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view src/hermes/x86p_16.asm @ 4139:568c9b3c0167 SDL-1.2

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* Added configure option --enable-screensaver, to allow enabling the screensaver by default. * Use XResetScreenSaver() instead of disabling screensaver entirely. Full discussion summary from Erik on the SDL mailing list: Current behaviour ================= SDL changes the user's display power management settings without permission from the user and without telling the user. The interface that it uses to do so is DPMSDisable/DPMSEnable, which should only ever be used by configuration utilities like KControl, never by normal application programs, let alone by the libraries that they use. Using an interface that is not at all intended for what SDL tries to achieve means that it will not work as it should. Firstly, the power management is completely disabled during the whole lifetime of the SDL program, not only when it should be. Secondly, it makes SDL non-reentrant, meaning that things will break when multiple SDL programs are clients of the same X server simultaneously. Thirdly, no cleanup mechanism ensures that the setting is restored if the client does not do that (for example if it crashes). In addition to that, this interface is broken on xorg, [http://bugs.freedesktop.org/show_bug.cgi?id=13962], so what SDL tries to do does not work at all on that implementation of the X Window System. (The reason that the DPMSEnable works in KControl is that it calls DPMSSetTimeout immediately after, [http://websvn.kde.org/tags/KDE/3.5.9/kdebase/kcontrol/energy/energy.cpp?annotate=774532#l343]). The problems that the current behaviour causes ============================================== 1. Information leak. When the user is away, someone might see what the user has on the display when the user counts on the screensaver preventing this. This does not even require physical access to the workstation, it is enough to see it from a distance. 2. Draining battery. An SDL program that runs on a laptop will quickly drain the battery while the user is away. The system will soon shut down and require recharging before being usable again, while it should in fact have consumed very little energy if the user's settings would have been obeyed. 3. Wasting energy. Even if battery issues are not considered, energy as such is wasted. 4. Display wear. The display may be worn out. The problems that the current behaviour tries to solve ====================================================== 1. Preventing screensaver while playing movies. Many SDL applications are media players. They have reasons to prevent screensavers from being activated while a movie is being played. When a user clicks on the play button it can be interpreted as saying "play this movie, but do not turn off the display while playing it, because I will watch it even though I do not interact with the system". 2. Preventing screensaver when some input bypasses X. Sometimes SDL uses input from another source than the X server, so that the X server is bypassed. This obviously breaks the screensaver handling. SDL tries to work around that. 3. Preventing screensaver when all input bypasses X. There is something called Direct Graphics Access mode, where a program takes control of both the display and the input devices from the X server. This obviously means that the X server can not handle the screensaver alone, since screensaver handling depends on input handling. SDL does not do what it should to help the X server to handle the screensaver. Nor does SDL take care of screeensaver handling itself. SDL simply disables the screensaver completely. How the problems should be solved ================================= The correct way for an application program to prevent the screensaver under X is to call XResetScreenSaver. This was recently discovered and implemented by the mplayer developers, [http://svn.mplayerhq.hu/mplayer?view=rev&revision=25637]. SDL needs to wrap this in an API call (SDL_ResetScreenSaver) and implement it for the other video targets (if they do not have a corresponding call, SDL should do what it takes on that particular target, for example sending fake key events). 1. When a movie is played, the player should reset the screensaver when the animation is advanced to a new frame. The same applies to anything similar, like slideshows. 2. When the X server is handling input, it must handle all input (keyboards, mice, gamepads, ...). This is necessary, not only to be able to handle the screensaver, but also so that it can send the events to the correct (the currently active) client. If there is an input device that the X server can not handle for some reason (such as lack of Plug and Play capability), the program that handles the device as a workaround must simulate what would happen if the X server would have handled the device, by calling XResetScreenSaver when input is received from the device. 3. When the X server is not handling the input, it depends on the program that does to call XResetScreenSaver whenever an input event occurs. Alternatively the program must handle the screensaver countdown internally and call XActivateScreenSaver.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 29 Feb 2008 13:55:44 +0000
parents 540466e900db
children
line wrap: on
line source

;
; x86 format converters for HERMES
; Copyright (c) 1998 Glenn Fielder (gaffer@gaffer.org)
; This source code is licensed under the GNU LGPL
; 
; Please refer to the file COPYING.LIB contained in the distribution for
; licensing conditions		
; 
; Routines adjusted for Hermes by Christian Nentwich (brn@eleet.mcb.at)
; Used with permission.
; 

BITS 32

%include "common.inc"

SDL_FUNC _ConvertX86p16_16BGR565
SDL_FUNC _ConvertX86p16_16RGB555
SDL_FUNC _ConvertX86p16_16BGR555
SDL_FUNC _ConvertX86p16_8RGB332

EXTERN _ConvertX86

SECTION .text

_ConvertX86p16_16BGR565:

    ; check short
    cmp ecx,BYTE 16
    ja .L3


.L1 ; short loop
    mov al,[esi]
    mov ah,[esi+1]
    mov ebx,eax
    mov edx,eax
    shr eax,11
    and eax,BYTE 11111b
    and ebx,11111100000b
    shl edx,11
    add eax,ebx
    add eax,edx
    mov [edi],al
    mov [edi+1],ah
    add esi,BYTE 2
    add edi,BYTE 2
    dec ecx
    jnz .L1
.L2
    retn

.L3 ; head
    mov eax,edi
    and eax,BYTE 11b
    jz .L4
    mov al,[esi]
    mov ah,[esi+1]
    mov ebx,eax
    mov edx,eax
    shr eax,11
    and eax,BYTE 11111b
    and ebx,11111100000b
    shl edx,11
    add eax,ebx
    add eax,edx
    mov [edi],al
    mov [edi+1],ah
    add esi,BYTE 2
    add edi,BYTE 2
    dec ecx

.L4 ; save count
    push ecx

    ; unroll twice
    shr ecx,1
    
    ; point arrays to end
    lea esi,[esi+ecx*4]
    lea edi,[edi+ecx*4]

    ; negative counter 
    neg ecx
    jmp SHORT .L6
                              
.L5     mov [edi+ecx*4-4],eax
.L6     mov eax,[esi+ecx*4]

        mov ebx,[esi+ecx*4]
        and eax,07E007E0h         

        mov edx,[esi+ecx*4]
        and ebx,0F800F800h

        shr ebx,11
        and edx,001F001Fh

        shl edx,11
        add eax,ebx

        add eax,edx                 
        inc ecx

        jnz .L5                 
         
    mov [edi+ecx*4-4],eax

    ; tail
    pop ecx
    and ecx,BYTE 1
    jz .L7
    mov al,[esi]
    mov ah,[esi+1]
    mov ebx,eax
    mov edx,eax
    shr eax,11
    and eax,BYTE 11111b
    and ebx,11111100000b
    shl edx,11
    add eax,ebx
    add eax,edx
    mov [edi],al
    mov [edi+1],ah
    add esi,BYTE 2
    add edi,BYTE 2

.L7
    retn






_ConvertX86p16_16RGB555:

    ; check short
    cmp ecx,BYTE 32
    ja .L3


.L1 ; short loop
    mov al,[esi]
    mov ah,[esi+1]
    mov ebx,eax
    shr ebx,1
    and ebx,     0111111111100000b
    and eax,BYTE 0000000000011111b
    add eax,ebx
    mov [edi],al
    mov [edi+1],ah
    add esi,BYTE 2
    add edi,BYTE 2
    dec ecx
    jnz .L1
.L2
    retn

.L3 ; head
    mov eax,edi
    and eax,BYTE 11b
    jz .L4
    mov al,[esi]
    mov ah,[esi+1]
    mov ebx,eax
    shr ebx,1
    and ebx,     0111111111100000b
    and eax,BYTE 0000000000011111b
    add eax,ebx
    mov [edi],al
    mov [edi+1],ah
    add esi,BYTE 2
    add edi,BYTE 2
    dec ecx

.L4 ; save ebp
    push ebp

    ; save count
    push ecx

    ; unroll four times
    shr ecx,2
    
    ; point arrays to end
    lea esi,[esi+ecx*8]
    lea edi,[edi+ecx*8]

    ; negative counter 
    xor ebp,ebp
    sub ebp,ecx

.L5     mov eax,[esi+ebp*8]        ; agi?
        mov ecx,[esi+ebp*8+4]
       
        mov ebx,eax
        mov edx,ecx

        and eax,0FFC0FFC0h
        and ecx,0FFC0FFC0h

        shr eax,1
        and ebx,001F001Fh

        shr ecx,1
        and edx,001F001Fh

        add eax,ebx
        add ecx,edx

        mov [edi+ebp*8],eax
        mov [edi+ebp*8+4],ecx

        inc ebp
        jnz .L5                 

    ; tail
    pop ecx
.L6 and ecx,BYTE 11b
    jz .L7
    mov al,[esi]
    mov ah,[esi+1]
    mov ebx,eax
    shr ebx,1
    and ebx,     0111111111100000b
    and eax,BYTE 0000000000011111b
    add eax,ebx
    mov [edi],al
    mov [edi+1],ah
    add esi,BYTE 2
    add edi,BYTE 2
    dec ecx
    jmp SHORT .L6

.L7 pop ebp
    retn






_ConvertX86p16_16BGR555:

    ; check short
    cmp ecx,BYTE 16
    ja .L3

	
.L1 ; short loop
    mov al,[esi]
    mov ah,[esi+1]
    mov ebx,eax
    mov edx,eax
    shr eax,11
    and eax,BYTE 11111b
    shr ebx,1
    and ebx,1111100000b
    shl edx,10
    and edx,0111110000000000b
    add eax,ebx
    add eax,edx
    mov [edi],al
    mov [edi+1],ah
    add esi,BYTE 2
    add edi,BYTE 2
    dec ecx
    jnz .L1
.L2
    retn

.L3 ; head
    mov eax,edi
    and eax,BYTE 11b
    jz .L4
    mov al,[esi]
    mov ah,[esi+1]
    mov ebx,eax
    mov edx,eax
    shr eax,11
    and eax,BYTE 11111b
    shr ebx,1
    and ebx,1111100000b
    shl edx,10
    and edx,0111110000000000b
    add eax,ebx
    add eax,edx
    mov [edi],al
    mov [edi+1],ah
    add esi,BYTE 2
    add edi,BYTE 2
    dec ecx

.L4 ; save count
    push ecx

    ; unroll twice
    shr ecx,1
    
    ; point arrays to end
    lea esi,[esi+ecx*4]
    lea edi,[edi+ecx*4]

    ; negative counter 
    neg ecx
    jmp SHORT .L6
                              
.L5     mov [edi+ecx*4-4],eax
.L6     mov eax,[esi+ecx*4]

        shr eax,1
        mov ebx,[esi+ecx*4]
        
        and eax,03E003E0h         
        mov edx,[esi+ecx*4]

        and ebx,0F800F800h

        shr ebx,11
        and edx,001F001Fh

        shl edx,10
        add eax,ebx

        add eax,edx                 
        inc ecx

        jnz .L5                 
         
    mov [edi+ecx*4-4],eax

    ; tail
    pop ecx
    and ecx,BYTE 1
    jz .L7
    mov al,[esi]
    mov ah,[esi+1]
    mov ebx,eax
    mov edx,eax
    shr eax,11
    and eax,BYTE 11111b
    shr ebx,1
    and ebx,1111100000b
    shl edx,10
    and edx,0111110000000000b
    add eax,ebx
    add eax,edx
    mov [edi],al
    mov [edi+1],ah
    add esi,BYTE 2
    add edi,BYTE 2

.L7
    retn






_ConvertX86p16_8RGB332:

    ; check short
    cmp ecx,BYTE 16
    ja .L3


.L1 ; short loop
    mov al,[esi+0]
    mov ah,[esi+1]
    mov ebx,eax
    mov edx,eax
    and eax,BYTE 11000b         ; blue
    shr eax,3
    and ebx,11100000000b        ; green
    shr ebx,6
    and edx,1110000000000000b   ; red
    shr edx,8
    add eax,ebx
    add eax,edx
    mov [edi],al
    add esi,BYTE 2
    inc edi
    dec ecx
    jnz .L1
.L2
    retn

.L3 mov eax,edi
    and eax,BYTE 11b
    jz .L4
    mov al,[esi+0]
    mov ah,[esi+1]
    mov ebx,eax
    mov edx,eax
    and eax,BYTE 11000b         ; blue
    shr eax,3
    and ebx,11100000000b        ; green
    shr ebx,6
    and edx,1110000000000000b   ; red
    shr edx,8
    add eax,ebx
    add eax,edx
    mov [edi],al
    add esi,BYTE 2
    inc edi
    dec ecx
    jmp SHORT .L3

.L4 ; save ebp
    push ebp

    ; save count
    push ecx

    ; unroll 4 times
    shr ecx,2

    ; prestep
    mov dl,[esi+0]
    mov bl,[esi+1]
    mov dh,[esi+2]
        
.L5     shl edx,16
        mov bh,[esi+3]
        
        shl ebx,16
        mov dl,[esi+4]

        mov dh,[esi+6]
        mov bl,[esi+5]

        and edx,00011000000110000001100000011000b
        mov bh,[esi+7]

        ror edx,16+3
        mov eax,ebx                                     ; setup eax for reds

        and ebx,00000111000001110000011100000111b
        and eax,11100000111000001110000011100000b       ; reds

        ror ebx,16-2
        add esi,BYTE 8

        ror eax,16
        add edi,BYTE 4

        add eax,ebx
        mov bl,[esi+1]                                  ; greens

        add eax,edx
        mov dl,[esi+0]                                  ; blues

        mov [edi-4],eax
        mov dh,[esi+2]

        dec ecx
        jnz .L5                 
    
    ; check tail
    pop ecx
    and ecx,BYTE 11b
    jz .L7

.L6 ; tail
    mov al,[esi+0]
    mov ah,[esi+1]
    mov ebx,eax
    mov edx,eax
    and eax,BYTE 11000b         ; blue
    shr eax,3
    and ebx,11100000000b        ; green
    shr ebx,6
    and edx,1110000000000000b   ; red
    shr edx,8
    add eax,ebx
    add eax,edx
    mov [edi],al
    add esi,BYTE 2
    inc edi
    dec ecx
    jnz .L6

.L7 pop ebp
    retn

%ifidn __OUTPUT_FORMAT__,elf
section .note.GNU-stack noalloc noexec nowrite progbits
%endif