Blender Internal: Add "Lamp Data" shader node that allows shaders to acquire information such as light vector from specified Lamp.

For now this provides the following outputs:

- Color
- Light Vector
- Distance
- Shadow
- Visibility Factor

Note: Color output is multiplied by the lamp energy.  Multiplication of
color*max(dot(light_vector,normal_vector),0)*shadow*visibility_factor
produces the exact same result as the Lambert shader.

Many thanks to Brecht for code review and discussion!

1 files changed, 47 insertions, 0 deletions

diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index ed7a2f4ede0..8e7194bb4a1 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -355,6 +355,11 @@ int GPU_material_bound(GPUMaterial *material)
 	return material->bound;
 }
 
+Scene *GPU_material_scene(GPUMaterial *material)
+{
+	return material->scene;
+}
+
 void GPU_material_vertex_attributes(GPUMaterial *material, GPUVertexAttribs *attribs)
 {
 	*attribs = material->attribs;
@@ -1953,6 +1958,48 @@ int GPU_lamp_shadow_layer(GPULamp *lamp)
 		return -1;
 }
 
+GPUNodeLink *GPU_lamp_get_data(GPUMaterial *mat, GPULamp *lamp, GPUNodeLink **col, GPUNodeLink **lv, GPUNodeLink **dist, GPUNodeLink **shadow)
+{
+	GPUNodeLink *visifac;
+
+	*col = GPU_dynamic_uniform(lamp->dyncol, GPU_DYNAMIC_LAMP_DYNCOL, lamp->ob);
+	visifac = lamp_get_visibility(mat, lamp, lv, dist);
+	shade_light_textures(mat, lamp, col);
+
+	if (GPU_lamp_has_shadow_buffer(lamp)) {
+		GPUNodeLink *vn, *inp;
+
+		GPU_link(mat, "shade_norm", GPU_builtin(GPU_VIEW_NORMAL), &vn);
+		GPU_link(mat, "shade_inp", vn, *lv, &inp);
+		mat->dynproperty |= DYN_LAMP_PERSMAT;
+
+		if (lamp->la->shadowmap_type == LA_SHADMAP_VARIANCE) {
+			GPU_link(mat, "shadows_only_vsm",
+				 GPU_builtin(GPU_VIEW_POSITION),
+				 GPU_dynamic_texture(lamp->tex, GPU_DYNAMIC_SAMPLER_2DSHADOW, lamp->ob),
+				 GPU_dynamic_uniform((float*)lamp->dynpersmat, GPU_DYNAMIC_LAMP_DYNPERSMAT, lamp->ob),
+				 GPU_uniform(&lamp->bias), GPU_uniform(&lamp->la->bleedbias),
+				 GPU_uniform(lamp->shadow_color), inp, shadow);
+		}
+		else {
+			GPU_link(mat, "shadows_only",
+				 GPU_builtin(GPU_VIEW_POSITION),
+				 GPU_dynamic_texture(lamp->tex, GPU_DYNAMIC_SAMPLER_2DSHADOW, lamp->ob),
+				 GPU_dynamic_uniform((float*)lamp->dynpersmat, GPU_DYNAMIC_LAMP_DYNPERSMAT, lamp->ob),
+				 GPU_uniform(&lamp->bias), GPU_uniform(lamp->shadow_color), inp, shadow);
+		}
+	}
+	else {
+		GPU_link(mat, "set_rgb_one", shadow);
+	}
+
+	/* ensure shadow buffer and lamp textures will be updated */
+	add_user_list(&mat->lamps, lamp);
+	add_user_list(&lamp->materials, mat->ma);
+
+	return visifac;
+}
+
 /* export the GLSL shader */
 
 GPUShaderExport *GPU_shader_export(struct Scene *scene, struct Material *ma)