From 43593f9e891d607a7de08848295e1afa4802e715 Mon Sep 17 00:00:00 2001
From: Marisa the Magician <marisa@sayachan.org>
Date: Mon, 28 Nov 2022 00:35:12 +0100
Subject: [PATCH] Allow envmask shader to use multiple masks (up to 3).

---
 language.version        |  4 ++--
 shaders/glsl/Envmask.fp | 50 +++++++++++++++++++++++++++++++++++++----
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/language.version b/language.version
index b64724325..99dcd958e 100644
--- a/language.version
+++ b/language.version
@@ -1,3 +1,3 @@
 [default]
-SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r641 \cu(Mon 28 Nov 00:35:00 CET 2022)\c-";
-SWWM_SHORTVER="\cw1.3pre r641 \cu(2022-11-28 00:35:00)\c-";
+SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r642 \cu(Mon 28 Nov 00:35:12 CET 2022)\c-";
+SWWM_SHORTVER="\cw1.3pre r642 \cu(2022-11-28 00:35:12)\c-";
diff --git a/shaders/glsl/Envmask.fp b/shaders/glsl/Envmask.fp
index d5920b996..aedf6af03 100644
--- a/shaders/glsl/Envmask.fp
+++ b/shaders/glsl/Envmask.fp
@@ -1,4 +1,5 @@
 // basic texture + masked equirectangular envmap + gradient rim
+// allows for up to three different layers of environment mapping (RGB mask)
 #define RECIPROCAL_PI2 0.15915494
 
 #ifndef RIMSTEP
@@ -11,22 +12,63 @@
 #define RIMFACT 1.
 #endif
 
+#ifndef RIMSTEP2
+#define RIMSTEP2 .5
+#endif
+#ifndef ENVFACT2
+#define ENVFACT2 1.
+#endif
+#ifndef RIMFACT2
+#define RIMFACT2 1.
+#endif
+
+#ifndef RIMSTEP3
+#define RIMSTEP3 .5
+#endif
+#ifndef ENVFACT3
+#define ENVFACT3 1.
+#endif
+#ifndef RIMFACT3
+#define RIMFACT3 1.
+#endif
+
 void SetupMaterial( inout Material mat )
 {
 	vec4 base = getTexel(vTexCoord.st);
-	float mask = texture(masktex,vTexCoord.st).x;
+	vec4 mask = texture(masktex,vTexCoord.st);
 	vec3 norm = normalize(vWorldNormal.xyz);
 	vec3 eye = normalize(uCameraPos.xyz-pixelpos.xyz);
 	vec3 rvec = normalize(reflect(eye,norm));
 	vec2 uv = vec2(atan(rvec.z,rvec.x)*RECIPROCAL_PI2+.5,asin(rvec.y)*RECIPROCAL_PI2+.5);
 	vec2 uv2 = vec2(atan(rvec.z,abs(rvec.x))*RECIPROCAL_PI2+.5,asin(rvec.y)*RECIPROCAL_PI2+.5);
-	vec3 envcol = textureGrad(envtex,uv,dFdx(uv2),dFdy(uv2)).rgb*ENVFACT;
+	vec2 dTdx = dFdx(uv2);
+	vec2 dTdy = dFdy(uv2);
+	float rf = 1.-abs(dot(eye,norm));
+	vec3 envcol = textureGrad(envtex,uv,dTdx,dTdy).rgb*ENVFACT;
 #ifdef RIM_LIGHTING
-	float rim = smoothstep(RIMSTEP,1.,1.-abs(dot(eye,norm)));
+	float rim = smoothstep(RIMSTEP,1.,rf);
 	vec3 rimcol = texture(rimtex,vec2(.25+.5*rim,.5)).rgb;
 	envcol = mix(envcol,rimcol,rim*RIMFACT);
 #endif
-	mat.Base = vec4(base.rgb+envcol*mask,base.a);
+	mat.Base = vec4(base.rgb+envcol*mask.x,base.a);
+#if defined(ENV_TWOLAYER) || defined(ENV_THREELAYER)
+	envcol = textureGrad(envtex2,uv,dTdx,dTdy).rgb*ENVFACT2;
+#ifdef RIM_LIGHTING
+	rim = smoothstep(RIMSTEP2,1.,rf);
+	rimcol = texture(rimtex2,vec2(.25+.5*rim,.5)).rgb;
+	envcol = mix(envcol,rimcol,rim*RIMFACT2);
+#endif
+	mat.Base.rgb += envcol*mask.y;
+#endif
+#if defined(ENV_THREELAYER)
+	envcol = textureGrad(envtex3,uv,dTdx,dTdy).rgb*ENVFACT3;
+#ifdef RIM_LIGHTING
+	rim = smoothstep(RIMSTEP3,1.,rf);
+	rimcol = texture(rimtex3,vec2(.25+.5*rim,.5)).rgb;
+	envcol = mix(envcol,rimcol,rim*RIMFACT3);
+#endif
+	mat.Base.rgb += envcol*mask.z;
+#endif
 	mat.Normal = ApplyNormalMap(vTexCoord.st);
 	if ( (uTextureMode&TEXF_Brightmap) != 0 )
 		mat.Bright = texture(brighttexture,vTexCoord.st);