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Simplify ShiftedEyePose::GetProjection() maths.

This commit is contained in:
Christopher Bruns 2015-10-31 08:02:41 -04:00
parent 789dca2ab3
commit 382d2cf74f
1 changed files with 2 additions and 6 deletions
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8
src/gl/stereo3d/gl_stereo_leftright.cpp
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@ -13,20 +13,16 @@ namespace s3d {
/* virtual */ /* virtual */
VSMatrix ShiftedEyePose::GetProjection(FLOATTYPE fov, FLOATTYPE aspectRatio, FLOATTYPE fovRatio) const VSMatrix ShiftedEyePose::GetProjection(FLOATTYPE fov, FLOATTYPE aspectRatio, FLOATTYPE fovRatio) const
{ {
// Lifted from gl_scene.cpp FGLRenderer::SetProjection()
FLOATTYPE fovy = 2 * RAD2DEG(atan(tan(DEG2RAD(fov) / 2) / fovRatio));
double zNear = 5.0; double zNear = 5.0;
double zFar = 65536.0; double zFar = 65536.0;
// For stereo 3D, use asymmetric frustum shift in projection matrix // For stereo 3D, use asymmetric frustum shift in projection matrix
// Q: shouldn't shift vary with roll angle, at least for desktop display? // Q: shouldn't shift vary with roll angle, at least for desktop display?
// A: No. (lab) roll is not measured on desktop display (yet) // A: No. (lab) roll is not measured on desktop display (yet)
double frustumShift = zNear * shift / vr_screendist; // meters cancel double frustumShift = zNear * shift / vr_screendist; // meters cancel, leaving doom units
// double frustumShift = 0; // Turning off shift for debugging // double frustumShift = 0; // Turning off shift for debugging
double fH = tan(DEG2RAD(fovy/2)) * zNear; double fH = zNear * tan(DEG2RAD(fov) / 2) / fovRatio;
double fW = fH * aspectRatio; double fW = fH * aspectRatio;
// Emulate glFrustum command:
// glFrustum(-fW - frustumShift, fW - frustumShift, -fH, fH, zNear, zFar);
double left = -fW - frustumShift; double left = -fW - frustumShift;
double right = fW - frustumShift; double right = fW - frustumShift;
double bottom = -fH; double bottom = -fH;