private void SetShaderGlobals()
{
// For any shaders that want to use these numbers for distortion correction. But only
// if distortion correction is needed, yet not already being handled by another method.
if (GvrViewer.Instance.VRModeEnabled &&
GvrViewer.Instance.DistortionCorrection == GvrViewer.DistortionCorrectionMethod.None)
{
GvrProfile p = GvrViewer.Instance.Profile;
// Distortion vertex shader currently setup for only 6 coefficients.
if (p.viewer.inverse.Coef.Length > 6)
{
Debug.LogWarning("Inverse distortion correction has more than 6 coefficents. "
+ "Shader only supports 6.");
}
Matrix4x4 mat = new Matrix4x4()
{
};
for (int i = 0; i < p.viewer.inverse.Coef.Length; i++)
{
mat[i] = p.viewer.inverse.Coef[i];
}
Shader.SetGlobalMatrix("_Undistortion", mat);
float[] rect = new float[4];
p.GetLeftEyeVisibleTanAngles(rect);
float r = GvrProfile.GetMaxRadius(rect);
Shader.SetGlobalFloat("_MaxRadSq", r * r);
}
}
private static void ComputeMeshPoints(int width, int height, bool distortVertices,
out Vector3[] vertices, out Vector2[] tex)
{
float[] lensFrustum = new float[4];
float[] noLensFrustum = new float[4];
Rect viewport;
GvrProfile profile = GvrViewer.Instance.Profile;
profile.GetLeftEyeVisibleTanAngles(lensFrustum);
profile.GetLeftEyeNoLensTanAngles(noLensFrustum);
viewport = profile.GetLeftEyeVisibleScreenRect(noLensFrustum);
vertices = new Vector3[2 * width * height];
tex = new Vector2[2 * width * height];
for (int e = 0, vidx = 0; e < 2; e++)
{
for (int j = 0; j < height; j++)
{
for (int i = 0; i < width; i++, vidx++)
{
float u = (float)i / (width - 1);
float v = (float)j / (height - 1);
float s, t; // The texture coordinates in StereoScreen to read from.
if (distortVertices)
{
// Grid points regularly spaced in StreoScreen, and barrel distorted in the mesh.
s = u;
t = v;
float x = Mathf.Lerp(lensFrustum[0], lensFrustum[2], u);
float y = Mathf.Lerp(lensFrustum[3], lensFrustum[1], v);
float d = Mathf.Sqrt(x * x + y * y);
float r = profile.viewer.distortion.distortInv(d);
float p = x * r / d;
float q = y * r / d;
u = (p - noLensFrustum[0]) / (noLensFrustum[2] - noLensFrustum[0]);
v = (q - noLensFrustum[3]) / (noLensFrustum[1] - noLensFrustum[3]);
}
else
{
// Grid points regularly spaced in the mesh, and pincushion distorted in
// StereoScreen.
float p = Mathf.Lerp(noLensFrustum[0], noLensFrustum[2], u);
float q = Mathf.Lerp(noLensFrustum[3], noLensFrustum[1], v);
float r = Mathf.Sqrt(p * p + q * q);
float d = profile.viewer.distortion.distort(r);
float x = p * d / r;
float y = q * d / r;
s = Mathf.Clamp01((x - lensFrustum[0]) / (lensFrustum[2] - lensFrustum[0]));
t = Mathf.Clamp01((y - lensFrustum[3]) / (lensFrustum[1] - lensFrustum[3]));
}
// Convert u,v to mesh screen coordinates.
float aspect = profile.screen.width / profile.screen.height;
u = (viewport.x + u * viewport.width - 0.5f) * aspect;
v = viewport.y + v * viewport.height - 0.5f;
vertices[vidx] = new Vector3(u, v, 1);
// Adjust s to account for left/right split in StereoScreen.
s = (s + e) / 2;
tex[vidx] = new Vector2(s, t);
}
}
float w = lensFrustum[2] - lensFrustum[0];
lensFrustum[0] = -(w + lensFrustum[0]);
lensFrustum[2] = w - lensFrustum[2];
w = noLensFrustum[2] - noLensFrustum[0];
noLensFrustum[0] = -(w + noLensFrustum[0]);
noLensFrustum[2] = w - noLensFrustum[2];
viewport.x = 1 - (viewport.x + viewport.width);
}
}