From 977fa6e0429a9e9702ab47865fabc640a49b996c Mon Sep 17 00:00:00 2001
From: XProger <xproger@list.ru>
Date: Mon, 25 Jan 2021 18:04:06 +0300
Subject: [PATCH] fix shadow sampling for GL3

---
 src/gapi/gl.h            | 7 ++++---
 src/shaders/compose.glsl | 6 +-----
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/src/gapi/gl.h b/src/gapi/gl.h
index e48a944..befbd5f 100644
--- a/src/gapi/gl.h
+++ b/src/gapi/gl.h
@@ -1381,7 +1381,6 @@ namespace GAPI {
             if (!GLES3) {
                 strcat(extHeader, "#extension GL_EXT_shadow_samplers : enable\n");
             }
-            strcat(extHeader, "#define USE_GL_EXT_shadow_samplers\n");
         }
         
     #ifdef _GAPI_GLES
@@ -1405,7 +1404,7 @@ namespace GAPI {
                                      "#define texture2D   texture\n"
                                      "#define texture3D   texture\n"
                                      "#define textureCube texture\n"
-                                     "#define shadow2DEXT texture\n"
+                                     "#define FETCH_SHADOW2D(a,b) texture(a,b)\n"
                                      "out vec4 fragColor;\n");
         } else {
             // vertex
@@ -1419,6 +1418,7 @@ namespace GAPI {
             strcat(GLSL_HEADER_FRAG, "precision lowp  int;\n"
                                      "precision highp float;\n"
                                      "#define FRAGMENT\n"
+                                     "#define FETCH_SHADOW2D(a,b) shadow2DEXT(a,b)\n"
                                      "#define fragColor gl_FragColor\n");
         }
 
@@ -1440,7 +1440,7 @@ namespace GAPI {
                                      "#define texture2D   texture\n"
                                      "#define texture3D   texture\n"
                                      "#define textureCube texture\n"
-                                     "#define shadow2D    texture\n"
+                                     "#define FETCH_SHADOW2D(a,b) texture(a,b)\n"
                                      "out vec4 fragColor;\n");
         } else {
             // vertex
@@ -1450,6 +1450,7 @@ namespace GAPI {
             strcat(GLSL_HEADER_FRAG, "#version 110\n");
             strcat(GLSL_HEADER_FRAG, extHeader);
             strcat(GLSL_HEADER_FRAG, "#define FRAGMENT\n"
+                                     "#define FETCH_SHADOW2D(a,b) shadow2D(a,b).x\n"
                                      "#define fragColor gl_FragColor\n");
         }
     #endif
diff --git a/src/shaders/compose.glsl b/src/shaders/compose.glsl
index 4a47b76..76fd0cd 100644
--- a/src/shaders/compose.glsl
+++ b/src/shaders/compose.glsl
@@ -262,11 +262,7 @@ varying vec4 vTexCoord; // xy - atlas coords, zw - trapezoidal correction
 	#ifdef OPT_SHADOW
 		#ifdef SHADOW_SAMPLER
 			uniform sampler2DShadow sShadow;
-			#ifdef USE_GL_EXT_shadow_samplers
-				#define SHADOW(V) (shadow2DEXT(sShadow, V))
-			#else
-				#define SHADOW(V) (shadow2D(sShadow, V).x)
-			#endif
+			#define SHADOW(p) (FETCH_SHADOW2D(sShadow, p))
 		#else
 			uniform sampler2D sShadow;