Added support for transparent stroke colors (again).

Transparent strokes are rendered by means of transparent vertex colors.
To make this possible, Blender's internal renderer has been slightly
extended to allow transparent vertex colors.  When Material::vcol_alpha
is non-zero, the renderer takes MCol::a into account.

2 files changed, 30 insertions, 3 deletions

diff --git a/source/blender/freestyle/intern/blender_interface/BlenderStrokeRenderer.cpp b/source/blender/freestyle/intern/blender_interface/BlenderStrokeRenderer.cpp
index b3c77da0e23..30577287b72 100644
--- a/source/blender/freestyle/intern/blender_interface/BlenderStrokeRenderer.cpp
+++ b/source/blender/freestyle/intern/blender_interface/BlenderStrokeRenderer.cpp
@@ -62,6 +62,14 @@ BlenderStrokeRenderer::BlenderStrokeRenderer(Render* re)
 	Camera* camera = (Camera *) object_camera->data;
 	camera->type = CAM_ORTHO;
 	camera->ortho_scale = max(width,height);
+    camera->clipsta = 0.1f;
+    camera->clipend = 100.0f;
+
+    _z_delta = 0.00001f;
+    _z = camera->clipsta + _z_delta;
+
+    // test
+    //_z = 999.90f; _z_delta = 0.01f;
 	
 	object_camera->loc[0] = 0.5 * width;
 	object_camera->loc[1] = 0.5 * height;
@@ -74,7 +82,9 @@ BlenderStrokeRenderer::BlenderStrokeRenderer(Render* re)
 	// Material
 	material = add_material("stroke_material");
 	material->mode |= MA_VERTEXCOLP;
+	material->mode |= MA_TRANSP;
 	material->mode |= MA_SHLESS;
+	material->vcol_alpha = 1;
 }
 
 BlenderStrokeRenderer::~BlenderStrokeRenderer(){
@@ -125,6 +135,15 @@ void BlenderStrokeRenderer::store_object(Object *ob) const {
 	BLI_addhead(const_cast<ListBase *>(&objects), link);
 }
 
+float BlenderStrokeRenderer::get_stroke_vertex_z(void) const {
+    float z = _z;
+    BlenderStrokeRenderer *self = const_cast<BlenderStrokeRenderer *>(this);
+    if (!(_z < _z_delta * 100000.0f))
+        self->_z_delta *= 10.0f;
+    self->_z += _z_delta;
+    return -z;
+}
+
 void BlenderStrokeRenderer::RenderStrokeRep(StrokeRep *iStrokeRep) const{
   RenderStrokeRepBasic(iStrokeRep);
 }
@@ -252,13 +271,13 @@ void BlenderStrokeRenderer::RenderStrokeRepBasic(StrokeRep *iStrokeRep) const{
 					// first vertex
 					vertices->co[0] = svRep[0]->point2d()[0];
 					vertices->co[1] = svRep[0]->point2d()[1];
-					vertices->co[2] = 0.0;
+					vertices->co[2] = get_stroke_vertex_z();
 					++vertices;
 					
 					// second vertex
 					vertices->co[0] = svRep[1]->point2d()[0];
 					vertices->co[1] = svRep[1]->point2d()[1];
-					vertices->co[2] = 0.0;
+					vertices->co[2] = get_stroke_vertex_z();
 					++vertices;
 				}
 				visible = true;
@@ -266,7 +285,7 @@ void BlenderStrokeRenderer::RenderStrokeRepBasic(StrokeRep *iStrokeRep) const{
 				// vertex
 				vertices->co[0] = svRep[2]->point2d()[0];
 				vertices->co[1] = svRep[2]->point2d()[1];
-				vertices->co[2] = 0.0;
+				vertices->co[2] = get_stroke_vertex_z();
 				
 				// faces
 				faces->v1 = vertex_index - 2;
@@ -310,6 +329,11 @@ void BlenderStrokeRenderer::RenderStrokeRepBasic(StrokeRep *iStrokeRep) const{
 }
 
 Render* BlenderStrokeRenderer::RenderScene( Render *re ) {
+    Camera *camera = (Camera *)freestyle_scene->camera->data;
+    if (camera->clipend < _z)
+        camera->clipend = _z + _z_delta * 100.0f;
+    //cout << "clipsta " << camera->clipsta << ", clipend " << camera->clipend << endl;
+
 	freestyle_scene->r.mode &= ~( R_EDGE_FRS | R_SHADOW | R_SSS | R_PANORAMA | R_ENVMAP | R_MBLUR );
 	freestyle_scene->r.scemode &= ~( R_SINGLE_LAYER );
 	freestyle_scene->r.planes = R_PLANES32;
diff --git a/source/blender/freestyle/intern/blender_interface/BlenderStrokeRenderer.h b/source/blender/freestyle/intern/blender_interface/BlenderStrokeRenderer.h
index b8de204881a..5bee116457d 100644
--- a/source/blender/freestyle/intern/blender_interface/BlenderStrokeRenderer.h
+++ b/source/blender/freestyle/intern/blender_interface/BlenderStrokeRenderer.h
@@ -37,8 +37,11 @@ protected:
 	Scene* freestyle_scene;
 	Material* material;
 	ListBase objects;
+	float _z, _z_delta;
 
 	void store_object(Object *ob) const;
+
+	float get_stroke_vertex_z(void) const;
 };
 
 #endif // BLENDERSTROKERENDERER_H