From 161c6ce24aca185dea604b05e7fbc47852118218 Mon Sep 17 00:00:00 2001
From: EllipticEllipsis <73679967+EllipticEllipsis@users.noreply.github.com>
Date: Sun, 26 Dec 2021 23:37:26 +0000
Subject: [PATCH] viswapcontext OK (#427)

---
 src/libultra/io/viswapcontext.c | 65 ++++++++++++++++++++++++++++++++-
 1 file changed, 64 insertions(+), 1 deletion(-)

diff --git a/src/libultra/io/viswapcontext.c b/src/libultra/io/viswapcontext.c
index 014fbbfeb7..514e3aa1df 100644
--- a/src/libultra/io/viswapcontext.c
+++ b/src/libultra/io/viswapcontext.c
@@ -1,3 +1,66 @@
 #include "global.h"
 
-#pragma GLOBAL_ASM("asm/non_matchings/boot/viswapcontext/__osViSwapContext.s")
+void __osViSwapContext(void) {
+    register OSViMode* viMode;
+    register __OSViContext* viNext;
+    u32 origin;
+    u32 hStart;
+    u32 vstart;
+    u32 sp34;
+    u32 field;
+    register u32 s2;
+
+    field = 0;
+    viNext = __osViNext;
+    viMode = viNext->modep;
+    field = HW_REG(VI_V_CURRENT_LINE_REG, u32) & 1;
+    s2 = osVirtualToPhysical(viNext->buffer);
+    origin = (viMode->fldRegs[field].origin) + s2;
+    if (viNext->state & 2) {
+        viNext->x.scale |= viMode->comRegs.xScale & ~0xFFF;
+    } else {
+        viNext->x.scale = viMode->comRegs.xScale;
+    }
+    if (viNext->state & 4) {
+        sp34 = (u32)(viMode->fldRegs[field].yScale & 0xFFF);
+        viNext->y.scale = viNext->y.factor * sp34;
+        viNext->y.scale |= viMode->fldRegs[field].yScale & ~0xFFF;
+    } else {
+        viNext->y.scale = viMode->fldRegs[field].yScale;
+    }
+
+    vstart = (viMode->fldRegs[field].vStart - (__additional_scanline << 0x10)) + __additional_scanline;
+    hStart = viMode->comRegs.hStart;
+
+    if (viNext->state & 0x20) {
+        hStart = 0;
+    }
+
+    if (viNext->state & 0x40) {
+        viNext->y.scale = 0;
+        origin = osVirtualToPhysical(viNext->buffer);
+    }
+
+    if (viNext->state & 0x80) {
+        viNext->y.scale = (viNext->y.offset << 0x10) & 0x3FF0000;
+        origin = osVirtualToPhysical(viNext->buffer);
+    }
+
+    HW_REG(VI_ORIGIN_REG, u32) = origin;
+    HW_REG(VI_WIDTH_REG, u32) = viMode->comRegs.width;
+    HW_REG(VI_BURST_REG, u32) = viMode->comRegs.burst;
+    HW_REG(VI_V_SYNC_REG, u32) = viMode->comRegs.vSync;
+    HW_REG(VI_H_SYNC_REG, u32) = viMode->comRegs.hSync;
+    HW_REG(VI_LEAP_REG, u32) = viMode->comRegs.leap;
+    HW_REG(VI_H_START_REG, u32) = hStart;
+    HW_REG(VI_V_START_REG, u32) = vstart;
+    HW_REG(VI_V_BURST_REG, u32) = viMode->fldRegs[field].vBurst;
+    HW_REG(VI_INTR_REG, u32) = viMode->fldRegs[field].vIntr;
+    HW_REG(VI_X_SCALE_REG, u32) = viNext->x.scale;
+    HW_REG(VI_Y_SCALE_REG, u32) = viNext->y.scale;
+    HW_REG(VI_CONTROL_REG, u32) = viNext->features;
+
+    __osViNext = __osViCurr;
+    __osViCurr = viNext;
+    *__osViNext = *__osViCurr;
+}