medfall

commit d6ef807a5a3c4ff0b3cd4c79420af4b79fc3b344
parent 35da5c7ee43fe692f087b3f9679009ba3dc0dc2a
Author: Michael Savage <mikejsavage@gmail.com>
Date:   Sat, 25 Nov 2017 22:02:14 +0200

Add functions for exact 90/180/270 degree Z rotations

Diffstat:
clipmap.cc
 | 
7
+++----
linear_algebra.h
 | 
27
+++++++++++++++++++++++++++

2 files changed, 30 insertions(+), 4 deletions(-)
diff --git a/clipmap.cc b/clipmap.cc
@@ -748,12 +748,11 @@ GAME_FRAME( game_frame ) {
 	UniformBinding inf_view_uniforms = renderer_uniforms( V, Pinf, game->pos );
 	UniformBinding sun_uniforms = renderer_uniforms( sun_dir, game->sun_angle );
 
-	// TODO: these need to be exact or there could be cracks in the terrain
 	StaticArray< UniformBinding, 4 > rotation_uniforms;
 	rotation_uniforms[ 0 ] = renderer_uniforms( m4_identity() );
-	rotation_uniforms[ 1 ] = renderer_uniforms( m4_rotz( deg_to_rad( 270 ) ) );
-	rotation_uniforms[ 2 ] = renderer_uniforms( m4_rotz( deg_to_rad( 90 ) ) );
-	rotation_uniforms[ 3 ] = renderer_uniforms( m4_rotz( deg_to_rad( 180 ) ) );
+	rotation_uniforms[ 1 ] = renderer_uniforms( m4_rotz270() );
+	rotation_uniforms[ 2 ] = renderer_uniforms( m4_rotz90() );
+	rotation_uniforms[ 3 ] = renderer_uniforms( m4_rotz180() );
 
 	// draw terrain
 	{
diff --git a/linear_algebra.h b/linear_algebra.h
@@ -732,6 +732,33 @@ forceinline m4 m4_rotz( float theta ) {
 	);
 }
 
+forceinline m4 m4_rotz90() {
+	return m4(
+		0, -1, 0, 0,
+		1, 0, 0, 0,
+		0, 0, 1, 0,
+		0, 0, 0, 1
+	);
+}
+
+forceinline m4 m4_rotz180() {
+	return m4(
+		-1, 0, 0, 0,
+		0, -1, 0, 0,
+		0, 0, 1, 0,
+		0, 0, 0, 1
+	);
+}
+
+forceinline m4 m4_rotz270() {
+	return m4(
+		0, 1, 0, 0,
+		-1, 0, 0, 0,
+		0, 0, 1, 0,
+		0, 0, 0, 1
+	);
+}
+
 forceinline m4 m4_translation( float x, float y, float z ) {
 	return m4(
 		1, 0, 0, x,