From 3d69003c5f50edf61ac4990d6f9d234a76d6a84f Mon Sep 17 00:00:00 2001
From: Luke Benstead <kazade@gmail.com>
Date: Mon, 13 Jun 2022 20:16:37 +0100
Subject: [PATCH] Allow disabling near-z

---
 GL/platforms/sh4.c      | 16 ++++++++++++++++
 GL/platforms/software.c | 13 +++++++++++++
 GL/private.h            |  5 ++---
 GL/state.c              |  6 ++++--
 4 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/GL/platforms/sh4.c b/GL/platforms/sh4.c
index 9c63a0d..f18bdc2 100644
--- a/GL/platforms/sh4.c
+++ b/GL/platforms/sh4.c
@@ -188,6 +188,22 @@ void SceneListSubmit(void* src, int n) {
 
     const float h = GetVideoMode()->height;
 
+    if(!ZNEAR_CLIPPING_ENABLED) {
+        for(int i = 0; i < n; ++i, ++vertex) {
+            PREFETCH(vertex + 1);
+            if(glIsVertex(vertex->flags)) {
+                _glPerspectiveDivideVertex(vertex, h);
+            }
+            _glSubmitHeaderOrVertex(vertex);
+        }
+
+        /* Wait for both store queues to complete */
+        d = (uint32_t *)0xe0000000;
+        d[0] = d[8] = 0;
+
+        return;
+    }
+
     tri_count = 0;
     strip_count = 0;
 
diff --git a/GL/platforms/software.c b/GL/platforms/software.c
index a6f1974..94916a7 100644
--- a/GL/platforms/software.c
+++ b/GL/platforms/software.c
@@ -260,6 +260,19 @@ void SceneListSubmit(void* src, int n) {
 
     const float h = GetVideoMode()->height;
 
+    /* If Z-clipping is disabled, just fire everything over to the buffer */
+    if(!ZNEAR_CLIPPING_ENABLED) {
+        for(int i = 0; i < n; ++i, ++vertex) {
+            PREFETCH(vertex + 1);
+            if(glIsVertex(vertex->flags)) {
+                _glPerspectiveDivideVertex(vertex, h);
+            }
+            _glSubmitHeaderOrVertex(vertex);
+        }
+
+        return;
+    }
+
     tri_count = 0;
     strip_count = 0;
 
diff --git a/GL/private.h b/GL/private.h
index 46287dd..ba286d1 100644
--- a/GL/private.h
+++ b/GL/private.h
@@ -279,9 +279,6 @@ typedef enum {
 
 struct SubmissionTarget;
 
-float _glClipLineToNearZ(const Vertex* v1, const Vertex* v2, Vertex* vout);
-void _glClipTriangleStrip(SubmissionTarget* target, uint8_t fladeShade);
-
 PolyList* _glOpaquePolyList();
 PolyList* _glPunchThruPolyList();
 PolyList *_glTransparentPolyList();
@@ -385,6 +382,8 @@ GLboolean _glIsMipmapComplete(const TextureObject* obj);
 GLubyte* _glGetMipmapLocation(const TextureObject* obj, GLuint level);
 GLuint _glGetMipmapLevelCount(const TextureObject* obj);
 
+extern GLboolean ZNEAR_CLIPPING_ENABLED;
+
 extern GLboolean LIGHTING_ENABLED;
 GLboolean _glIsLightingEnabled();
 
diff --git a/GL/state.c b/GL/state.c
index 5cf1fae..20f28c5 100644
--- a/GL/state.c
+++ b/GL/state.c
@@ -18,6 +18,8 @@ static GLenum FRONT_FACE = GL_CCW;
 static GLboolean CULLING_ENABLED = GL_FALSE;
 static GLboolean COLOR_MATERIAL_ENABLED = GL_FALSE;
 
+GLboolean ZNEAR_CLIPPING_ENABLED = GL_TRUE;
+
 GLboolean LIGHTING_ENABLED = GL_FALSE;
 
 /* Is the shared texture palette enabled? */
@@ -356,7 +358,7 @@ GLAPI void APIENTRY glEnable(GLenum cap) {
             _glEnableLight(cap & 0xF, GL_TRUE);
         break;
         case GL_NEARZ_CLIPPING_KOS:
-            _glEnableClipping(GL_TRUE);
+            ZNEAR_CLIPPING_ENABLED = GL_TRUE;
         break;
         case GL_POLYGON_OFFSET_POINT:
         case GL_POLYGON_OFFSET_LINE:
@@ -418,7 +420,7 @@ GLAPI void APIENTRY glDisable(GLenum cap) {
             _glEnableLight(cap & 0xF, GL_FALSE);
         break;
         case GL_NEARZ_CLIPPING_KOS:
-            _glEnableClipping(GL_FALSE);
+            ZNEAR_CLIPPING_ENABLED = GL_FALSE;
         break;
         case GL_POLYGON_OFFSET_POINT:
         case GL_POLYGON_OFFSET_LINE: