/* ARM assembly Raspberry PI or android 32 bits with termux application */
/*  program animLetter.s        */

/* compile with as         */
/* link with gcc and options -lX11 -L/usr/lpp/X11/lib   */

/* REMARK: This program was written for android with the termux app.
 It works very well on raspberry pi but in this case the memory access relocation instructions
 can be simplified.
*/

 /* REMARK 1 : this program use routines in a include file
   see task Include a file language arm assembly
   for the routine affichageMess conversion10
   see at end of this program the instruction include */
/* for constantes see task include a file in arm assembly */
/************************************/
/* Constantes                       */
/************************************/
.include "../constantes.inc"

/********************************************/
/*Constantes                                */
/********************************************/
.equ STDOUT,              1     @ Linux output console
.equ EXIT,                1     @ Linux syscall
.equ WRITE,               4     @ Linux syscall
/* constantes X11 */
.equ KeyPressed,          2
.equ ButtonPress,         4
.equ MotionNotify,        6
.equ EnterNotify,         7
.equ LeaveNotify,         8
.equ Expose,              12
.equ ClientMessage,       33
.equ KeyPressMask,        1
.equ ButtonPressMask,     4
.equ ButtonReleaseMask,   8
.equ ExposureMask,        1<<15
.equ StructureNotifyMask, 1<<17
.equ EnterWindowMask,     1<<4
.equ LeaveWindowMask,     1<<5
.equ ConfigureNotify,     22

.equ GCForeground,        1<<2
.equ GCFont,              1<<14

/* constantes program */
.equ WINDOWWIDTH,       400
.equ WINDOWHEIGHT,      300

/*******************************************/
/* DONNEES INITIALISEES                    */
/*******************************************/
.data
szWindowName:            .asciz "Windows Raspberry"
szRetourligne:           .asciz  "\n"
szMessDebutPgm:          .asciz "Program start. \n"
szMessErreur:            .asciz "Server X not found.\n"
szMessErrfen:            .asciz "Can not create window.\n"
szMessErreurX11:         .asciz "Error call function X11. \n"
szMessErrGc:             .asciz "Can not create graphics context.\n"
szMessErrFont:           .asciz "Font not found.\n"
szTitreFenRed:           .asciz "Pi"
szTexte1:                .asciz "Hello world!  "
.equ LGTEXTE1, . - szTexte1
szTexte2:                .asciz "Press q for close window or clic X in system menu."
.equ LGTEXTE2, . - szTexte2
szLibDW:           .asciz "WM_DELETE_WINDOW"    @ special label for correct close error

szfontname: .asciz  "-*-helvetica-bold-*-normal-*-12-*"         @ for font test
szfontname2: .asciz "-*-fixed-*-*-*-*-13-*-*-*-*-*"
.align 4
stXGCValues:       .int 0,0,0xFFA0A0A0,0,0,0,0,0,0,0,0,0,0,0,0,0,0   @ for foreground color gris1
//stXGCValues:       .int 0,0,0x00000000,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0   @ for foreground color black
stXGCValues1:      .int 0,0,0x00FFFFFF,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0   @ for foreground color white
stXGCValues2:      .int 0,0,0x0000FF00,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0   @ for foreground color green
/*******************************************/
/* DONNEES NON INITIALISEES                    */
/*******************************************/
.bss
.align 4
ptDisplay:          .skip 4      @ pointer display
ptEcranDef:         .skip 4      @ pointer screen default
ptFenetre:          .skip 4      @ pointer window
ptGC:               .skip 4      @ pointer graphic context
ptGC1:              .skip 4      @ pointer graphic context
ptFont:             .skip 4      @ pointer font
key:                .skip 4      @ key code
wmDeleteMessage:    .skip 8      @ ident close message
event:              .skip 400    @ TODO: event size ??
PrpNomFenetre:      .skip 100    @ window name proprety
buffer:             .skip 500
sbuffer1:             .skip 500
iWhite:             .skip 4      @ rgb code for white pixel
iBlack:             .skip 4      @ rgb code for black pixel
iSens:              .skip 4      @ direction of travel
/**********************************************/
/* -- Code section                            */
/**********************************************/
.text
.global main
iOfWhite:           .int iWhite - .
iOfBlack:           .int iBlack - .
iOfszMessDebutPgm:  .int szMessDebutPgm - .
iOfptDisplay:       .int ptDisplay - .
iOfptEcranDef:      .int ptEcranDef - .
iOfszLibDW:         .int szLibDW - .
main:                           @ entry of program
    adr r0,iOfszMessDebutPgm   @
    ldr r1,[r0]
    add r0,r1
    bl affichageMess            @ display start message on console linux
    /* attention r6  pointer display*/
    /* attention r8  pointer graphic context 1  */
    /* attention r9 ident window  */
    /* attention r10  pointer graphic context 2  */
    /*****************************/
    /*    OPEN SERVER X11        */
    /*****************************/
    mov r0,#0
    bl XOpenDisplay             @ open X server
    cmp r0,#0                   @ error ?
    beq erreurServeur
    adr r2,iOfptDisplay
    ldr r1,[r2]
    add r1,r2
    str r0,[r1]                 @ store display address

    mov r6,r0                   @ and in register r6
    ldr r2,[r0,#+132]           @ load default_screen
    adr r1,iOfptEcranDef
    ldr r3,[r1]
    add r1,r3
    str r2,[r1]                 @ store default_screen
    mov r2,r0
    ldr r0,[r2,#+140]           @ load pointer screen list
    ldr r5,[r0,#+52]            @ load value white pixel
    adr r4,iOfWhite             @ and store in memory
    ldr r3,[r4]
    add r4,r3
    str r5,[r4]
    ldr r7,[r0,#+56]            @ load value black pixel
    adr r4,iOfBlack             @ and store in memory
    ldr r5,[r4]
    add r4,r5
    str r7,[r4]
    ldr r4,[r0,#+28]            @ load bits par pixel
    ldr r1,[r0,#+8]             @ load root windows
    /**************************/
    /* CREATE WINDOW          */
    /**************************/
    mov r0,r6                   @ address display
    mov r2,#0                   @ window position X
    mov r3,#0                   @ window position Y
    mov r8,#0                   @ for stack alignement
    push {r8}
    push {r7}                   @  background  = black pixel
    push {r5}                   @  border = white pixel
    mov r8,#2                   @  border size
    push {r8}
    mov r8,#WINDOWHEIGHT        @ height
    push {r8}
    mov r8,#WINDOWWIDTH         @ width
    push {r8}
    bl XCreateSimpleWindow
    add sp,#24                  @ stack alignement  6 push (4 bytes * 6)
    cmp r0,#0                   @ error ?
    beq erreurF

    adr r1,iOfptFenetre
    ldr r3,[r1]
    add r1,r3
    str r0,[r1]                 @ store window address in memory
    mov r9,r0                   @ and in register r9

    /*****************************/
    /* add window property       */
    /*****************************/
    mov r0,r6                   @ display address
    mov r1,r9                   @ window address
    adr r2,iOfszWindowName      @ window name
    ldr r5,[r2]
    add r2,r5
    adr r3,iOfszTitreFenRed     @ window name reduced
    ldr r5,[r3]
    add r3,r5
    mov r4,#0
    push {r4}                   @ parameters not use
    push {r4}
    push {r4}
    push {r4}
    bl XSetStandardProperties
    add sp,sp,#16               @ stack alignement for 4 push
    /**************************************/
    /* for correction window close error  */
    /**************************************/
    mov r0,r6                   @ display address
    adr r1,iOfszLibDW           @ atom address
    ldr r5,[r1]
    add r1,r5
    mov r2,#1                   @ False  créate atom if not exists
    bl XInternAtom
    cmp r0,#0                   @ error X11 ?
    blt erreurX11               @ Modif avril 22 pour android (ble pour raspberry)
    adr r1,iOfwmDeleteMessage  @ recept address
    ldr r5,[r1]
    add r1,r5
    str r0,[r1]
    mov r2,r1                   @ return address
    mov r0,r6                   @ display address
    mov r1,r9                   @ window address
    mov r3,#1                   @ number of protocols
    bl XSetWMProtocols
    cmp r0,#0                   @ error X11 ?
    ble erreurX11
    /***********************************/
    /* load font                       */
    /* remark : see font list X11 on your system */
    /***********************************/
    mov r0,r6                   @ display address
    bl loadFont

    /**********************************/
    /*  create graphic context        */
    /**********************************/
    mov r0,r6                   @ display address
    mov r1,r9                   @ window address
    bl createContextGraphic


    /****************************/
    /* modif window background  */
    /****************************/
    mov r0,r6                   @ display address
    mov r1,r9                   @ window address
    ldr r2,iGris1               @ background color
    bl XSetWindowBackground
    cmp r0,#0                   @ error ?
    ble erreurX11

    /***************************/
    /* OUF!! window display    */
    /***************************/
    mov r0,r6                   @ display address
    mov r1,r9                   @ window address
    bl XMapWindow

                                @ copy text in buffer
    adr r0,iOfszTexte1          @ string address
    ldr r5,[r0]
    add r0,r5
    adr r1,iOfsbuffer1          @ buffer address
    ldr r5,[r1]
    add r1,r5
    mov r2,#0
1:                              @ loop copy character
    ldrb r3,[r0,r2]
    strb r3,[r1,r2]
    cmp r3,#0
    addne r2,r2,#1
    bne 1b

    /****************************/
    /* Autorisations            */
    /****************************/
    mov r0,r6                   @ display address
    mov r1,r9                   @ window address
    ldr r2,iFenetreMask         @ autorisation mask
    bl XSelectInput
    cmp r0,#0                   @ error ?
    ble erreurX11

    /****************************/
    /* Events loop              */
    /****************************/
1:
    mov r0,r6                   @ display address
    bl XPending                 @ loading the number of events
    cmp r0,#0
    bne 2f                      @ a event is occurring
    adr r3,iOfsbuffer1
    ldr r5,[r3]
    add r3,r5
    mov r0,r6                   @ display address
    mov r1,r9                   @ window ident
    mov r2,r8                   @ graphic context
    bl animate                  @ string display and move
    b 1b
2:
    mov r0,r6                   @ display address
    adr r1,iOfevent             @ events address
    ldr r5,[r1]
    add r1,r5
    bl XNextEvent               @ event ?
    adr r0,iOfevent
    ldr r5,[r0]
    add r0,r5
    ldr r0,[r0]                 @ code event
    cmp r0,#KeyPressed          @ key ?
    bne 2f
    adr r0,iOfevent            @ yes read key in buffer
    ldr r5,[r0]
    add r0,r5
    adr r1,iOfbuffer
    ldr r5,[r1]
    add r1,r5
    mov r2,#255
    adr r3,iOfkey
    ldr r5,[r3]
    add r3,r5
    mov r4,#0
    push {r4}                   @ stack alignement
    push {r4}
    bl XLookupString
    add sp,#8                   @ stack alignement 2 push
    cmp r0,#1                   @ is character key ?
    bne 2f
    adr r0,iOfbuffer           @ yes -> load first buffer character
    ldr r5,[r0]
    add r0,r5
    ldrb r0,[r0]
    cmp r0,#0x71                @ character q for quit
    beq 5f                      @ yes -> end
    b 4f
2:
    /************************************/
    /*  clic mouse button   */
    /************************************/
    cmp r0,#ButtonPress         @ clic mouse buton
    bne 3f
    adr r0,iOfevent
    ldr r5,[r0]
    add r0,r5
    ldr r1,[r0,#+32]            @ position X mouse clic
    ldr r2,[r0,#+36]            @ position Y
    cmp r1,#50                  @ test if position clic is on the screen string approx.
    blt 4f
    cmp r1,#150
    bgt 4f
    cmp r2,#80
    blt 4f
    cmp r2,#105
    bgt 4f
    adr r1,iOfiSens             @ load direction
    ldr r2,[r1]
    add r1,r2
    ldr r2,[r1]
    cmp r2,#0                   @ direction inversion
    moveq r2,#1
    movne r2,#0
    str r2,[r1]
    b 4f
3:
    cmp r0,#ClientMessage       @ code for close window within error
    bne 4f
    adr r0,iOfevent
    ldr r5,[r0]
    add r0,r5
    ldr r1,[r0,#+28]            @ code message address
    adr r2,iOfwmDeleteMessage   @ equal code window créate ???
    ldr r5,[r2]
    add r2,r5
    ldr r2,[r2]
    cmp r1,r2
    beq 5f                      @ yes -> end window

4:  @ loop for other event
    b 1b
iOfptFenetre:       .int ptFenetre - .
iOfszWindowName:    .int szWindowName - .
iOfszTitreFenRed:   .int szTitreFenRed - .
    /***********************************/
    /* Close window -> free ressources */
    /***********************************/
5:
    mov r0,r6                  @ display address
    adr r1,iOfptGC
    ldr r5,[r1]
    add r1,r5
    ldr r1,[r1]                @ load context graphic address
    bl XFreeGC
    mov r0,r6                  @ display address
    adr r1,iOfptGC1
    ldr r5,[r1]
    add r1,r5
    ldr r1,[r1]                @ load context graphic address
    bl XFreeGC
    cmp r0,#0
    blt erreurX11
    mov r0,r6                  @ display address
    mov r1,r9                  @ window address
    bl XDestroyWindow
    cmp r0,#0
    blt erreurX11
    mov r0,r6                  @ display address
    bl XCloseDisplay
    cmp r0,#0
    blt erreurX11
    mov r0,#0                  @ return code OK
    b 100f

erreurF:   @ create error window but possible not necessary. Display error by server
    adr r1,iOfszMessErrfen
    ldr r5,[r1]
    add r1,r5
    bl   displayError
    mov r0,#1                  @ return error code
    b 100f
erreurGC:                      @ error create graphic context
    adr r1,iOfszMessErrGc
    ldr r5,[r1]
    add r1,r5
    bl   displayError
    mov r0,#1
    b 100f
erreurX11:    @ erreur X11
    adr r1,iOfszMessErreurX11
    ldr r5,[r1]
    add r1,r5
    bl   displayError
    mov r0,#1
    b 100f
erreurServeur:                 @ error no found X11 server see doc putty and Xming
    adr r1,iOfszMessErreur
    ldr r5,[r1]
    add r1,r5
    bl   displayError
    mov r0,#1
    b 100f

100:                           @ standard end of the program
    mov r7, #EXIT
    svc 0

iOfevent:           .int event - .
iOfbuffer:          .int buffer - .
iOfsbuffer1:        .int sbuffer1 - .
iOfkey:             .int key - .
iOfszMessErreurX11: .int szMessErreurX11 - .
iOfszMessErreur:    .int szMessErreur - .
iOfszMessErrfen:    .int szMessErrfen - .
iOfszTexte1:        .int szTexte1 - .
iOfszTexte2:        .int szTexte2 - .
iOfPrpNomFenetre:   .int PrpNomFenetre - .
iOfwmDeleteMessage: .int wmDeleteMessage - .

iFenetreMask:        .int  KeyPressMask|ButtonPressMask|StructureNotifyMask
iGris1:              .int 0xFFA0A0A0
iOfiSens:            .int iSens - .
/******************************************************************/
/*    load font                                                  */
/******************************************************************/
/* r0 contains display  */
loadFont:
    push {r1-r2,lr}           @ save  registers
    adr r1,iOfszfontname       @ font name
    ldr r2,[r1]
    add r1,r2
    bl XLoadQueryFont
    cmp r0,#0
    beq 99f                    @ font not find
    adr r1,iOfptFont
    ldr r2,[r1]
    add r1,r2
    str r0,[r1]
    mov r0,#0
    b 100f
99:
    adr r1,iOfszMessErrFont
    ldr r5,[r1]
    add r1,r5
    bl   displayError
    mov r0,#1
100:
    pop {r1-r2,pc}             @ restaur registers
iOfszfontname:          .int szfontname2 - .
iOfptFont:              .int ptFont - .
iOfszMessErrFont:       .int szMessErrFont - .
/******************************************************************/
/*    Context Graphic création                                                  */
/******************************************************************/
/* r0 contains display  */
/* r1 window address */
/* REMARKS : no standard use registers  return GC1 in r8 and GC2 in r10 */
createContextGraphic:
    push {r1-r7,lr}             @ save  registers
    /**********************************/
    /*  create graphic context        */
    /**********************************/
    mov r6,r0                   @ save display address
    mov r7,r1                   @ save window address
    adr r3,iOfptFont            @ font pointer
    ldr r1,[r3]
    add r3,r1
    ldr r3,[r3]
    ldr r4,[r3,#4]              @ load font ident
    adr r3,iOfstXGCValues2      @ green color in foreground
    ldr r5,[r3]
    add r3,r5                   @ this parameter is used by XcreateGC
    str r4,[r3,#60]             @ store ident font in  offset 60
    mov r0,r4
    mov r0,r6                   @ display address
    mov r1,r7                   @ window address
    mov r2,#GCForeground|GCFont @  @ green color in foreground and font
    bl XCreateGC
    cmp r0,#0                   @ error ?
    beq 99f
    adr r1,iOfptGC
    ldr r5,[r1]
    add r1,r5
    str r0,[r1]                 @ store address graphic context
    mov r8,r0                   @ and in r8
    /**********************************/
    /*  create 2 graphic context        */
    /**********************************/
    mov r0,r6                   @ display address
    mov r1,r7                   @ window address
    mov r2,#GCForeground        @ red color in Foreground
    adr r3,iOfstXGCValues
    ldr r5,[r3]
    add r3,r5
    bl XCreateGC
    cmp r0,#0                   @ error ?
    beq erreurGC
    adr r1,iOfptGC1
    ldr r5,[r1]
    add r1,r5
    str r0,[r1]                 @ store address graphic context
    mov r10,r0                  @ and in r10
    b 100f
99:                            @ create error
    adr r1,iOfszMessErrGc
    ldr r5,[r1]
    add r1,r5
    bl   displayError
    mov r0,#1
100:
    pop {r1-r7,pc}             @ restaur registers
iOfszMessErrGc:     .int szMessErrGc - .
iOfptGC:            .int ptGC - .
iOfptGC1:           .int ptGC1 - .
iOfstXGCValues:     .int stXGCValues - .
iOfstXGCValues1:     .int stXGCValues1 - .
iOfstXGCValues2:     .int stXGCValues2 - .
/******************************************************************/
/*    animation                                                   */
/******************************************************************/
/* r0 contains display  */
/* r1 contains window ident */
/* r2 contains context graphic */
/* r3 string address   */
animate:
    push {r2-r9,lr}            @ save  registers
    mov r5,r3                   @ save string address
    mov r6,r0                   @ save display
    mov r7,r1                   @ save window
    mov r8,r2                   @ save GC
                                @ erase text in the windows
    mov r0,r6                   @ display address
    mov r1,r7                   @ window ident
    mov r2,r10                  @ graphic context
    mov r3,#50                  @ position x
    mov r4,#LGTEXTE1  - 1       @ string lenght
    push {r4}                   @ stack alignement
    push {r4}                   @ to stack parameter

    push {r5}                   @ string address
    mov r4,#100                 @ position y
    push {r4}
    bl XDrawString
    add sp,sp,#16               @ stack alignement (4 push)

    mov r0,#LGTEXTE1 -2         @ string length
    adr r1,iOfiSens             @ load direction
    ldr r2,[r1]
    add r1,r2
    ldr r2,[r1]
    cmp r2,#0                   @ test direction
    bne 2f

    ldrb r9,[r5,r0]             @ last character
    sub r1,r0,#1
1:                              @ loop to move character one position
    ldrb r2,[r5,r1]
    strb r2,[r5,r0]
    sub r0,r0,#1
    subs r1,r1,#1
    bge 1b
    add r1,r1,#1
    strb r9,[r5,r1]             @ last character -> first character
    b 4f
2:
    ldrb r9,[r5]                @ first character
    mov r1,#1
    sub r2,r1,#1
3:                              @ loop to move character
    ldrb r3,[r5,r1]
    strb r3,[r5,r2]
    add r2,r2,#1
    add r1,r1,#1
    cmp r1,r0
    ble 3b
    strb r9,[r5,r2]             @ first character -> last character

4:
                                @ write text in the windows
    mov r0,r6                   @ display address
    mov r1,r7                   @ window ident
    mov r2,r8                   @ graphic context
    mov r3,#50                  @ position x
    mov r4,#LGTEXTE1  - 1       @ string lenght
    push {r4}                   @ stack alignement
    push {r4}                   @ to stack parameter
    push {r5}                   @ string address
    mov r4,#100                 @ position y
    push {r4}
    bl XDrawString
    add sp,sp,#16               @ stack alignement (4 push)
    mov r0,#20                  @ timeout 5s approx.
    bl delay

100:
    pop {r2-r9,pc}             @ restaur registers
/******************************************************************/
/*    timeout                                                   */
/******************************************************************/
/* r0 contains delay  */

delay:
    push {r1,lr}           @ save  registers
    ldr r1,iCst30000000
    mul r0,r1,r0
1:
    subs r0,r0,#1
    bge 1b
100:
    pop {r1,pc}             @ restaur registers
iCst30000000:       .int 30000000
/***************************************************/
/*      ROUTINES INCLUDE                 */
/***************************************************/
.include "../affichage.inc"