medfall

commit aa63ef9a6ea3e538fe248a0af9dd136b1af57197
parent 764b0daff15d8ab9639bc193e5bf1b6d7a95770d
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Sun Sep 11 15:45:21 +0100

Slightly better terrain shader

Diffstat:
terrain_manager.cc
 | 
48
+++++++++++++++++++++++++++---------------------
1 file changed, 27 insertions(+), 21 deletions(-)
diff --git a/terrain_manager.cc b/terrain_manager.cc
@@ -51,34 +51,39 @@ static const GLchar * frag_src = GLSL(
 
 	void main() {
 		vec3 normal = normalize( texture( normals, smooth_position.xy / dimensions ).xyz );
+		vec3 sun_direction = normalize( vec3( 1, 1, -sun ) );
+		float horizon = texture( horizons, smooth_position.xy / dimensions ).r;
 
+		// ground colour
 		vec3 ground;
-		if( normal.z > 0.9 ) {
-			ground = vec3( 0.4, 1.0, 0.4 );
+		if( smooth_position.z > 175 ) {
+			// snow/rocks
+			if( normal.z > 0.5 ) {
+				ground = vec3( 0.8, 0.8, 0.8 );
+			}
+			else {
+				ground = vec3( 0.6, 0.6, 0.6 );
+			}
 		}
 		else {
-			ground = vec3( 0.7, 0.7, 0.5 );
+			if( normal.z > 0.8 ) {
+				ground = vec3( 0.4, 1.0, 0.4 );
+			}
+			else {
+				ground = vec3( 0.7, 0.7, 0.5 );
+			}
 		}
 
-		vec3 sunv = normalize( vec3( 1, 1, -sun ) );
-		float horizon = texture( horizons, smooth_position.xy / dimensions ).r;
-		float l = sun > horizon ? 1.0 : 0.0;
-
-		float d = max( 0, -dot( normal, sunv ) );
-		float light = max( 0.2, l * d );
-
-		// colour *= 0;
-		// colour = vec4( horizon, horizon, horizon, 1.0 );
+		// sunlight + sky ambient lighting
+		// TODO: use formula for area of a chord?
+		float sun_visible_fraction = smoothstep( 0, 0.5, sun - horizon );
+		float sunlight_lambert = max( 0, -dot( normal, sun_direction ) );
+		vec3 sunlight = sun_visible_fraction * sunlight_lambert * vec3( 0.9, 0.9, 0.5 );
+		vec3 ambient = vec3( 0.0, 0.1, 0.3 );
 
-		// if( smooth_position.y > 10.5 && smooth_position.y < 11.5 ) {
-		// 	colour.r = 1;
-		// }
-                //
-		// int a = int( smooth_position.x ) / 10;
-		// if( a % 2 == 0 ) colour.g = 1;
+		vec3 c = ( sunlight + ambient ) * ground;
 
-		vec3 c = ground * light;
-		// place some lights
+		// lights
 		for( int i = 0; i < 5; i++ ) {
 			vec3 light_position = texelFetch( point_light_origins, i ).xyz;
 			vec3 light_colour = texelFetch( point_light_colours, i ).rgb;
@@ -86,9 +91,10 @@ static const GLchar * frag_src = GLSL(
 			vec3 light_direction = normalize( light_position - smooth_position );
 			float lambert_scale = dot( light_direction, normal );
 			float distance_scale = 1.0 / sqrt( light_sqdistance );
-			c += vec3( light_colour * lambert_scale * distance_scale );
+			c += vec3( light_colour * lambert_scale * distance_scale ) * ground;
 		}
 
+		// fog
 		vec3 fog = vec3( 0.6, 0.6, 0.6 );
 
 		float depth = length( pos );