medfall

commit 4e909f86b2f4bd19389d5f085227907e60c7d280
parent e14f300f0db9a62046071753bd304286b1be40a8
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Sun Jul  9 15:47:58 +0300

Dumpy sunrise shader

Diffstat:
hm.cc
 | 
2
+-
shaders/skybox.glsl
 | 
50
++++++++++++++++++++++++++++++++++++++++++--------
skybox.cc
 | 
4
++--
skybox.h
 | 
2
+-
4 files changed, 46 insertions(+), 12 deletions(-)
diff --git a/hm.cc b/hm.cc
@@ -198,7 +198,7 @@ GAME_FRAME( game_frame ) {
 	m4 Vsky = m4_view( forward, right, up, v3( 0 ) );
 	v3 sun_dir = v3( -cosf( game->sun_angle ), 0, sinf( game->sun_angle ) );
 
-	skybox_render( &game->skybox, Vsky, P, sun_dir );
+	skybox_render( &game->skybox, Vsky, P, game->sun_angle, sun_dir );
 	terrain_render( &game->tm, V, P, game->sun_angle, sun_dir, current_time );
 
 	struct { m4 V; m4 P; } uniforms = { V, P };
diff --git a/shaders/skybox.glsl b/shaders/skybox.glsl
@@ -20,19 +20,53 @@ out vec4 colour;
 
 layout( std140 ) uniform sun {
 	vec3 sun_dir;
+	float sun_angle;
 };
 
+float asdf( float x, float lo, float hi ) {
+	return clamp( ( x - lo ) / ( hi - lo ), 0.0, 1.0 );
+}
+
+float hdot( vec3 u, vec3 v ) {
+	float d = dot( u, v ) * 0.5 + 0.5;
+	return d * d;
+}
+
 void main() {
-	vec4 horizon = vec4( 0.4, 0.7, 1.0, 1.0 );
-	vec4 top = vec4( 0.3, 0.6, 1.0, 1.0 );
-	vec4 halo = vec4( 0.5, 0.7, 1.0, 1.0 );
-	vec4 sunny = vec4( 0.9, 0.9, 0.2, 1.0 );
+	vec3 npos = normalize( pos );
+
+	vec3 night = vec3( 0.0, 0.0, 0.01 );
+	vec3 horizon = vec3( 0.4, 0.7, 1.0 );
+	vec3 top = vec3( 0.1, 0.4, 0.8 );
+	vec3 sunny = vec3( 1.0, 0.9, 0.8 );
+
+	float elevation = 0.0;
+	if( abs( npos.z ) > 0.001 ) {
+		float cos_elevation = dot( npos.xy, npos.xy ) / ( length( npos.xy ) );
+		elevation = acos( cos_elevation );
+	}
+
+	float sun_dot = clamp( dot( sun_dir, npos ), 0.0, 1.0 );
+	float sun_intensity = smoothstep( 0.995, 1.0, sun_dot );
+	float halo_intensity = smoothstep( 0.90, 1.0, sun_dot );
+
+	float scaled_z = elevation / 1.571;
+	vec3 day_colour = mix( horizon, top, scaled_z );
+
+	vec3 dawn = vec3( 1.0, 0.35, 0.0 );
+
+	float night_sun_angle = -0.4;
+	float dawn_sun_angle = 0.0;
+	float day_sun_angle = 1.0;
+
+	float night_to_dawn = asdf( sun_angle, night_sun_angle, dawn_sun_angle );
+	float dawn_to_day = asdf( sun_angle, dawn_sun_angle, day_sun_angle );
+	day_colour += vec3( 0.5, 0.2, 0.0 ) * halo_intensity * 0.5 * dawn_to_day;
 
-	float scaled_z = smoothstep( 0.0, 0.2, pos.z );
-	float sun_dot = smoothstep( 0.995, 1.0, dot( sun_dir, normalize( pos ) ) );
-	float halo_dot = smoothstep( 0.90, 1.0, dot( sun_dir, normalize( pos ) ) );
+	vec3 night_colour = mix( night, sunny, sun_intensity );
 
-	colour = mix( mix( mix( horizon, top, scaled_z ), halo, halo_dot ), sunny, sun_dot );
+	colour = vec4( mix( mix( night_colour, dawn * hdot( npos, sun_dir ), night_to_dawn ), day_colour, dawn_to_day ), 1.0 );
+	colour = mix( colour, vec4( sunny, 1.0 ), sun_intensity );
 }
 
 #endif
diff --git a/skybox.cc b/skybox.cc
@@ -41,9 +41,9 @@ static m4 angles_to_view( v3 angles ) {
 	return m4_rotz( -angles.y ) * m4_rotx( -angles.x );
 }
 
-void skybox_render( const Skybox * skybox, const m4 & V, const m4 & P, v3 sun_dir ) {
+void skybox_render( const Skybox * skybox, const m4 & V, const m4 & P, float sun_angle, v3 sun_dir ) {
 	renderer_ub_easy( skybox->ub_view, V, P );
-	renderer_ub_easy( skybox->ub_sun, sun_dir );
+	renderer_ub_easy( skybox->ub_sun, sun_dir, sun_angle );
 
 	RenderState render_state;
 	render_state.shader = get_shader( SHADER_SKYBOX );
diff --git a/skybox.h b/skybox.h
@@ -10,5 +10,5 @@ struct Skybox {
 };
 
 void skybox_init( Skybox * skybox );
-void skybox_render( const Skybox * skybox, const m4 & V, const m4 & P, v3 sun_dir );
+void skybox_render( const Skybox * skybox, const m4 & V, const m4 & P, float sun_angle, v3 sun_dir );
 void skybox_destroy( Skybox * skybox );