From 989dbcc76d04edabcfe99e2f54dd778d86b62818 Mon Sep 17 00:00:00 2001
From: Erik Abair <erik.abair@gmail.com>
Date: Tue, 10 May 2022 06:40:45 -0700
Subject: [PATCH] nv2a: Match HW behavior when setting window clip

---
 hw/xbox/nv2a/pgraph.c | 15 ++++++++++-----
 hw/xbox/nv2a/psh.c    | 10 ++++++----
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/hw/xbox/nv2a/pgraph.c b/hw/xbox/nv2a/pgraph.c
index e877ad4962..22811f54d6 100644
--- a/hw/xbox/nv2a/pgraph.c
+++ b/hw/xbox/nv2a/pgraph.c
@@ -1507,13 +1507,17 @@ DEF_METHOD(NV097, SET_WINDOW_CLIP_TYPE)
 DEF_METHOD_INC(NV097, SET_WINDOW_CLIP_HORIZONTAL)
 {
     int slot = (method - NV097_SET_WINDOW_CLIP_HORIZONTAL) / 4;
-    pg->regs[NV_PGRAPH_WINDOWCLIPX0 + slot * 4] = parameter;
+    for (; slot < 8; ++slot) {
+        pg->regs[NV_PGRAPH_WINDOWCLIPX0 + slot * 4] = parameter;
+    }
 }
 
 DEF_METHOD_INC(NV097, SET_WINDOW_CLIP_VERTICAL)
 {
     int slot = (method - NV097_SET_WINDOW_CLIP_VERTICAL) / 4;
-    pg->regs[NV_PGRAPH_WINDOWCLIPY0 + slot * 4] = parameter;
+    for (; slot < 8; ++slot) {
+        pg->regs[NV_PGRAPH_WINDOWCLIPY0 + slot * 4] = parameter;
+    }
 }
 
 DEF_METHOD(NV097, SET_ALPHA_TEST_ENABLE)
@@ -4075,6 +4079,7 @@ static void pgraph_shader_update_constants(PGRAPHState *pg,
     }
 
     /* Clipping regions */
+    int max_gl_height = pg->surface_binding_dim.height - 1;
     for (i = 0; i < 8; i++) {
         uint32_t x = pg->regs[NV_PGRAPH_WINDOWCLIPX0 + i * 4];
         unsigned int x_min = GET_MASK(x, NV_PGRAPH_WINDOWCLIPX0_XMIN);
@@ -4086,9 +4091,9 @@ static void pgraph_shader_update_constants(PGRAPHState *pg,
         pgraph_apply_anti_aliasing_factor(pg, &x_max, &y_max);
 
         /* Translate for the GL viewport origin */
-        unsigned int y_min_xlat = MAX(pg->surface_binding_dim.height - y_max - 1, 0);
-        unsigned int y_max_xlat = MIN(pg->surface_binding_dim.height - y_min - 1,
-                                      pg->surface_binding_dim.height);
+        unsigned int y_min_xlat = MAX(max_gl_height - (int)y_max, 0);
+        unsigned int y_max_xlat = MIN(max_gl_height - (int)y_min, max_gl_height);
+
         pgraph_apply_scaling_factor(pg, &x_min, &y_min_xlat);
         pgraph_apply_scaling_factor(pg, &x_max, &y_max_xlat);
 
diff --git a/hw/xbox/nv2a/psh.c b/hw/xbox/nv2a/psh.c
index bb70ee1cb9..9a7b1de649 100644
--- a/hw/xbox/nv2a/psh.c
+++ b/hw/xbox/nv2a/psh.c
@@ -652,10 +652,12 @@ static MString* psh_convert(struct PixelShader *ps)
     if (!ps->state.window_clip_exclusive) {
         mstring_append(clip, "bool clipContained = false;\n");
     }
-    mstring_append(clip, "for (int i = 0; i < 8; i++) {\n"
-                         "  bvec4 clipTest = bvec4(lessThan(gl_FragCoord.xy-0.5, vec2(clipRegion[i].xy)),\n"
-                         "                         greaterThan(gl_FragCoord.xy-0.5, vec2(clipRegion[i].zw)));\n"
-                         "  if (!any(clipTest)) {\n");
+    mstring_append(clip, "vec2 coord = gl_FragCoord.xy - 0.5;\n"
+                         "for (int i = 0; i < 8; i++) {\n"
+                         "  bool outside = any(bvec4(\n"
+                         "      lessThan(coord, vec2(clipRegion[i].xy)),\n"
+                         "      greaterThan(coord, vec2(clipRegion[i].zw))));\n"
+                         "  if (!outside) {\n");
     if (ps->state.window_clip_exclusive) {
         mstring_append(clip, "    discard;\n");
     } else {