43 lines
1.1 KiB
GLSL
43 lines
1.1 KiB
GLSL
uniform mat4 ProjectionMatrix;
|
|
|
|
/* simple depth reconstruction, see http://www.derschmale.com/2014/01/26/reconstructing-positions-from-the-depth-buffer
|
|
* we change the factors from the article to fit the OpennGL model. */
|
|
#ifdef PERSP_MATRIX
|
|
|
|
|
|
/* perspective camera code */
|
|
|
|
vec3 get_view_space_from_depth(in vec2 uvcoords, in vec3 viewvec_origin, in vec3 viewvec_diff, in float depth)
|
|
{
|
|
float d = 2.0 * depth - 1.0;
|
|
|
|
float zview = -ProjectionMatrix[3][2] / (d + ProjectionMatrix[2][2]);
|
|
|
|
return zview * (viewvec_origin + vec3(uvcoords, 0.0) * viewvec_diff);
|
|
}
|
|
|
|
vec4 get_view_space_z_from_depth(in vec4 near, in vec4 range, in vec4 depth)
|
|
{
|
|
vec4 d = 2.0 * depth - vec4(1.0);
|
|
|
|
/* return positive value, so sign differs! */
|
|
return vec4(ProjectionMatrix[3][2]) / (d + vec4(ProjectionMatrix[2][2]));
|
|
}
|
|
|
|
#else
|
|
/* orthographic camera code */
|
|
|
|
vec3 get_view_space_from_depth(in vec2 uvcoords, in vec3 viewvec_origin, in vec3 viewvec_diff, in float depth)
|
|
{
|
|
vec3 offset = vec3(uvcoords, depth);
|
|
|
|
return vec3(viewvec_origin + offset * viewvec_diff);
|
|
}
|
|
|
|
vec4 get_view_space_z_from_depth(in vec4 near, in vec4 range, in vec4 depth)
|
|
{
|
|
return -(near + depth * range);
|
|
}
|
|
|
|
#endif
|