From 0a7e0191354a90db14827ccaa3546831397e6c1c Mon Sep 17 00:00:00 2001
From: Erik Abair <erik.abair@gmail.com>
Date: Sun, 12 Oct 2025 17:03:26 -0700
Subject: [PATCH] nv2a: Handle cubemap textures passed to 2D projective
 samplers

Tests: https://github.com/abaire/nxdk_pgraph_tests/blob/bb915c94798906b325cc011383e1c2c270515d50/src/tests/texture_3d_as_2d_tests.cpp#L39
HW results: https://abaire.github.io/nxdk_pgraph_tests_golden_results/results/Texture_3D_as_2D/index.html

Fixes #2384
---
 hw/xbox/nv2a/pgraph/glsl/psh.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/hw/xbox/nv2a/pgraph/glsl/psh.c b/hw/xbox/nv2a/pgraph/glsl/psh.c
index e2d1ee66971..d9d43256a5e 100644
--- a/hw/xbox/nv2a/pgraph/glsl/psh.c
+++ b/hw/xbox/nv2a/pgraph/glsl/psh.c
@@ -632,6 +632,9 @@ static const char *get_sampler_type(struct PixelShader *ps, enum PS_TEXTUREMODES
             if (state->tex_x8y24[i] && ps->opts.vulkan) {
                 return "usampler2D";
             }
+            if (state->tex_cubemap[i]) {
+                return samplerCube;
+            }
             return sampler2D;
         }
         if (dim == 3) return sampler3D;
@@ -959,6 +962,11 @@ static MString* psh_convert(struct PixelShader *ps)
         "    }\n"
         "    return uv;\n"
         "}\n"
+        "\n"
+        "vec3 remap2DToCube(vec3 texCoord2DProjective) {\n"
+        "    vec2 st = (texCoord2DProjective.xy / texCoord2DProjective.z);"
+        "    return normalize(vec3(1.0, st.y, -st.x));"
+        "}\n"
         );
 
     MString *clip = mstring_new();
@@ -1106,8 +1114,17 @@ static MString* psh_convert(struct PixelShader *ps)
                     apply_convolution_filter(ps, vars, i);
                 } else {
                     if (ps->state->dim_tex[i] == 2) {
-                        mstring_append_fmt(vars, "vec4 t%d = textureProj(texSamp%d, %s(pT%d.xyw));\n",
-                                           i, i, tex_remap, i);
+                        if (ps->state->tex_cubemap[i]) {
+                            mstring_append_fmt(
+                                vars,
+                                "vec4 t%d = texture(texSamp%d, remap2DToCube(%s(pT%d.xyw)));\n",
+                                i, i, tex_remap, i);
+                        } else {
+                            mstring_append_fmt(
+                                vars,
+                                "vec4 t%d = textureProj(texSamp%d, %s(pT%d.xyw));\n",
+                                i, i, tex_remap, i);
+                        }
                     } else if (ps->state->dim_tex[i] == 3) {
                         mstring_append_fmt(vars, "vec4 t%d = textureProj(texSamp%d, vec4(pT%d.xy, 0.0, pT%d.w));\n",
                                            i, i, i, i);