tumbledemerald-legacy/gflib/gpu_regs.c

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2022-05-19 19:14:13 +02:00
#include "global.h"
#include "gpu_regs.h"
#define GPU_REG_BUF_SIZE 0x60
#define GPU_REG_BUF(offset) (*(u16 *)(&sGpuRegBuffer[offset]))
#define GPU_REG(offset) (*(vu16 *)(REG_BASE + offset))
#define EMPTY_SLOT 0xFF
static u8 sGpuRegBuffer[GPU_REG_BUF_SIZE];
static u8 sGpuRegWaitingList[GPU_REG_BUF_SIZE];
static volatile bool8 sGpuRegBufferLocked;
static volatile bool8 sShouldSyncRegIE;
static vu16 sRegIE;
static void CopyBufferedValueToGpuReg(u8 regOffset);
static void SyncRegIE(void);
static void UpdateRegDispstatIntrBits(u16 regIE);
void InitGpuRegManager(void)
{
s32 i;
for (i = 0; i < GPU_REG_BUF_SIZE; i++)
{
sGpuRegBuffer[i] = 0;
sGpuRegWaitingList[i] = EMPTY_SLOT;
}
sGpuRegBufferLocked = FALSE;
sShouldSyncRegIE = FALSE;
sRegIE = 0;
}
static void CopyBufferedValueToGpuReg(u8 regOffset)
{
if (regOffset == REG_OFFSET_DISPSTAT)
{
REG_DISPSTAT &= ~(DISPSTAT_HBLANK_INTR | DISPSTAT_VBLANK_INTR);
REG_DISPSTAT |= GPU_REG_BUF(REG_OFFSET_DISPSTAT);
}
else
{
GPU_REG(regOffset) = GPU_REG_BUF(regOffset);
}
}
void CopyBufferedValuesToGpuRegs(void)
{
if (!sGpuRegBufferLocked)
{
s32 i;
for (i = 0; i < GPU_REG_BUF_SIZE; i++)
{
u8 regOffset = sGpuRegWaitingList[i];
if (regOffset == EMPTY_SLOT)
return;
CopyBufferedValueToGpuReg(regOffset);
sGpuRegWaitingList[i] = EMPTY_SLOT;
}
}
}
void SetGpuReg(u8 regOffset, u16 value)
{
if (regOffset < GPU_REG_BUF_SIZE)
{
u16 vcount;
GPU_REG_BUF(regOffset) = value;
vcount = REG_VCOUNT & 0xFF;
if ((vcount >= 161 && vcount <= 225) || (REG_DISPCNT & DISPCNT_FORCED_BLANK))
{
CopyBufferedValueToGpuReg(regOffset);
}
else
{
s32 i;
sGpuRegBufferLocked = TRUE;
for (i = 0; i < GPU_REG_BUF_SIZE && sGpuRegWaitingList[i] != EMPTY_SLOT; i++)
{
if (sGpuRegWaitingList[i] == regOffset)
{
sGpuRegBufferLocked = FALSE;
return;
}
}
sGpuRegWaitingList[i] = regOffset;
sGpuRegBufferLocked = FALSE;
}
}
}
void SetGpuReg_ForcedBlank(u8 regOffset, u16 value)
{
if (regOffset < GPU_REG_BUF_SIZE)
{
GPU_REG_BUF(regOffset) = value;
if (REG_DISPCNT & DISPCNT_FORCED_BLANK)
{
CopyBufferedValueToGpuReg(regOffset);
}
else
{
s32 i;
sGpuRegBufferLocked = TRUE;
for (i = 0; i < GPU_REG_BUF_SIZE && sGpuRegWaitingList[i] != EMPTY_SLOT; i++)
{
if (sGpuRegWaitingList[i] == regOffset)
{
sGpuRegBufferLocked = FALSE;
return;
}
}
sGpuRegWaitingList[i] = regOffset;
sGpuRegBufferLocked = FALSE;
}
}
}
u16 GetGpuReg(u8 regOffset)
{
if (regOffset == REG_OFFSET_DISPSTAT)
return REG_DISPSTAT;
if (regOffset == REG_OFFSET_VCOUNT)
return REG_VCOUNT;
return GPU_REG_BUF(regOffset);
}
void SetGpuRegBits(u8 regOffset, u16 mask)
{
u16 regValue = GPU_REG_BUF(regOffset);
SetGpuReg(regOffset, regValue | mask);
}
void ClearGpuRegBits(u8 regOffset, u16 mask)
{
u16 regValue = GPU_REG_BUF(regOffset);
SetGpuReg(regOffset, regValue & ~mask);
}
static void SyncRegIE(void)
{
if (sShouldSyncRegIE)
{
u16 temp = REG_IME;
REG_IME = 0;
REG_IE = sRegIE;
REG_IME = temp;
sShouldSyncRegIE = FALSE;
}
}
void EnableInterrupts(u16 mask)
{
sRegIE |= mask;
sShouldSyncRegIE = TRUE;
SyncRegIE();
UpdateRegDispstatIntrBits(sRegIE);
}
void DisableInterrupts(u16 mask)
{
sRegIE &= ~mask;
sShouldSyncRegIE = TRUE;
SyncRegIE();
UpdateRegDispstatIntrBits(sRegIE);
}
static void UpdateRegDispstatIntrBits(u16 regIE)
{
u16 oldValue = GetGpuReg(REG_OFFSET_DISPSTAT) & (DISPSTAT_HBLANK_INTR | DISPSTAT_VBLANK_INTR);
u16 newValue = 0;
if (regIE & INTR_FLAG_VBLANK)
newValue |= DISPSTAT_VBLANK_INTR;
if (regIE & INTR_FLAG_HBLANK)
newValue |= DISPSTAT_HBLANK_INTR;
if (oldValue != newValue)
SetGpuReg(REG_OFFSET_DISPSTAT, newValue);
}