zbuf_pbuf]

	mov esi,[eax+GLContext.opaque] ;esi = &context.opaque

	mov eax,7

	mov ecx,[esi+12] ;d_x

	shl ecx,16

	mov cx,[esi+16] ;d_y

	mov edx,[esi+20] ;x

	shl edx,16

	mov dx,[esi+24] ;y

	int 0x40

	ret

endp