Illumination mapping of the dark side of custom planets is now suppor…

…ted on the diffuse map's alpha channel. If the alpha channel is used in the diffuse map, low values correspond to high illumination.

Resources/Config/material-defaults.plist

@@ -55,26 +55,30 @@
 	{
 		IS_OOLITE = 1;
 		OOSTD_DIFFUSE_MAP = 1;
+		OOSTD_DIFFUSE_AND_ILLUMINATION_MAP = 1;
 		OOSTD_CUBE_MAP = 0;
 	};
 	"moon-customized-macros" =
 	{
 		IS_OOLITE = 1;
 		OOSTD_DIFFUSE_MAP = 1;
+		OOSTD_DIFFUSE_AND_ILLUMINATION_MAP = 1;
 		OOSTD_CUBE_MAP = 0;
 		OOSTD_HARSH_MISTRESS = 1;
 	};
 	"planet-customized-normspec-macros" =
 	{
 		IS_OOLITE = 1;
 		OOSTD_DIFFUSE_MAP = 1;
+		OOSTD_DIFFUSE_AND_ILLUMINATION_MAP = 1;
 		OOSTD_CUBE_MAP = 0;
 		OOSTD_NORMAL_AND_SPECULAR_MAP = 1;
 	};
 	"moon-customized-normspec-macros" =
 	{
 		IS_OOLITE = 1;
 		OOSTD_DIFFUSE_MAP = 1;
+		OOSTD_DIFFUSE_AND_ILLUMINATION_MAP = 1;
 		OOSTD_CUBE_MAP = 0;
 		OOSTD_HARSH_MISTRESS = 1;
 		OOSTD_NORMAL_AND_SPECULAR_MAP = 1;
@@ -83,26 +87,30 @@
 	{
 		IS_OOLITE = 1;
 		OOSTD_DIFFUSE_MAP = 1;
+		OOSTD_DIFFUSE_AND_ILLUMINATION_MAP = 1;
 		OOSTD_CUBE_MAP = 1;
 	};
 	"moon-customized-cubemap-macros" =
 	{
 		IS_OOLITE = 1;
 		OOSTD_DIFFUSE_MAP = 1;
+		OOSTD_DIFFUSE_AND_ILLUMINATION_MAP = 1;
 		OOSTD_CUBE_MAP = 1;
 		OOSTD_HARSH_MISTRESS = 1;
 	};
 	"planet-customized-cubemap-normspec-macros" =
 	{
 		IS_OOLITE = 1;
 		OOSTD_DIFFUSE_MAP = 1;
+		OOSTD_DIFFUSE_AND_ILLUMINATION_MAP = 1;
 		OOSTD_CUBE_MAP = 1;
 		OOSTD_NORMAL_AND_SPECULAR_MAP = 1;
 	};
 	"moon-customized-cubemap-normspec-macros" =
 	{
 		IS_OOLITE = 1;
 		OOSTD_DIFFUSE_MAP = 1;
+		OOSTD_DIFFUSE_AND_ILLUMINATION_MAP = 1;
 		OOSTD_CUBE_MAP = 1;
 		OOSTD_HARSH_MISTRESS = 1;
 		OOSTD_NORMAL_AND_SPECULAR_MAP = 1;

Resources/Shaders/oolite-default-planet.fragment

@@ -68,7 +68,9 @@
 uniform sampler2D		uIlluminationMap;
 #define ILLUMINATION_COLOR texture2D(uIlluminationMap, texCoords).rgb
 #elif OOSTD_DIFFUSE_AND_ILLUMINATION_MAP
-#define ILLUMINATION_COLOR (diffuseMapSample.a * vec3(0.8, 0.8, 0.4))
+// low alpha values correspond to high illumination, so that textures with unused alpha channel
+// (i.e. alpha == 1.0 for all pixels) display correctly without any illumination
+#define ILLUMINATION_COLOR ((1.0 - diffuseMapSample.a) * vec3(0.8, 0.8, 0.4))
 #endif
 
 
@@ -319,14 +321,14 @@ void main()
 
 	// conservation of energy
 	totalColor += diffuseColor * diffuseLight * (vec3(1.0) - fresnel);
+
+	// paint the orange-reddish terminator
+	totalColor *= diffuseIntensity;
 
 #if USE_ILLUMINATION
 	vec3 illuminationColor = ILLUMINATION_COLOR;
 	totalColor += (1.0 - diffuseIntensity.r) * illuminationColor;
 #endif
-
-	// paint the orange-reddish terminator
-	totalColor *= diffuseIntensity;
 
 	// Ambient light, biased towards blue.
 	vec3 ambientColor = diffuseColor;