From: Mikko Rasa <tdb@tdb.fi>
Date: Mon, 22 Dec 2014 23:56:45 +0000 (+0200)
Subject: Use vignetting to smoothly fade out the edges
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=b30892474ba39cd0b70bf924c65366a2f66443ab;p=libs%2Fvr.git

Use vignetting to smoothly fade out the edges

This somewhat reduces artifacts seen at the borders.
---

diff --git a/source/oculusriftcombiner.cpp b/source/oculusriftcombiner.cpp
index 492f5fd..a9808de 100644
--- a/source/oculusriftcombiner.cpp
+++ b/source/oculusriftcombiner.cpp
@@ -14,12 +14,14 @@ const char vs_source[] =
 	"varying vec2 texcoord_r;\n"
 	"varying vec2 texcoord_g;\n"
 	"varying vec2 texcoord_b;\n"
+	"varying float vignette;\n"
 	"void main()\n"
 	"{\n"
 	"	gl_Position = vec4(gl_Vertex.xy, 0.5, 1.0);\n"
 	"	texcoord_r = gl_MultiTexCoord0.xy;\n"
 	"	texcoord_g = gl_MultiTexCoord1.xy;\n"
 	"	texcoord_b = gl_MultiTexCoord2.xy;\n"
+	"	vignette = gl_MultiTexCoord3.x;\n"
 	"}\n";
 
 const char fs_source[] =
@@ -27,18 +29,19 @@ const char fs_source[] =
 	"varying vec2 texcoord_r;\n"
 	"varying vec2 texcoord_g;\n"
 	"varying vec2 texcoord_b;\n"
+	"varying float vignette;\n"
 	"void main()\n"
 	"{\n"
 	"	float r = texture2D(texture, texcoord_r).r;\n"
 	"	float g = texture2D(texture, texcoord_g).g;\n"
 	"	float b = texture2D(texture, texcoord_b).b;\n"
-	"	gl_FragColor = vec4(r, g, b, 1.0);\n"
+	"	gl_FragColor = vec4(vec3(r, g, b)*vignette, 1.0);\n"
 	"}\n";
 
 void create_distortion_mesh(Msp::GL::Mesh &mesh, ovrHmd hmd, ovrEyeType eye, const ovrFovPort &fov)
 {
 	ovrDistortionMesh ovr_mesh;
-	ovrHmd_CreateDistortionMesh(hmd, eye, fov, ovrDistortionCap_Chromatic, &ovr_mesh);
+	ovrHmd_CreateDistortionMesh(hmd, eye, fov, ovrDistortionCap_Chromatic|ovrDistortionCap_Vignette, &ovr_mesh);
 
 	ovrSizei tex_size = ovrHmd_GetFovTextureSize(hmd, eye, fov, 1.0);
 	ovrRecti view_rect;
@@ -57,6 +60,7 @@ void create_distortion_mesh(Msp::GL::Mesh &mesh, ovrHmd hmd, ovrEyeType eye, con
 		bld.multitexcoord(0, v.TanEyeAnglesR.x*scale.x+offset.x, 1.0f-(v.TanEyeAnglesR.y*scale.y+offset.y));
 		bld.multitexcoord(1, v.TanEyeAnglesG.x*scale.x+offset.x, 1.0f-(v.TanEyeAnglesG.y*scale.y+offset.y));
 		bld.multitexcoord(2, v.TanEyeAnglesB.x*scale.x+offset.x, 1.0f-(v.TanEyeAnglesB.y*scale.y+offset.y));
+		bld.multitexcoord(3, v.VignetteFactor);
 		bld.vertex(v.ScreenPosNDC.x, v.ScreenPosNDC.y);
 	}
 
@@ -74,8 +78,8 @@ namespace VR {
 
 OculusRiftCombiner::OculusRiftCombiner(const OculusRiftDevice &d):
 	device(d),
-	left_mesh((GL::VERTEX2, GL::TEXCOORD2,0, GL::TEXCOORD2,1, GL::TEXCOORD2,2)),
-	right_mesh((GL::VERTEX2, GL::TEXCOORD2,0, GL::TEXCOORD2,1, GL::TEXCOORD2,2)),
+	left_mesh((GL::VERTEX2, GL::TEXCOORD2,0, GL::TEXCOORD2,1, GL::TEXCOORD2,2, GL::TEXCOORD1,3)),
+	right_mesh((GL::VERTEX2, GL::TEXCOORD2,0, GL::TEXCOORD2,1, GL::TEXCOORD2,2, GL::TEXCOORD1,3)),
 	shprog(vs_source, fs_source)
 {
 	const OculusRiftDevice::Private &dev_priv = device.get_private();