Compositing works with X-Ray.

Basically, before drawing X-Rays, we now bind a second depth buffer.
After drawing XRays, we do an extra resolve pass where we overwrite the
non-XRay depth buffer in pixels where the depth is not maximum (which
means background pixel, since depth is cleared before drawing X-Ray
objects).

This ensures both scene and X-Rays keep their depth values and are ready
for compositing. Well, the odd effect due to depth discontinuities can be
expected, and X-Rays are a bit more expensive (extra buffer + resolve pass)
but at least X-Rays won't invalidate depth values anymore. Whee!

1 files changed, 14 insertions, 0 deletions

diff --git a/source/blender/gpu/shaders/gpu_shader_fx_depth_resolve.glsl b/source/blender/gpu/shaders/gpu_shader_fx_depth_resolve.glsl
new file mode 100644
index 00000000000..e04cd7d3306
--- /dev/null
+++ b/source/blender/gpu/shaders/gpu_shader_fx_depth_resolve.glsl
@@ -0,0 +1,14 @@
+uniform sampler2D depthbuffer;
+varying vec4 uvcoordsvar;
+
+void main(void)
+{
+	float depth = texture2D(depthbuffer, uvcoordsvar.xy).r;
+
+	/* XRay background, discard */
+	if (depth >= 1.0) {
+		discard;
+	}
+
+	gl_FragDepth = depth;
+}