Realtime Compositor: Add needed GPU module changes

This patch implements the necessary changes to the GPU module that are
needed by the realtime compositor.

A new function GPU_material_from_callbacks was added to construct a GPU
material from a number of callbacks. A callback to construct the
material graph by adding and linking the necessary GPU material nodes.
And the existing code generator callback. This essentially allows the
construction of GPU materials independent of node trees and without the
need to do any node tree localization.

A new composite source output to the code generator was added. This
output contains the serialization of nodes that are tagged with
GPU_NODE_TAG_COMPOSITOR, which are the nodes linked to the newly added
composite output links.

Two new GPU uniform setters were added for int2 and matrix3 types.

Shader create info now supports generated compute sources.

Shaders starting with gpu_shader_compositor are now considered part of
the shader library.

Additionally, two fixes were implemented. First, GPU setter node
de-duplication now appropriately increments the reference count of the
references resources. Second, unlinked sockets now get their value from
their associated GPU node stack instead of the socket itself.

Differential Revision: https://developer.blender.org/D14690

Reviewed By: Clement

1 files changed, 49 insertions, 3 deletions

diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index 4d3ea3e0c99..a4842ef0e43 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -141,7 +141,7 @@ static void gpu_material_ramp_texture_build(GPUMaterial *mat)
   mat->coba_builder = NULL;
 }
 
-static void gpu_material_free_single(GPUMaterial *material)
+void GPU_material_free_single(GPUMaterial *material)
 {
   bool do_free = atomic_sub_and_fetch_uint32(&material->refcount, 1) == 0;
   if (!do_free) {
@@ -173,7 +173,7 @@ void GPU_material_free(ListBase *gpumaterial)
   LISTBASE_FOREACH (LinkData *, link, gpumaterial) {
     GPUMaterial *material = link->data;
     DRW_deferred_shader_remove(material);
-    gpu_material_free_single(material);
+    GPU_material_free_single(material);
   }
   BLI_freelistN(gpumaterial);
 }
@@ -538,6 +538,13 @@ void GPU_material_add_output_link_aov(GPUMaterial *material, GPUNodeLink *link,
   BLI_addtail(&material->graph.outlink_aovs, aov_link);
 }
 
+void GPU_material_add_output_link_composite(GPUMaterial *material, GPUNodeLink *link)
+{
+  GPUNodeGraphOutputLink *compositor_link = MEM_callocN(sizeof(GPUNodeGraphOutputLink), __func__);
+  compositor_link->outlink = link;
+  BLI_addtail(&material->graph.outlink_compositor, compositor_link);
+}
+
 char *GPU_material_split_sub_function(GPUMaterial *material,
                                       eGPUType return_type,
                                       GPUNodeLink **link)
@@ -721,7 +728,7 @@ void GPU_material_acquire(GPUMaterial *mat)
 
 void GPU_material_release(GPUMaterial *mat)
 {
-  gpu_material_free_single(mat);
+  GPU_material_free_single(mat);
 }
 
 void GPU_material_compile(GPUMaterial *mat)
@@ -772,3 +779,42 @@ void GPU_materials_free(Main *bmain)
   // BKE_world_defaults_free_gpu();
   BKE_material_defaults_free_gpu();
 }
+
+GPUMaterial *GPU_material_from_callbacks(ConstructGPUMaterialFn construct_function_cb,
+                                         GPUCodegenCallbackFn generate_code_function_cb,
+                                         void *thunk)
+{
+  /* Allocate a new material and its material graph, and initialize its reference count. */
+  GPUMaterial *material = MEM_callocN(sizeof(GPUMaterial), "GPUMaterial");
+  material->graph.used_libraries = BLI_gset_new(
+      BLI_ghashutil_ptrhash, BLI_ghashutil_ptrcmp, "GPUNodeGraph.used_libraries");
+  material->refcount = 1;
+
+  /* Construct the material graph by adding and linking the necessary GPU material nodes. */
+  construct_function_cb(thunk, material);
+
+  /* Create and initialize the texture storing color bands used by Ramp and Curve nodes. */
+  gpu_material_ramp_texture_build(material);
+
+  /* Lookup an existing pass in the cache or generate a new one. */
+  material->pass = GPU_generate_pass(material, &material->graph, generate_code_function_cb, thunk);
+
+  /* The pass already exists in the pass cache but its shader already failed to compile. */
+  if (material->pass == NULL) {
+    material->status = GPU_MAT_FAILED;
+    gpu_node_graph_free(&material->graph);
+    return material;
+  }
+
+  /* The pass already exists in the pass cache and its shader is already compiled. */
+  GPUShader *shader = GPU_pass_shader_get(material->pass);
+  if (shader != NULL) {
+    material->status = GPU_MAT_SUCCESS;
+    gpu_node_graph_free_nodes(&material->graph);
+    return material;
+  }
+
+  /* The material was created successfully but still needs to be compiled. */
+  material->status = GPU_MAT_CREATED;
+  return material;
+}