medfall

commit 95f11e8fe66a4ae6927efd394793067723f43abf
parent f0daff30dd4d58974265c9f1b89201fcba894107
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Sat, 11 Nov 2017 21:14:25 +0200

Draw skybox last to reduce overdraw

Diffstat:
clipmap.cc
 | 
6
++++--
linear_algebra.h
 | 
27
+++++++++++++++++++++++++++
shaders/skybox.glsl
 | 
2
+-
skybox.cc
 | 
1
-

4 files changed, 32 insertions(+), 4 deletions(-)
diff --git a/clipmap.cc b/clipmap.cc
@@ -436,6 +436,7 @@ GAME_FRAME( game_frame ) {
 
 	v3 eye_pos = game->pos + v3( 0, 0, EYE_HEIGHT );
 	m4 P = m4_perspective( VERTICAL_FOV, get_aspect_ratio(), NEAR_PLANE_DEPTH, FAR_PLANE_DEPTH );
+	m4 Pinf = m4_perspective_inf( VERTICAL_FOV, get_aspect_ratio(), NEAR_PLANE_DEPTH );
 	m4 V = m4_view( forward, right, up, eye_pos );
 	m4 Vsky = m4_view( forward, right, up, v3( 0 ) );
 	v3 sun_dir = v3( -cosf( game->sun_angle ), 0, sinf( game->sun_angle ) );
@@ -443,9 +444,8 @@ GAME_FRAME( game_frame ) {
 	renderer_begin_frame();
 	renderer_begin_pass( RENDERER_CLEAR_COLOUR_DO, RENDERER_CLEAR_DEPTH_DO );
 
-	skybox_render( &game->skybox, Vsky, P, game->sun_angle, sun_dir );
-
 	UniformBinding view_uniforms = renderer_uniforms( V, P, game->pos );
+	UniformBinding inf_view_uniforms = renderer_uniforms( V, Pinf, game->pos );
 	UniformBinding sun_uniforms = renderer_uniforms( sun_dir, game->sun_angle );
 
 	// draw terrain
@@ -585,6 +585,8 @@ GAME_FRAME( game_frame ) {
 		immediate_render( explosion_render_state );
 	}
 
+	skybox_render( &game->skybox, Vsky, Pinf, game->sun_angle, sun_dir );
+
 	// networking
 	{
 		char buf[ 1400 ];
diff --git a/linear_algebra.h b/linear_algebra.h
@@ -783,6 +783,33 @@ forceinline m4 m4_perspective( float vertical_fov_degrees, float aspect_ratio, f
 	);
 }
 
+forceinline m4 m4_perspective_inf( float vertical_fov_degrees, float aspect_ratio, float near_plane ) {
+	float tan_half_vertical_fov = tanf( deg_to_rad( vertical_fov_degrees ) / 2.0f );
+	float epsilon = 2.4e-6;
+
+	return m4(
+		1.0f / ( tan_half_vertical_fov * aspect_ratio ),
+		0.0f,
+		0.0f,
+		0.0f,
+
+		0.0f,
+		1.0f / tan_half_vertical_fov,
+		0.0f,
+		0.0f,
+
+		0.0f,
+		0.0f,
+		epsilon - 1.0f,
+		( epsilon - 2.0f ) * near_plane,
+
+		0.0f,
+		0.0f,
+		-1.0f,
+		0.0f
+	);
+}
+
 forceinline m4 operator*( const m4 & lhs, const m4 & rhs ) {
 	return m4(
 		dot( lhs.row0(), rhs.col0 ),
diff --git a/shaders/skybox.glsl b/shaders/skybox.glsl
@@ -9,7 +9,7 @@ layout( std140 ) uniform view {
 };
 
 void main() {
-	gl_Position = P * V * vec4( position, 1.0 );
+	gl_Position = P * V * vec4( position, 0.0 );
 	pos = position;
 }
 
diff --git a/skybox.cc b/skybox.cc
@@ -134,7 +134,6 @@ void skybox_render( const Skybox * skybox, const m4 & Vsky, const m4 & P, float 
 
 	RenderState render_state;
 	render_state.shader = get_shader( SHADER_SKYBOX );
-	render_state.disable_depth_writes = true;
 	render_state.uniforms[ UNIFORMS_VIEW ] = renderer_uniforms( Vsky, P );
 	render_state.uniforms[ UNIFORMS_SKY ] = renderer_uniforms( hosek.A, hosek.B, hosek.C, hosek.D, hosek.E, hosek.F, hosek.G, hosek.H, hosek.I, hosek.Z, sun_dir );
 	render_state.textures[ 0 ] = renderer_blue_noise();