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Diffstat (limited to 'source/blender/compositor/realtime_compositor/COM_compile_state.hh')
| -rw-r--r-- | source/blender/compositor/realtime_compositor/COM_compile_state.hh | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/source/blender/compositor/realtime_compositor/COM_compile_state.hh b/source/blender/compositor/realtime_compositor/COM_compile_state.hh new file mode 100644 index 00000000000..924919bbef6 --- /dev/null +++ b/source/blender/compositor/realtime_compositor/COM_compile_state.hh @@ -0,0 +1,170 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#pragma once + +#include "BLI_map.hh" + +#include "NOD_derived_node_tree.hh" + +#include "COM_domain.hh" +#include "COM_node_operation.hh" +#include "COM_scheduler.hh" +#include "COM_shader_operation.hh" + +namespace blender::realtime_compositor { + +using namespace nodes::derived_node_tree_types; + +/* ------------------------------------------------------------------------------------------------ + * Compile State + * + * The compile state is a utility class used to track the state of compilation when compiling the + * node tree. In particular, it tracks two important pieces of information, each of which is + * described in one of the following sections. + * + * First, it stores a mapping between all nodes and the operations they were compiled into. The + * mapping are stored independently depending on the type of the operation in the node_operations_ + * and shader_operations_ maps. So those two maps are mutually exclusive. The compiler should call + * the map_node_to_node_operation and map_node_to_shader_operation methods to populate those maps + * as soon as it compiles a node or multiple nodes into an operation. Those maps are used to + * retrieve the results of outputs linked to the inputs of operations. For more details, see the + * get_result_from_output_socket method. For the node tree shown below, nodes 1, 2, and 6 are + * mapped to their compiled operations in the node_operation_ map. While nodes 3 and 4 are both + * mapped to the first shader operation, and node 5 is mapped to the second shader operation in the + * shader_operations_ map. + * + * Shader Operation 1 Shader Operation 2 + * +-----------------------------------+ +------------------+ + * .------------. | .------------. .------------. | | .------------. | .------------. + * | Node 1 | | | Node 3 | | Node 4 | | | | Node 5 | | | Node 6 | + * | |----|--| |--| |---|-----|--| |--|--| | + * | | .-|--| | | | | .--|--| | | | | + * '------------' | | '------------' '------------' | | | '------------' | '------------' + * | +-----------------------------------+ | +------------------+ + * .------------. | | + * | Node 2 | | | + * | |--'----------------------------------------' + * | | + * '------------' + * + * Second, it stores the shader compile unit as well as its domain. One should first go over the + * discussion in COM_evaluator.hh for a high level description of the mechanism of the compile + * unit. The one important detail in this class is the should_compile_shader_compile_unit method, + * which implements the criteria of whether the compile unit should be compiled given the node + * currently being processed as an argument. Those criteria are described as follows. If the + * compile unit is empty as is the case when processing nodes 1, 2, and 3, then it plainly + * shouldn't be compiled. If the given node is not a shader node, then it can't be added to the + * compile unit and the unit is considered complete and should be compiled, as is the case when + * processing node 6. If the computed domain of the given node is not compatible with the domain of + * the compiled unit, then it can't be added to the unit and the unit is considered complete and + * should be compiled, as is the case when processing node 5, more on this in the next section. + * Otherwise, the given node is compatible with the compile unit and can be added to it, so the + * unit shouldn't be compiled just yet, as is the case when processing node 4. + * + * Special attention should be given to the aforementioned domain compatibility criterion. One + * should first go over the discussion in COM_domain.hh for more information on domains. When a + * compile unit gets eventually compiled to a shader operation, that operation will have a certain + * operation domain, and any node that gets added to the compile unit should itself have a computed + * node domain that is compatible with that operation domain, otherwise, had the node been compiled + * into its own operation separately, the result would have been be different. For instance, + * consider the above node tree where node 1 outputs a 100x100 result, node 2 outputs a 50x50 + * result, the first input in node 3 has the highest domain priority, and the second input in node + * 5 has the highest domain priority. In this case, shader operation 1 will output a 100x100 + * result, and shader operation 2 will output a 50x50 result, because that's the computed operation + * domain for each of them. So node 6 will get a 50x50 result. Now consider the same node tree, but + * where all three nodes 3, 4, and 5 were compiled into a single shader operation as shown the node + * tree below. In that case, shader operation 1 will output a 100x100 result, because that's its + * computed operation domain. So node 6 will get a 100x100 result. As can be seen, the final result + * is different even though the node tree is the same. That's why the compiler can decide to + * compile the compile unit early even though further nodes can still be technically added to it. + * + * Shader Operation 1 + * +------------------------------------------------------+ + * .------------. | .------------. .------------. .------------. | .------------. + * | Node 1 | | | Node 3 | | Node 4 | | Node 5 | | | Node 6 | + * | |----|--| |--| |------| |--|--| | + * | | .-|--| | | | .---| | | | | + * '------------' | | '------------' '------------' | '------------' | '------------' + * | +----------------------------------|-------------------+ + * .------------. | | + * | Node 2 | | | + * | |--'------------------------------------' + * | | + * '------------' + * + * To check for the domain compatibility between the compile unit and the node being processed, + * the domain of the compile unit is assumed to be the domain of the first node whose computed + * domain is not an identity domain. Identity domains corresponds to single value results, so those + * are always compatible with any domain. The domain of the compile unit is computed and set in + * the add_node_to_shader_compile_unit method. When processing a node, the computed domain of node + * is compared to the compile unit domain in the should_compile_shader_compile_unit method, noting + * that identity domains are always compatible. Node domains are computed in the + * compute_shader_node_domain method, which is analogous to Operation::compute_domain for nodes + * that are not yet compiled. */ +class CompileState { + private: + /* A reference to the node execution schedule that is being compiled. */ + const Schedule &schedule_; + /* Those two maps associate each node with the operation it was compiled into. Each node is + * either compiled into a node operation and added to node_operations, or compiled into a shader + * operation and added to shader_operations. Those maps are used to retrieve the results of + * outputs linked to the inputs of operations. See the get_result_from_output_socket method for + * more information. */ + Map<DNode, NodeOperation *> node_operations_; + Map<DNode, ShaderOperation *> shader_operations_; + /* A contiguous subset of the node execution schedule that contains the group of nodes that will + * be compiled together into a Shader Operation. See the discussion in COM_evaluator.hh for + * more information. */ + ShaderCompileUnit shader_compile_unit_; + /* The domain of the shader compile unit. */ + Domain shader_compile_unit_domain_ = Domain::identity(); + + public: + /* Construct a compile state from the node execution schedule being compiled. */ + CompileState(const Schedule &schedule); + + /* Get a reference to the node execution schedule being compiled. */ + const Schedule &get_schedule(); + + /* Add an association between the given node and the give node operation that the node was + * compiled into in the node_operations_ map. */ + void map_node_to_node_operation(DNode node, NodeOperation *operation); + + /* Add an association between the given node and the give shader operation that the node was + * compiled into in the shader_operations_ map. */ + void map_node_to_shader_operation(DNode node, ShaderOperation *operation); + + /* Returns a reference to the result of the operation corresponding to the given output that the + * given output's node was compiled to. */ + Result &get_result_from_output_socket(DOutputSocket output); + + /* Add the given node to the compile unit. And if the domain of the compile unit is not yet + * determined or was determined to be an identity domain, update it to the computed domain for + * the give node. */ + void add_node_to_shader_compile_unit(DNode node); + + /* Get a reference to the shader compile unit. */ + ShaderCompileUnit &get_shader_compile_unit(); + + /* Clear the compile unit. This should be called once the compile unit is compiled to ready it to + * track the next potential compile unit. */ + void reset_shader_compile_unit(); + + /* Determines if the compile unit should be compiled based on a number of criteria give the node + * currently being processed. Those criteria are as follows: + * - If compile unit is empty, then it can't and shouldn't be compiled. + * - If the given node is not a shader node, then it can't be added to the compile unit + * and the unit is considered complete and should be compiled. + * - If the computed domain of the given node is not compatible with the domain of the compile + * unit, then it can't be added to it and the unit is considered complete and should be + * compiled. */ + bool should_compile_shader_compile_unit(DNode node); + + private: + /* Compute the node domain of the given shader node. This is analogous to the + * Operation::compute_domain method, except it is computed from the node itself as opposed to a + * compiled operation. See the discussion in COM_domain.hh for more information. */ + Domain compute_shader_node_domain(DNode node); +}; + +} // namespace blender::realtime_compositor |