Preserve Vulkan wide overlay row clipping

runtime/include/gpu_render.h

@@ -53,9 +53,9 @@ void gr_set_precise_triangle(int enabled,
 /* Perspective-correct UV weights for the NEXT triangle ([video]
  * perspective_texturing). q[i] is the normalized 1/z homogeneous weight at
  * vertex i. enabled == 0 restores the PS1's affine UV interpolation. */
+void gr_set_perspective_triangle(int enabled, float q0, float q1, float q2);
 /* Original perspective-qualified triangles since process startup. */
 uint32_t gr_perspective_triangle_count(void);
-void gr_set_perspective_triangle(int enabled, float q0, float q1, float q2);
 
 /* Primitives */
 void gr_fill_rect(int x, int y, int w, int h, uint16_t color);

runtime/src/gpu_vk_renderer.c

@@ -2790,8 +2790,8 @@ static void vkb_draw_gouraud_triangle(int x0,int y0,uint16_t c0,int x1,int y1,ui
 /* Full-screen-overlay wide pass (pause gray-filter / load fade): draw a flat
  * rect covering the FULL wide width [0, wide_w) x [y, y+h) directly into the
  * active wide surface (positions already wide-space, u_xoff = 0). Mirrors GL's
- * wide_flat_rect_direct: full-surface scissor (the overlay must dim the
- * revealed margins too). The 6 verts are consumed privately (s_vbase bumped)
+ * wide_flat_rect_direct: full-width scissor (the overlay must dim the
+ * revealed margins too), while preserving the draw-area Y band. The 6 verts are consumed privately (s_vbase bumped)
  * so they never join a canonical batch. */
 static void wide_overlay_rect(int y, int h, uint16_t c, int semi) {
     if (s_wide_cur < 0 || !s_ready) return;
@@ -2803,12 +2803,9 @@ static void wide_overlay_rect(int y, int h, uint16_t c, int semi) {
     push_vert(x0, fy0, col); push_vert(x1, fy1, col); push_vert(x0, fy1, col);
     s_vbase += s_vcount; s_vcount = 0;    /* consume privately */
     int blend = (semi < 0) ? 0 : (semi + 1);
-    int S = s_scale;
     VkCommandBuffer cb = begin_oneshot();
+    /* Keep the full width and current Y clip, including interlaced row clips. */
     wide_pass_begin(cb);
-    /* Overlay covers the whole surface: override the band scissor. */
-    VkRect2D sc = { { 0, 0 }, { (uint32_t)(s_wide_w * S), (uint32_t)(VRAM_H * S) } };
-    p_vkCmdSetScissor(cb, 0, 1, &sc);
     bind_masked(cb, 0, 0, blend, s_mask_check, s_mask_set);
     GeoPush gp = { px_shift(), 0.0f, (float)s_wide_w / 2.0f };
     p_vkCmdPushConstants(cb, s_pl_geo, VK_SHADER_STAGE_VERTEX_BIT, 0, sizeof gp, &gp);

runtime/tests/test_gpu_interlace_render.c

@@ -131,10 +131,13 @@ int main(void) {
             gr_set_perspective_triangle(1,1.0f,0.5f,0.25f);
             gr_draw_textured_triangle(2,2,0,0,10,2,8,0,2,10,0,8,0,0,0x104);
             CHECK(gr_perspective_triangle_count() == before + 1);
+            gr_set_perspective_triangle(1,0.5f,0.25f,0.125f);
+            gr_draw_textured_triangle(2,2,0,0,10,2,8,0,2,10,0,8,0,0,0x104);
+            CHECK(gr_perspective_triangle_count() == before + 2);
             gr_set_perspective_triangle(0,1.0f,1.0f,1.0f);
             gr_set_perspective_triangle(1,0.0f,1.0f,1.0f);
             gr_draw_textured_triangle(2,2,0,0,10,2,8,0,2,10,0,8,0,0,0x104);
-            CHECK(gr_perspective_triangle_count() == before + 1);
+            CHECK(gr_perspective_triangle_count() == before + 2);
         }
     }
     /* A single enhanced triangle keeps its metadata through all row clips. */

runtime/tests/test_vk_draw_area_batch_boundary.py

@@ -1,9 +1,11 @@
 #!/usr/bin/env python3
 from pathlib import Path
 import re
+import sys
 
 
-source = (Path(__file__).parents[1] / "src" / "gpu_vk_renderer.c").read_text()
+source_path = Path(sys.argv[1]) if len(sys.argv) > 1 else Path(__file__).parents[1] / "src" / "gpu_vk_renderer.c"
+source = source_path.read_text(encoding="utf-8")
 setter = re.search(
     r"static void vkb_set_draw_area\(.*?\n\}", source, flags=re.DOTALL
 )
@@ -21,3 +23,14 @@ assert tex_flush < state_write and geo_flush < state_write, (
 )
 
 print("Vulkan draw-area batch-boundary test passed")
+
+# Native-wide overlays must retain the same vertical clip as other geometry.
+# This source guard is not a substitute for Vulkan driver/pixel qualification.
+wide = re.search(r"static void wide_pass_begin\(.*?\n\}", source, flags=re.DOTALL)
+overlay = re.search(r"static void wide_overlay_rect\(.*?\n\}", source, flags=re.DOTALL)
+assert wide and overlay, "wide render helpers not found"
+assert "s_da_y1" in wide[0] and "s_da_y2" in wide[0]
+assert "p_vkCmdSetScissor" in wide[0]
+assert "wide_pass_begin(cb);" in overlay[0]
+assert "p_vkCmdSetScissor" not in overlay[0], "overlay overrides the draw-area Y clip"
+print("Vulkan wide-overlay clip source guard passed")