[KERNEL] Add sysfn 39.3 - copy rect of background image to buffer.

Previously was only 39.2 that reads one pixel from background image.
(39.2 is shomehow useless due to big context switching overhead if you trying to read some area of pixels using 39.2)

git-svn-id: svn://kolibrios.org@9458 a494cfbc-eb01-0410-851d-a64ba20cac60

kernel/trunk/docs/sysfuncr.txt

@@ -2023,6 +2023,24 @@ path    db  'HD0/1',0
   * Есть парная функция установки точки на фоновом изображении -
     подфункция 2 функции 15.
 
+---------------------- Константы для регистров: ----------------------
+  eax - SF_BACKGROUND_GET_RECT (39)
+======================================================================
+== Функция 39, подфункция 3 - получить прямоугольную область фона    =
+======================================================================
+Параметры:
+  * eax = 39 - номер функции
+  * ebx = 3 - номер подфункции
+  * ecx = [x]*65536 + [y]
+  * edx = [width]*65536 + [height]
+  * esi = адрес буфера
+Возвращаемое значение:
+  * eax = 0 - успех
+  * eax = -1 - ошибка
+Замечания:
+  * Функция копирует указанную прямоугольную область в буфер в формате
+    0x00RRGGBB
+
 ---------------------- Константы для регистров: ----------------------
   eax - SF_BACKGROUND_GET (39)
 ======================================================================

kernel/trunk/docs/sysfuncs.txt

@@ -2004,6 +2004,24 @@ Remarks:
   * There is a pair function to set pixel on the background image -
     subfunction 2 of function 15.
 
+---------------------- Constants for registers: ----------------------
+  eax - SF_BACKGROUND_GET_RECT (39)
+======================================================================
+== Function 39, subfunction 3 - get rect from the background image.  =
+======================================================================
+Parameters:
+  * eax = 39 - function number
+  * ebx = 3 - subfunction number
+  * ecx = [x]*65536 + [y]
+  * edx = [width]*65536 + [height]
+  * esi = buffer address
+Returned value:
+  * eax = 0 - success
+  * eax = -1 - error
+Remarks:
+  * Function copies specified rectangle of background image to buffer
+    in 0x00RRGGBB format
+
 ---------------------- Constants for registers: ----------------------
   eax - SF_BACKGROUND_GET (39)
 ======================================================================

kernel/trunk/kernel.asm

@@ -3053,10 +3053,10 @@ force_redraw_background:
         ret
 ;------------------------------------------------------------------------------
 align 4
-sys_getbackground:
+sys_getbackground: ; sysfn 39
-;    cmp   eax,1                                  ; SIZE
         dec     ebx
-        jnz     nogb1
+        jnz     .nogb1
+        ; sysfn 39.1:
         mov     eax, [BgrDataWidth]
         shl     eax, 16
         mov     ax, word [BgrDataHeight]
@@ -3064,17 +3064,15 @@ sys_getbackground:
         ret
 ;------------------------------------------------------------------------------
 align 4
-nogb1:
+.nogb1:
-;    cmp   eax,2                                  ; PIXEL
         dec     ebx
-        jnz     nogb2
+        jnz     .nogb2
-
+        ; sysfn 39.2:
         mov     eax, [img_background]
         test    ecx, ecx
         jz      @f
         cmp     eax, static_background_data
         jz      .ret
-;--------------------------------------
 align 4
 @@:
         mov     ebx, [mem_BACKGROUND]
@@ -3088,22 +3086,109 @@ align 4
 
         and     eax, 0xFFFFFF
         mov     [esp+32], eax
-;--------------------------------------
 align 4
 .ret:
         ret
 ;------------------------------------------------------------------------------
 align 4
-nogb2:
+        .x      dd ?
+        .y      dd ?
+        .w      dd ?
+        .h      dd ?
+        .subrect_startptr dd ?
+        .subrect_bytes dd ?
+align 4
+.nogb2:
+        dec     ebx
+        jnz     .nogb3
+        ; sysfn 39.3 read background subrect to buffer
+        ; ecx - <x, y>
+        ; edx - <w, h>
+        ; esi - buffer of 0x00RRGGBB
+        mov     eax, [img_background]
+        cmp     eax, static_background_data
+        jz      .ret_39_3
+align 4
+@@:
+        movzx   eax, cx ; store y in eax
+        mov     [.y], eax
 
-;    cmp   eax,4                                  ; TILED / STRETCHED
+        shr     ecx, 16 ; ecx = x
+        mov     [.x], ecx
+
+        imul    eax, [BgrDataWidth]
+        add     eax, ecx
+        imul    eax, 3
+        mov     [.subrect_startptr], eax
+
+        movzx   eax, dx ; store h in eax
+        mov     [.h], eax
+
+        shr     edx, 16 ; edx = w
+        mov     [.w], edx
+
+        imul    eax, edx
+        mov     [.subrect_bytes], eax
+
+        ; check bounds
+        mov     ebx, [mem_BACKGROUND]
+        add     ebx, 4095
+        and     ebx, -4096
+        sub     ebx, 4
+        add     eax, [.subrect_startptr]
+        cmp     eax, ebx
+        ja      .fail_39_3
+
+        ; copy contents
+        mov     edi, [img_background]
+        xor     ecx, ecx ; ecx - row index
+.copy_rect:
+        cmp     ecx, [.h]
+        jae     .end_copy_rect
+        
+        xor     edx, edx ; edx - column index
+.copy_row:
+        cmp     edx, [.w]
+        jae     .end_copy_row
+
+        mov     ebx, ecx
+        imul    ebx, [BgrDataWidth]
+        add     ebx, edx
+        imul    ebx, 3
+        add     ebx, [.subrect_startptr]
+        mov     eax, [edi + ebx]
+        mov     ebx, ecx
+        imul    ebx, [.w]
+        add     ebx, edx
+        and     eax, 0xFFFFFF
+        mov     [esi + ebx*4], eax       
+
+        inc     edx
+        jmp     .copy_row
+.end_copy_row:        
+
+        inc     ecx
+        jmp     .copy_rect
+.end_copy_rect:
+        xor     eax, eax
+        mov     [esp+32], eax
+;--------------------------------------
+align 4
+.fail_39_3:
+        mov     eax, -1
+align 4
+.ret_39_3:
+        ret
+;--------------------------------------
+align 4
+.nogb3:
         dec     ebx
-        dec     ebx
+        jnz     .nogb4
-        jnz     nogb4
+        ; sysfn 39.4:
         mov     eax, [BgrDrawMode]
 ;--------------------------------------
 align 4
-nogb4:
+.nogb4:
         mov     [esp+32], eax
         ret
 ;------------------------------------------------------------------------------