From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 19 Aug 2012 00:34:22 +0000 (+0300)
Subject: Lighting affecting the alpha value of a surface makes no sense
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=101b961cbdcc3a2459bb7c12e3d8e6e5c320b94b

Lighting affecting the alpha value of a surface makes no sense

Use lighting only for RGB components, and take alpha directly from color
or material.  This should prevent problems caused by alpha>1.
---

diff --git a/source/program.cpp b/source/program.cpp
index 587a3fb0..7598bf15 100644
--- a/source/program.cpp
+++ b/source/program.cpp
@@ -73,20 +73,27 @@ const char *standard_fragment_src[] =
 	/* 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)",
+	"t",   "\tvec4 tex_sample = texture2D(texture, v_texcoord);\n",
+	 0,    "\tgl_FragColor.rgb = ",
+	"!t!l!m", "vec3(1.0)",
+	"t",     "tex_sample.rgb",
 	"l|mt",  "*",
-	"!lm",   "v_color",
+	"!lm",   "v_color.rgb",
 	"l",     "((l_diffuse",
-	"lm",    "*gl_FrontLightProduct[0].diffuse",
+	"lm",    "*gl_FrontLightProduct[0].diffuse.rgb",
 	"p",     "+l_specular",
-	"pm",    "*gl_FrontLightProduct[0].specular",
+	"pm",    "*gl_FrontLightProduct[0].specular.rgb",
 	"l",     ")",
 	"s",     "*l_shadow",
-	"lm",    "+gl_FrontLightModelProduct.sceneColor",
+	"lm",    "+gl_FrontLightModelProduct.sceneColor.rgb",
 	"l",     ")",
-	"e",     "+reflection*reflectivity",
+	"e",     "+reflection.rgb*reflectivity",
+	 0,      ";\n",
+	 0,    "\tgl_FragColor.a = ",
+	"!m",    "1.0",
+	"!lm",   "v_color.a",
+	"lm",    "gl_FrontMaterial.diffuse.a",
+	"t",     "*tex_sample.a",
 	 0,      ";\n",
 	 0,    "}\n",
 	0, 0