From b85b8b599473a76e055008a2d45432d02848cb42 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 14 Aug 2012 00:21:05 +0300
Subject: [PATCH] Add a standard program feature for environment-mapped
 reflections

---
 source/program.cpp | 19 ++++++++++++++-----
 source/program.h   |  1 +
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/source/program.cpp b/source/program.cpp
index 749a7d9c..02e0a1b4 100644
--- a/source/program.cpp
+++ b/source/program.cpp
@@ -19,7 +19,7 @@ const char *standard_vertex_src[] =
 	"!lm", "varying vec4 v_color;\n",
 	"l!n", "varying vec3 v_normal;\n",
 	"l",   "varying vec3 v_light_dir;\n",
-	"p",   "varying vec3 v_eye_dir;\n",
+	"p|e", "varying vec3 v_eye_dir;\n",
 	"r",   "vec4 transform_vertex(vec4);\n",
 	"lr",  "vec3 transform_normal(vec3);\n",
 	 0,    "void main()\n",
@@ -35,9 +35,9 @@ const char *standard_vertex_src[] =
 	"l",   "\tvec3 eye_light_dir = normalize(gl_LightSource[0].position.xyz-eye_pos.xyz*gl_LightSource[0].position.w);\n",
 	"n",   "\tv_light_dir = vec3(dot(eye_tangent, eye_light_dir), dot(eye_binormal, eye_light_dir), dot(eye_normal, eye_light_dir));\n",
 	"l!n", "\tv_light_dir = eye_light_dir;\n",
-	"p",   "\tvec3 eye_dir = -normalize(eye_pos.xyz);\n",
-	"pn",  "\tv_eye_dir = vec3(dot(eye_tangent, eye_dir), dot(eye_binormal, eye_dir), dot(eye_normal, eye_dir));\n",
-	"p!n", "\tv_eye_dir = eye_dir;\n",
+	"p|e", "\tvec3 eye_dir = -normalize(eye_pos.xyz);\n",
+	"p|en",  "\tv_eye_dir = vec3(dot(eye_tangent, eye_dir), dot(eye_binormal, eye_dir), dot(eye_normal, eye_dir));\n",
+	"p|e!n", "\tv_eye_dir = eye_dir;\n",
 	"t|n", "\tv_texcoord = gl_MultiTexCoord0.xy;\n",
 	"s",   "\tv_shadowcoord = vec3(dot(gl_EyePlaneS[3], eye_pos), dot(gl_EyePlaneT[3], eye_pos), dot(gl_EyePlaneR[3], eye_pos));\n",
 	"!lm", "\tv_color = gl_Color;\n",
@@ -50,12 +50,14 @@ const char *standard_fragment_src[] =
 	"t",   "uniform sampler2D texture;\n",
 	"n",   "uniform sampler2D normalmap;\n",
 	"s",   "uniform sampler2DShadow shadow;\n",
+	"e",   "uniform samplerCube environment;\n",
+	"e",   "uniform float reflectivity;\n",
 	"t|n", "varying vec2 v_texcoord;\n",
 	"s",   "varying vec3 v_shadowcoord;\n",
 	"!lm", "varying vec4 v_color;\n",
 	"l!n", "varying vec3 v_normal;\n",
 	"l",   "varying vec3 v_light_dir;\n",
-	"p",   "varying vec3 v_eye_dir;\n",
+	"p|e", "varying vec3 v_eye_dir;\n",
 	 0,    "void main()\n",
 	 0,    "{\n",
 	"n",   "\tvec3 n_normal = texture2D(normalmap, v_texcoord).xyz*2.0-1.0;\n",
@@ -64,6 +66,9 @@ const char *standard_fragment_src[] =
 	"p",   "\tvec3 half_dir = normalize(v_eye_dir+v_light_dir);\n",
 	"p",   "\tfloat l_specular = pow(max(dot(half_dir, n_normal), 0.0), gl_FrontMaterial.shininess);\n",
 	"s",   "\tfloat l_shadow = shadow2D(shadow, v_shadowcoord).r;\n",
+	/* XXX This is incorrect with normal mapping, since the vectors are in TBN
+	space but environment map is expected to be in eye space */
+	"e",   "\tvec4 reflection = textureCube(environment, n_normal*(dot(n_normal, v_eye_dir)*2.0)-v_eye_dir);\n",
 	 0,    "\tgl_FragColor = ",
 	"!t!l!m", "vec4(1.0, 1.0, 1.0, 1.0)",
 	"t",     "texture2D(texture, v_texcoord)",
@@ -77,6 +82,7 @@ const char *standard_fragment_src[] =
 	"s",     "*l_shadow",
 	"lm",    "+gl_FrontLightModelProduct.sceneColor",
 	"l",     ")",
+	"e",     "+reflection*reflectivity",
 	 0,      ";\n",
 	 0,    "}\n",
 	0, 0
@@ -296,6 +302,7 @@ Program::StandardFeatures::StandardFeatures():
 	specular(false),
 	normalmap(false),
 	shadow(false),
+	reflection(false),
 	transform(false)
 { }
 
@@ -316,6 +323,8 @@ string Program::StandardFeatures::create_flags() const
 	}
 	if(shadow)
 		flags += 's';
+	if(reflection)
+		flags += 'e';
 	if(transform)
 		flags += 'r';
 
diff --git a/source/program.h b/source/program.h
index ac8e24b5..b6007073 100644
--- a/source/program.h
+++ b/source/program.h
@@ -43,6 +43,7 @@ public:
 		bool specular;
 		bool normalmap;
 		bool shadow;
+		bool reflection;
 		bool transform;
 
 		StandardFeatures();
-- 
2.45.2