gte: backport fix for RTPS/RTPT

Fix glitched drawing of road surface in 'Burning Road'..
behavior now matches Mednafen. This also preserves the fix by Shalma
from prior commit f916013 for missing elements in 'Legacy of Kain:
Soul Reaver' (missing green plasma balls in first level).

- backported fix from pcsx4all
https://github.com/dmitrysmagin/pcsx4all/pull/41/commits/a6ff7d29d615bdb26b491f4e1e2a9f4608a8d643
- fixes R4 - Ridge Racer Type 4 lighting issue

diff --git a/libpcsxcore/gte.c b/libpcsxcore/gte.c
index 62fc7f3..8ef601a 100644 (file)
--- a/libpcsxcore/gte.c
+++ b/libpcsxcore/gte.c
@@ -404,6 +404,7 @@ static u32 DIVIDE_(s16 n, u16 d) {
 
 void gteRTPS(psxCP2Regs *regs) {
        int quotient;
+       s64 tmp;
 
 #ifdef GTE_LOG
        GTE_LOG("GTE RTPS\n");
@@ -426,14 +427,16 @@ void gteRTPS(psxCP2Regs *regs) {
        gteSX2 = limG1(F((s64)gteOFX + ((s64)gteIR1 * quotient)) >> 16);
        gteSY2 = limG2(F((s64)gteOFY + ((s64)gteIR2 * quotient)) >> 16);
 
-       gteMAC0 = F((s64)gteDQB + ((s64)gteDQA * quotient));
-       gteIR0 = limH(gteMAC0 >> 12);
+       tmp = (s64)gteDQB + ((s64)gteDQA * quotient);
+       gteMAC0 = F(tmp);
+       gteIR0 = limH(tmp >> 12);
 }
 
 void gteRTPT(psxCP2Regs *regs) {
        int quotient;
        int v;
        s32 vx, vy, vz;
+       s64 tmp;
 
 #ifdef GTE_LOG
        GTE_LOG("GTE RTPT\n");
@@ -456,8 +459,10 @@ void gteRTPT(psxCP2Regs *regs) {
                fSX(v) = limG1(F((s64)gteOFX + ((s64)gteIR1 * quotient)) >> 16);
                fSY(v) = limG2(F((s64)gteOFY + ((s64)gteIR2 * quotient)) >> 16);
        }
-       gteMAC0 = F((s64)gteDQB + ((s64)gteDQA * quotient));
-       gteIR0 = limH(gteMAC0 >> 12);
+
+       tmp = (s64)gteDQB + ((s64)gteDQA * quotient);
+       gteMAC0 = F(tmp);
+       gteIR0 = limH(tmp >> 12);
 }
 
 void gteMVMVA(psxCP2Regs *regs) {