vblank.c

/*
# _____     ___ ____     ___ ____
#  ____|   |    ____|   |        | |____|
# |     ___|   |____ ___|    ____| |    \    PS2DEV Open Source Project.
#-----------------------------------------------------------------------
# Copyright ps2dev - http://www.ps2dev.org
# Licenced under Academic Free License version 2.0
# Review ps2sdk README & LICENSE files for further details.
*/
 
#include "vblank.h"
#include "irx_imports.h"
#include "kerr.h"
 
extern struct irx_export_table _exp_vblank;
 
#ifdef _IOP
IRX_ID("Vblank_service", 1, 1);
#endif
// Based on the module from SCE SDK 1.3.4.
 
static vblank_internals_t vblank_internals;
 
static int irq_vblank_interrupt_handler(void *userdata);
static int irq_evblank_interrupt_handler(void *userdata);
static int vblank_handler_base_beginning(void *userdata);
static int vblank_handler_base_end(void *userdata);
static void linked_list_set_self(vblank_ll_t *ll);
static int linked_list_next_is_self(const vblank_ll_t *ll);
static void linked_list_remove(vblank_ll_t *ll);
static void linked_list_add_after(vblank_ll_t *ll1, vblank_ll_t *ll2);
 
int _start(int ac, char **av)
{
    unsigned int i;
    iop_event_t evfp;
    int state;
 
    (void)ac;
    (void)av;
 
    CpuSuspendIntr(&state);
    if ( RegisterLibraryEntries(&_exp_vblank) )
    {
        CpuResumeIntr(state);
        return 1;
    }
 
    memset(&vblank_internals, 0, sizeof(vblank_internals));
    linked_list_set_self(&vblank_internals.list_00);
    linked_list_set_self(&vblank_internals.list_11);
    linked_list_set_self(&vblank_internals.list_free);
    for ( i = 0; i < (sizeof(vblank_internals.list_items) / sizeof(vblank_internals.list_items[0])); i += 1 )
    {
        linked_list_add_after(&vblank_internals.list_free, &(vblank_internals.list_items[i].ll));
    }
    evfp.bits = 0;
    evfp.attr = EA_MULTI;
    evfp.option = 0;
    vblank_internals.ef = CreateEventFlag(&evfp);
    RegisterVblankHandler(0, 128, vblank_handler_base_beginning, &vblank_internals);
    RegisterVblankHandler(1, 128, vblank_handler_base_end, &vblank_internals);
    RegisterIntrHandler(IOP_IRQ_VBLANK, 1, irq_vblank_interrupt_handler, &vblank_internals);
    RegisterIntrHandler(IOP_IRQ_EVBLANK, 1, irq_evblank_interrupt_handler, &vblank_internals);
    EnableIntr(IOP_IRQ_VBLANK);
    EnableIntr(IOP_IRQ_EVBLANK);
    CpuResumeIntr(state);
    return 0;
}
 
vblank_internals_t *GetVblankInternalData(void)
{
    return &vblank_internals;
}
 
int RegisterVblankHandler(int startend, int priority, int (*handler)(void *userdata), void *arg)
{
    const vblank_ll_t *list;
    vblank_ll_t *item;
    vblank_item_t *item_new;
    int state;
 
    if ( QueryIntrContext() != 0 )
    {
        return KE_ILLEGAL_CONTEXT;
    }
    CpuSuspendIntr(&state);
    if ( linked_list_next_is_self(&vblank_internals.list_free) )
    {
        CpuResumeIntr(state);
        return KE_NO_MEMORY;
    }
    list = &vblank_internals.list_11;
    if ( !startend )
        list = &vblank_internals.list_00;
    item = list->next;
    if ( list->next != list )
    {
        do
        {
            const vblank_item_t *item_vblank;
 
            item_vblank = (vblank_item_t *)item;
            if ( item_vblank->callback == handler )
            {
                CpuResumeIntr(state);
                return KE_FOUND_HANDLER;
            }
            item = item->next;
        } while ( item != list );
        item = list->next;
    }
    for ( ; item != list; item = item->next )
    {
        const vblank_item_t *item_vblank;
 
        item_vblank = (vblank_item_t *)item;
        if ( priority < item_vblank->priority )
            break;
    }
    item_new = (vblank_item_t *)vblank_internals.list_free.next;
    linked_list_remove(vblank_internals.list_free.next);
    item_new->callback = handler;
    item_new->userdata = arg;
    item_new->priority = priority;
    linked_list_add_after(item, &item_new->ll);
    CpuResumeIntr(state);
    return 0;
}
 
// cppcheck-suppress constParameterPointer
int ReleaseVblankHandler(int startend, int (*handler)(void *userdata))
{
    const vblank_ll_t *list;
    vblank_ll_t *item;
    int state;
 
    if ( QueryIntrContext() != 0 )
    {
        return KE_ILLEGAL_CONTEXT;
    }
    CpuSuspendIntr(&state);
    list = &vblank_internals.list_11;
    if ( !startend )
        list = &vblank_internals.list_00;
    item = list->next;
    if ( list->next == list )
    {
        CpuResumeIntr(state);
        return KE_NOTFOUND_HANDLER;
    }
    {
        const vblank_item_t *item_vblank;
 
        item_vblank = (vblank_item_t *)item;
        while ( item_vblank->callback != handler )
        {
            item = item->next;
            item_vblank = (vblank_item_t *)item;
            if ( item == list )
            {
                CpuResumeIntr(state);
                return KE_NOTFOUND_HANDLER;
            }
        }
    }
    linked_list_remove(item);
    linked_list_add_after(&vblank_internals.list_free, item);
    CpuResumeIntr(state);
    return 0;
}
 
static int irq_vblank_interrupt_handler(void *userdata)
{
    int item_count;
    vblank_ll_t *item;
    vblank_ll_t *item_tmp;
    vblank_internals_t *vbi;
 
    vbi = (vblank_internals_t *)userdata;
    item_count = vbi->item_count;
    if ( !item_count )
    {
        iSetEventFlag(GetSystemStatusFlag(), 0x200);
        item_count = vbi->item_count;
    }
    item = vbi->list_00.next;
    vbi->item_count = item_count + 1;
    if ( item != &vbi->list_00 )
    {
        do
        {
            vblank_item_t *item_vblank;
 
            item_vblank = (vblank_item_t *)item;
            item_tmp = item->next;
            if ( item_vblank->callback(item_vblank->userdata) == 0 )
            {
                linked_list_remove(item);
                linked_list_add_after(&vbi->list_free, item);
            }
            item = item_tmp;
        } while ( item_tmp != &vbi->list_00 );
    }
    return 1;
}
 
static int irq_evblank_interrupt_handler(void *userdata)
{
    vblank_ll_t *item;
    const vblank_ll_t *list_tail;
    vblank_ll_t *item_tmp;
    vblank_internals_t *vbi;
 
    vbi = (vblank_internals_t *)userdata;
    item = vbi->list_11.next;
    list_tail = &vbi->list_11;
    if ( item != list_tail )
    {
        do
        {
            vblank_item_t *item_vblank;
 
            item_vblank = (vblank_item_t *)item;
            item_tmp = item->next;
            if ( item_vblank->callback(item_vblank->userdata) == 0 )
            {
                linked_list_remove(item);
                linked_list_add_after(&vbi->list_free, item);
            }
            item = item_tmp;
        } while ( item_tmp != list_tail );
    }
    return 1;
}
 
#define EF_VBLANK_START 1
#define EF_VBLANK_END 4
#define EF_VBLANK 2
#define EF_NON_VBLANK 8
 
static int vblank_handler_base_beginning(void *userdata)
{
    vblank_internals_t *vbi;
 
    vbi = (vblank_internals_t *)userdata;
    iSetEventFlag(vbi->ef, EF_VBLANK_START);
    iSetEventFlag(vbi->ef, EF_VBLANK);
    iClearEventFlag(vbi->ef, ~(9));
    return 1;
}
 
static int vblank_handler_base_end(void *userdata)
{
    vblank_internals_t *vbi;
 
    vbi = (vblank_internals_t *)userdata;
    iSetEventFlag(vbi->ef, EF_VBLANK_END);
    iSetEventFlag(vbi->ef, EF_NON_VBLANK);
    iClearEventFlag(vbi->ef, ~(6));
    return 1;
}
 
void WaitVblankStart()
{
    WaitEventFlag(vblank_internals.ef, EF_VBLANK_START, WEF_OR, NULL);
}
 
void WaitVblankEnd()
{
    WaitEventFlag(vblank_internals.ef, EF_VBLANK_END, WEF_OR, NULL);
}
 
void WaitVblank()
{
    WaitEventFlag(vblank_internals.ef, EF_VBLANK, WEF_OR, NULL);
}
 
void WaitNonVblank()
{
    WaitEventFlag(vblank_internals.ef, EF_NON_VBLANK, WEF_OR, NULL);
}
 
static void linked_list_set_self(vblank_ll_t *ll)
{
    ll->next = ll;
    ll->prev = ll;
}
 
static int linked_list_next_is_self(const vblank_ll_t *ll)
{
    return ll->next == ll;
}
 
static void linked_list_remove(vblank_ll_t *ll)
{
    ll->next->prev = ll->prev;
    ll->prev->next = ll->next;
}
 
#if 0
// This function is unused
static int linked_list_is_circular(vblank_ll_t *ll)
{
    return ll->prev == ll->next;
}
#endif
 
static void linked_list_add_after(vblank_ll_t *ll1, vblank_ll_t *ll2)
{
    ll2->next = ll1;
    ll2->prev = ll1->prev;
    ll1->prev = ll2;
    ll2->prev->next = ll2;
}