diff options
Diffstat (limited to 'source/blender/gpu/shaders/gpu_shader_fx_lib.glsl')
-rw-r--r-- | source/blender/gpu/shaders/gpu_shader_fx_lib.glsl | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/source/blender/gpu/shaders/gpu_shader_fx_lib.glsl b/source/blender/gpu/shaders/gpu_shader_fx_lib.glsl new file mode 100644 index 00000000000..6c4bf3bb7a0 --- /dev/null +++ b/source/blender/gpu/shaders/gpu_shader_fx_lib.glsl @@ -0,0 +1,47 @@ +vec3 calculate_view_space_normal(in vec3 viewposition) +{ + vec3 normal = cross(normalize(dFdx(viewposition)), + normalize(dFdy(viewposition))); + normalize(normal); + return normal; +} + +/* 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 = -gl_ProjectionMatrix[3][2] / (d + gl_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(gl_ProjectionMatrix[3][2]) / (d + vec4(gl_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 |