From 462b64b8ce26632d08556d616fbe7607d59ed609 Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Sun, 11 Feb 2024 19:21:22 +0300
Subject: [PATCH] ref: gl: add water warp scroll effect for compatibility with
 Magic-Nipples's engine fork

---
 ref/gl/gl_local.h  |  3 +++
 ref/gl/gl_opengl.c |  6 ++++++
 ref/gl/gl_warp.c   | 28 +++++++++++++++++++++-------
 3 files changed, 30 insertions(+), 7 deletions(-)

diff --git a/ref/gl/gl_local.h b/ref/gl/gl_local.h
index 35c98797..15bd237a 100644
--- a/ref/gl/gl_local.h
+++ b/ref/gl/gl_local.h
@@ -809,6 +809,9 @@ extern convar_t r_studio_drawelements;
 extern convar_t r_ripple;
 extern convar_t r_ripple_updatetime;
 extern convar_t r_ripple_spawntime;
+extern convar_t r_water_warp;
+extern convar_t r_water_warp_x;
+extern convar_t r_water_warp_y;
 
 //
 // engine shared convars
diff --git a/ref/gl/gl_opengl.c b/ref/gl/gl_opengl.c
index d0be3cd1..8b4e65bf 100644
--- a/ref/gl/gl_opengl.c
+++ b/ref/gl/gl_opengl.c
@@ -37,6 +37,9 @@ CVAR_DEFINE( r_vbo_overbrightmode, "gl_vbo_overbrightmode", "0", FCVAR_ARCHIVE,
 CVAR_DEFINE_AUTO( r_ripple, "0", FCVAR_GLCONFIG, "enable software-like water texture ripple simulation" );
 CVAR_DEFINE_AUTO( r_ripple_updatetime, "0.05", FCVAR_GLCONFIG, "how fast ripple simulation is" );
 CVAR_DEFINE_AUTO( r_ripple_spawntime, "0.1", FCVAR_GLCONFIG, "how fast new ripples spawn" );
+CVAR_DEFINE_AUTO( r_water_warp, "1", FCVAR_GLCONFIG, "set water warp style (0: disable, 1: sine waves, 2: constant scroll)" );
+CVAR_DEFINE_AUTO( r_water_warp_x, "6", FCVAR_GLCONFIG, "water warp scroll x axis speed" );
+CVAR_DEFINE_AUTO( r_water_warp_y, "6", FCVAR_GLCONFIG, "water warp scroll y axis speed" );
 
 
 DEFINE_ENGINE_SHARED_CVAR_LIST()
@@ -1192,6 +1195,9 @@ static void GL_InitCommands( void )
 	gEngfuncs.Cvar_RegisterVariable( &r_ripple );
 	gEngfuncs.Cvar_RegisterVariable( &r_ripple_updatetime );
 	gEngfuncs.Cvar_RegisterVariable( &r_ripple_spawntime );
+	gEngfuncs.Cvar_RegisterVariable( &r_water_warp );
+	gEngfuncs.Cvar_RegisterVariable( &r_water_warp_x );
+	gEngfuncs.Cvar_RegisterVariable( &r_water_warp_y );
 
 	gEngfuncs.Cvar_RegisterVariable( &gl_extensions );
 	gEngfuncs.Cvar_RegisterVariable( &gl_texture_nearest );
diff --git a/ref/gl/gl_warp.c b/ref/gl/gl_warp.c
index bff62d6e..5e2e58f2 100644
--- a/ref/gl/gl_warp.c
+++ b/ref/gl/gl_warp.c
@@ -781,7 +781,7 @@ Does a water warp on the pre-fragmented glpoly_t chain
 void EmitWaterPolys( msurface_t *warp, qboolean reverse )
 {
 	float	*v, nv, waveHeight;
-	float	s, t, os, ot;
+	float	s, t, os, ot, warp_s, warp_t;
 	glpoly_t	*p;
 	int	i;
 
@@ -822,15 +822,29 @@ void EmitWaterPolys( msurface_t *warp, qboolean reverse )
 			os = v[3];
 			ot = v[4];
 
-			if( !r_ripple.value )
+			switch((int)r_water_warp.value )
 			{
-				s = os + r_turbsin[(int)((ot * 0.125f + gp_cl->time) * TURBSCALE) & 255];
-				t = ot + r_turbsin[(int)((os * 0.125f + gp_cl->time) * TURBSCALE) & 255];
+			case 0:
+				warp_s = warp_t = 0;
+				break;
+			case 1:
+				warp_s = r_turbsin[(int)((ot * 0.125f + gp_cl->time) * TURBSCALE) & 255];
+				warp_t = r_turbsin[(int)((os * 0.125f + gp_cl->time) * TURBSCALE) & 255];
+				break;
+			case 2:
+			default:
+				warp_s = gp_cl->time * r_water_warp_x.value;
+				warp_t = gp_cl->time * r_water_warp_y.value;
+				break;
 			}
-			else
+
+			s = os + warp_s;
+			t = ot + warp_t;
+
+			if( r_ripple.value )
 			{
-				s = os / g_ripple.texturescale;
-				t = ot / g_ripple.texturescale;
+				s /= g_ripple.texturescale;
+				t /= g_ripple.texturescale;
 			}
 
 			s *= ( 1.0f / SUBDIVIDE_SIZE );