vkquake_yshear.diff

diff --git a/Quake/gl_rmain.c b/Quake/gl_rmain.c
index 7095aa3..b36cc34 100644
--- a/Quake/gl_rmain.c
+++ b/Quake/gl_rmain.c
@@ -22,6 +22,7 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 // r_main.c
 
 #include "quakedef.h"
+#define YSHEAR 1
 
 qboolean	r_cache_thrash;		// compatability
 
@@ -292,8 +293,6 @@ void R_SetupMatrix (void)
 	MatrixMultiply(vulkan_globals.view_matrix, rotation_matrix);
 	RotationMatrix(rotation_matrix, DEG2RAD(-r_refdef.viewangles[2]), 1.0f, 0.0f, 0.0f);
 	MatrixMultiply(vulkan_globals.view_matrix, rotation_matrix);
-	RotationMatrix(rotation_matrix, DEG2RAD(-r_refdef.viewangles[0]), 0.0f, 1.0f, 0.0f);
-	MatrixMultiply(vulkan_globals.view_matrix, rotation_matrix);
 	RotationMatrix(rotation_matrix, DEG2RAD(-r_refdef.viewangles[1]), 0.0f, 0.0f, 1.0f);
 	MatrixMultiply(vulkan_globals.view_matrix, rotation_matrix);
 	
@@ -301,6 +300,15 @@ void R_SetupMatrix (void)
 	TranslationMatrix(translation_matrix, -r_refdef.vieworg[0], -r_refdef.vieworg[1], -r_refdef.vieworg[2]);
 	MatrixMultiply(vulkan_globals.view_matrix, translation_matrix);
 
+#if YSHEAR
+	TranslationMatrix(rotation_matrix, 0, 0, 0);
+	rotation_matrix[1 + 4 * 2] = tanf(DEG2RAD(-r_refdef.viewangles[0]));
+#else
+	RotationMatrix(rotation_matrix, DEG2RAD(r_refdef.viewangles[0]), 1.0f, 0.0f, 0.0f);
+#endif
+	MatrixMultiply(rotation_matrix, vulkan_globals.view_matrix);
+	memcpy(vulkan_globals.view_matrix, rotation_matrix, 16*sizeof(float));
+
 	// View projection matrix
 	memcpy(vulkan_globals.view_projection_matrix, vulkan_globals.projection_matrix, 16 * sizeof(float));
 	MatrixMultiply(vulkan_globals.view_projection_matrix, vulkan_globals.view_matrix);