blender/intern/cycles/render/graph.cpp
2012-06-09 17:22:52 +00:00

538 lines
14 KiB
C++

/*
* Copyright 2011, Blender Foundation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include "attribute.h"
#include "graph.h"
#include "nodes.h"
#include "util_algorithm.h"
#include "util_debug.h"
#include "util_foreach.h"
CCL_NAMESPACE_BEGIN
/* Input and Output */
ShaderInput::ShaderInput(ShaderNode *parent_, const char *name_, ShaderSocketType type_)
{
parent = parent_;
name = name_;
type = type_;
link = NULL;
value = make_float3(0, 0, 0);
stack_offset = SVM_STACK_INVALID;
default_value = NONE;
osl_only = false;
}
ShaderOutput::ShaderOutput(ShaderNode *parent_, const char *name_, ShaderSocketType type_)
{
parent = parent_;
name = name_;
type = type_;
stack_offset = SVM_STACK_INVALID;
}
/* Node */
ShaderNode::ShaderNode(const char *name_)
{
name = name_;
id = -1;
bump = SHADER_BUMP_NONE;
}
ShaderNode::~ShaderNode()
{
foreach(ShaderInput *socket, inputs)
delete socket;
foreach(ShaderOutput *socket, outputs)
delete socket;
}
ShaderInput *ShaderNode::input(const char *name)
{
foreach(ShaderInput *socket, inputs)
if(strcmp(socket->name, name) == 0)
return socket;
return NULL;
}
ShaderOutput *ShaderNode::output(const char *name)
{
foreach(ShaderOutput *socket, outputs)
if(strcmp(socket->name, name) == 0)
return socket;
return NULL;
}
ShaderInput *ShaderNode::add_input(const char *name, ShaderSocketType type, float value)
{
ShaderInput *input = new ShaderInput(this, name, type);
input->value.x = value;
inputs.push_back(input);
return input;
}
ShaderInput *ShaderNode::add_input(const char *name, ShaderSocketType type, float3 value)
{
ShaderInput *input = new ShaderInput(this, name, type);
input->value = value;
inputs.push_back(input);
return input;
}
ShaderInput *ShaderNode::add_input(const char *name, ShaderSocketType type, ShaderInput::DefaultValue value, bool osl_only)
{
ShaderInput *input = add_input(name, type);
input->default_value = value;
input->osl_only = osl_only;
return input;
}
ShaderOutput *ShaderNode::add_output(const char *name, ShaderSocketType type)
{
ShaderOutput *output = new ShaderOutput(this, name, type);
outputs.push_back(output);
return output;
}
void ShaderNode::attributes(AttributeRequestSet *attributes)
{
foreach(ShaderInput *input, inputs) {
if(!input->link) {
if(input->default_value == ShaderInput::TEXTURE_GENERATED)
attributes->add(ATTR_STD_GENERATED);
else if(input->default_value == ShaderInput::TEXTURE_UV)
attributes->add(ATTR_STD_UV);
}
}
}
/* Graph */
ShaderGraph::ShaderGraph()
{
finalized = false;
add(new OutputNode());
}
ShaderGraph::~ShaderGraph()
{
foreach(ShaderNode *node, nodes)
delete node;
}
ShaderNode *ShaderGraph::add(ShaderNode *node)
{
assert(!finalized);
node->id = nodes.size();
nodes.push_back(node);
return node;
}
ShaderNode *ShaderGraph::output()
{
return nodes.front();
}
ShaderGraph *ShaderGraph::copy()
{
ShaderGraph *newgraph = new ShaderGraph();
/* copy nodes */
set<ShaderNode*> nodes_all;
foreach(ShaderNode *node, nodes)
nodes_all.insert(node);
map<ShaderNode*, ShaderNode*> nodes_copy;
copy_nodes(nodes_all, nodes_copy);
/* add nodes (in same order, so output is still first) */
newgraph->nodes.clear();
foreach(ShaderNode *node, nodes)
newgraph->add(nodes_copy[node]);
return newgraph;
}
void ShaderGraph::connect(ShaderOutput *from, ShaderInput *to)
{
assert(!finalized);
assert(from && to);
if(to->link) {
fprintf(stderr, "ShaderGraph connect: input already connected.\n");
return;
}
if(from->type != to->type) {
/* for closures we can't do automatic conversion */
if(from->type == SHADER_SOCKET_CLOSURE || to->type == SHADER_SOCKET_CLOSURE) {
fprintf(stderr, "ShaderGraph connect: can only connect closure to closure.\n");
return;
}
/* add automatic conversion node in case of type mismatch */
ShaderNode *convert = add(new ConvertNode(from->type, to->type));
connect(from, convert->inputs[0]);
connect(convert->outputs[0], to);
}
else {
/* types match, just connect */
to->link = from;
from->links.push_back(to);
}
}
void ShaderGraph::disconnect(ShaderInput *to)
{
assert(!finalized);
assert(to->link);
ShaderOutput *from = to->link;
to->link = NULL;
from->links.erase(remove(from->links.begin(), from->links.end(), to), from->links.end());
}
void ShaderGraph::finalize(bool do_bump, bool do_osl)
{
/* before compiling, the shader graph may undergo a number of modifications.
* currently we set default geometry shader inputs, and create automatic bump
* from displacement. a graph can be finalized only once, and should not be
* modified afterwards. */
if(!finalized) {
clean();
default_inputs(do_osl);
if(do_bump)
bump_from_displacement();
finalized = true;
}
}
void ShaderGraph::find_dependencies(set<ShaderNode*>& dependencies, ShaderInput *input)
{
/* find all nodes that this input dependes on directly and indirectly */
ShaderNode *node = (input->link)? input->link->parent: NULL;
if(node) {
foreach(ShaderInput *in, node->inputs)
find_dependencies(dependencies, in);
dependencies.insert(node);
}
}
void ShaderGraph::copy_nodes(set<ShaderNode*>& nodes, map<ShaderNode*, ShaderNode*>& nnodemap)
{
/* copy a set of nodes, and the links between them. the assumption is
* made that all nodes that inputs are linked to are in the set too. */
/* copy nodes */
foreach(ShaderNode *node, nodes) {
ShaderNode *nnode = node->clone();
nnodemap[node] = nnode;
nnode->inputs.clear();
nnode->outputs.clear();
foreach(ShaderInput *input, node->inputs) {
ShaderInput *ninput = new ShaderInput(*input);
nnode->inputs.push_back(ninput);
ninput->parent = nnode;
ninput->link = NULL;
}
foreach(ShaderOutput *output, node->outputs) {
ShaderOutput *noutput = new ShaderOutput(*output);
nnode->outputs.push_back(noutput);
noutput->parent = nnode;
noutput->links.clear();
}
}
/* recreate links */
foreach(ShaderNode *node, nodes) {
foreach(ShaderInput *input, node->inputs) {
if(input->link) {
/* find new input and output */
ShaderNode *nfrom = nnodemap[input->link->parent];
ShaderNode *nto = nnodemap[input->parent];
ShaderOutput *noutput = nfrom->output(input->link->name);
ShaderInput *ninput = nto->input(input->name);
/* connect */
connect(noutput, ninput);
}
}
}
}
void ShaderGraph::remove_proxy_nodes(vector<bool>& removed)
{
foreach(ShaderNode *node, nodes) {
ProxyNode *proxy = dynamic_cast<ProxyNode*>(node);
if (proxy) {
ShaderInput *input = proxy->inputs[0];
ShaderOutput *output = proxy->outputs[0];
/* temp. copy of the output links list.
* output->links is modified when we disconnect!
*/
vector<ShaderInput*> links(output->links);
ShaderOutput *from = input->link;
/* bypass the proxy node */
if (from) {
disconnect(input);
foreach(ShaderInput *to, links) {
disconnect(to);
connect(from, to);
}
}
else {
foreach(ShaderInput *to, links) {
disconnect(to);
/* transfer the default input value to the target socket */
to->set(input->value);
}
}
removed[proxy->id] = true;
}
/* remove useless mix closures nodes */
MixClosureNode *mix = dynamic_cast<MixClosureNode*>(node);
if(mix) {
if(mix->outputs[0]->links.size() && mix->inputs[1]->link == mix->inputs[2]->link) {
ShaderOutput *output = mix->inputs[1]->link;
vector<ShaderInput*> inputs = mix->outputs[0]->links;
foreach(ShaderInput *sock, mix->inputs)
if(sock->link)
disconnect(sock);
foreach(ShaderInput *input, inputs) {
disconnect(input);
if (output)
connect(output, input);
}
}
}
}
}
void ShaderGraph::break_cycles(ShaderNode *node, vector<bool>& visited, vector<bool>& on_stack)
{
visited[node->id] = true;
on_stack[node->id] = true;
foreach(ShaderInput *input, node->inputs) {
if(input->link) {
ShaderNode *depnode = input->link->parent;
if(on_stack[depnode->id]) {
/* break cycle */
disconnect(input);
fprintf(stderr, "ShaderGraph: detected cycle in graph, connection removed.\n");
}
else if(!visited[depnode->id]) {
/* visit dependencies */
break_cycles(depnode, visited, on_stack);
}
}
}
on_stack[node->id] = false;
}
void ShaderGraph::clean()
{
/* we do two things here: find cycles and break them, and remove unused
* nodes that don't feed into the output. how cycles are broken is
* undefined, they are invalid input, the important thing is to not crash */
vector<bool> removed(nodes.size(), false);
vector<bool> visited(nodes.size(), false);
vector<bool> on_stack(nodes.size(), false);
list<ShaderNode*> newnodes;
/* remove proxy nodes */
remove_proxy_nodes(removed);
foreach(ShaderNode *node, nodes) {
if(!removed[node->id])
newnodes.push_back(node);
else
delete node;
}
nodes = newnodes;
newnodes.clear();
/* break cycles */
break_cycles(output(), visited, on_stack);
/* remove unused nodes */
foreach(ShaderNode *node, nodes) {
if(visited[node->id])
newnodes.push_back(node);
else
delete node;
}
nodes = newnodes;
}
void ShaderGraph::default_inputs(bool do_osl)
{
/* nodes can specify default texture coordinates, for now we give
* everything the position by default, except for the sky texture */
ShaderNode *geom = NULL;
ShaderNode *texco = NULL;
foreach(ShaderNode *node, nodes) {
foreach(ShaderInput *input, node->inputs) {
if(!input->link && !(input->osl_only && !do_osl)) {
if(input->default_value == ShaderInput::TEXTURE_GENERATED) {
if(!texco)
texco = new TextureCoordinateNode();
connect(texco->output("Generated"), input);
}
else if(input->default_value == ShaderInput::TEXTURE_UV) {
if(!texco)
texco = new TextureCoordinateNode();
connect(texco->output("UV"), input);
}
else if(input->default_value == ShaderInput::INCOMING) {
if(!geom)
geom = new GeometryNode();
connect(geom->output("Incoming"), input);
}
else if(input->default_value == ShaderInput::NORMAL) {
if(!geom)
geom = new GeometryNode();
connect(geom->output("Normal"), input);
}
else if(input->default_value == ShaderInput::POSITION) {
if(!geom)
geom = new GeometryNode();
connect(geom->output("Position"), input);
}
}
}
}
if(geom)
add(geom);
if(texco)
add(texco);
}
void ShaderGraph::bump_from_displacement()
{
/* generate bump mapping automatically from displacement. bump mapping is
* done using a 3-tap filter, computing the displacement at the center,
* and two other positions shifted by ray differentials.
*
* since the input to displacement is a node graph, we need to ensure that
* all texture coordinates use are shift by the ray differentials. for this
* reason we make 3 copies of the node subgraph defining the displacement,
* with each different geometry and texture coordinate nodes that generate
* different shifted coordinates.
*
* these 3 displacement values are then fed into the bump node, which will
* modify the normal. */
ShaderInput *displacement_in = output()->input("Displacement");
if(!displacement_in->link)
return;
/* find dependencies for the given input */
set<ShaderNode*> nodes_displace;
find_dependencies(nodes_displace, displacement_in);
/* copy nodes for 3 bump samples */
map<ShaderNode*, ShaderNode*> nodes_center;
map<ShaderNode*, ShaderNode*> nodes_dx;
map<ShaderNode*, ShaderNode*> nodes_dy;
copy_nodes(nodes_displace, nodes_center);
copy_nodes(nodes_displace, nodes_dx);
copy_nodes(nodes_displace, nodes_dy);
/* mark nodes to indicate they are use for bump computation, so
* that any texture coordinates are shifted by dx/dy when sampling */
foreach(NodePair& pair, nodes_center)
pair.second->bump = SHADER_BUMP_CENTER;
foreach(NodePair& pair, nodes_dx)
pair.second->bump = SHADER_BUMP_DX;
foreach(NodePair& pair, nodes_dy)
pair.second->bump = SHADER_BUMP_DY;
/* add bump node and connect copied graphs to it */
ShaderNode *bump = add(new BumpNode());
ShaderOutput *out = displacement_in->link;
ShaderOutput *out_center = nodes_center[out->parent]->output(out->name);
ShaderOutput *out_dx = nodes_dx[out->parent]->output(out->name);
ShaderOutput *out_dy = nodes_dy[out->parent]->output(out->name);
connect(out_center, bump->input("SampleCenter"));
connect(out_dx, bump->input("SampleX"));
connect(out_dy, bump->input("SampleY"));
/* connect bump output to normal input nodes that aren't set yet. actually
* this will only set the normal input to the geometry node that we created
* and connected to all other normal inputs already. */
foreach(ShaderNode *node, nodes)
foreach(ShaderInput *input, node->inputs)
if(!input->link && input->default_value == ShaderInput::NORMAL)
connect(bump->output("Normal"), input);
/* finally, add the copied nodes to the graph. we can't do this earlier
* because we would create dependency cycles in the above loop */
foreach(NodePair& pair, nodes_center)
add(pair.second);
foreach(NodePair& pair, nodes_dx)
add(pair.second);
foreach(NodePair& pair, nodes_dy)
add(pair.second);
}
CCL_NAMESPACE_END