void ohmd_calc_default_proj_matrices(ohmd_device_properties* props)
{
mat4x4f proj_base; // base projection matrix
// Calculate where the lens is on each screen,
// and with the given value offset the projection matrix.
float screen_center = props->hsize / 4.0f;
float lens_shift = screen_center - props->lens_sep / 2.0f;
float proj_offset = 4.0f * lens_shift / props->hsize;
// Setup the base projection matrix. Each eye mostly have the
// same projection matrix with the exception of the offset.
omat4x4f_init_perspective(&proj_base, props->fov, props->ratio, props->znear, props->zfar);
// Setup the two adjusted projection matricies. Each is setup to deal
// with the fact that the lens is not in the center of the screen.
// These matrices only change of the hardware changes, so static.
mat4x4f translate;
omat4x4f_init_translate(&translate, proj_offset, 0, 0);
omat4x4f_mult(&translate, &proj_base, &props->proj_left);
omat4x4f_init_translate(&translate, -proj_offset, 0, 0);
omat4x4f_mult(&translate, &proj_base, &props->proj_right);
}
static void calc_derived_values(rift_priv *priv)
{
priv->base.properties.hsize = priv->display_info.h_screen_size;
priv->base.properties.vsize = priv->display_info.v_screen_size;
priv->base.properties.hres = priv->display_info.h_resolution;
priv->base.properties.vres = priv->display_info.v_resolution;
priv->base.properties.lens_sep = priv->display_info.lens_separation;
priv->base.properties.lens_vpos = priv->display_info.v_center;
priv->base.properties.fov = DEG_TO_RAD(125.5144f); // TODO calculate.
// Calculate the screen ratio of each subscreen.
float full_ratio = (float)priv->display_info.h_resolution /
(float)priv->display_info.v_resolution;
float ratio = full_ratio / 2.0f;
priv->base.properties.ratio = ratio;
// Calculate where the lens is on each screen,
// and with the given value offset the projection matrix.
float screen_center = priv->display_info.h_screen_size / 4.0f;
float lens_shift = screen_center - priv->display_info.lens_separation / 2.0f;
float proj_offset = 4.0f * lens_shift / priv->display_info.h_screen_size;
priv->calc_values.proj_offset = proj_offset;
// Setup the base projection matrix. Each eye mostly have the
// same projection matrix with the exception of the offset.
omat4x4f_init_perspective(&priv->calc_values.proj_base,
priv->base.properties.fov,
priv->base.properties.ratio,
priv->base.properties.znear,
priv->base.properties.zfar);
// Setup the two adjusted projection matricies. Each is setup to deal
// with the fact that the lens is not in the center of the screen.
// These matrices only change of the hardware changes, so static.
mat4x4f translate;
omat4x4f_init_translate(&translate, proj_offset, 0, 0);
omat4x4f_mult(&translate,
&priv->calc_values.proj_base,
&priv->base.properties.proj_left);
omat4x4f_init_translate(&translate, -proj_offset, 0, 0);
omat4x4f_mult(&translate,
&priv->calc_values.proj_base,
&priv->base.properties.proj_right);
}
