From 4bd1a07706a2a65abe3c665671cd12caf9f54e12 Mon Sep 17 00:00:00 2001
From: Antonio Abbatangelo <antonio.abbatangelo@gmail.com>
Date: Thu, 10 Feb 2022 21:18:09 -0500
Subject: [PATCH] nv2a: adjust display resolution in 1080i mode

---
 hw/xbox/nv2a/nv2a_regs.h | 4 ++++
 hw/xbox/nv2a/pgraph.c    | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/hw/xbox/nv2a/nv2a_regs.h b/hw/xbox/nv2a/nv2a_regs.h
index 8e0110f2d1..05de51bbbe 100644
--- a/hw/xbox/nv2a/nv2a_regs.h
+++ b/hw/xbox/nv2a/nv2a_regs.h
@@ -619,6 +619,10 @@
 #define NV_PCRTC_RASTER                                  0x00000808
 
 
+#define NV_PRMCIO_INTERLACE_MODE                         0x00000039
+#   define NV_PRMCIO_INTERLACE_MODE_DISABLED                    0xff
+
+
 #define NV_PVIDEO_INTR                                   0x00000100
 #   define NV_PVIDEO_INTR_BUFFER_0                              (1 << 0)
 #   define NV_PVIDEO_INTR_BUFFER_1                              (1 << 4)
diff --git a/hw/xbox/nv2a/pgraph.c b/hw/xbox/nv2a/pgraph.c
index 94de42a5fb..2c978acd12 100644
--- a/hw/xbox/nv2a/pgraph.c
+++ b/hw/xbox/nv2a/pgraph.c
@@ -4910,6 +4910,11 @@ static void pgraph_render_display(NV2AState *d, SurfaceBinding *surface)
     d->vga.get_offsets(&d->vga, &pline_offset, &pstart_addr, &pline_compare);
     int line_offset = surface->pitch / pline_offset;
 
+    /* Adjust viewport height for interlaced mode, used only in 1080i */
+    if (d->vga.cr[NV_PRMCIO_INTERLACE_MODE] != NV_PRMCIO_INTERLACE_MODE_DISABLED) {
+        height *= 2;
+    }
+
     pgraph_apply_scaling_factor(pg, &width, &height);
 
     glBindFramebuffer(GL_FRAMEBUFFER, d->pgraph.disp_rndr.fbo);