Eevee: internal support for arbitrary number of volume grids

This has no user visible impact yet since smoke volumes only support a fixed
set of attributes, but will become important with the new volume object.

For GPU shader compilation, volume grids are now handled separately from
image textures. They are somewhere between a vertex attribute and an image
texture, basically an attribute that is stored as a texture.

Differential Revision: https://developer.blender.org/D6952

1 files changed, 24 insertions, 10 deletions

diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index b2658839d67..8a4a88d0663 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -70,6 +70,7 @@ struct GPUMaterial {
 
   const void *engine_type; /* attached engine type */
   int options;             /* to identify shader variations (shadow, probe, world background...) */
+  bool is_volume_shader;   /* is volumetric shader */
 
   /* Nodes */
   GPUNodeGraph graph;
@@ -80,7 +81,8 @@ struct GPUMaterial {
   /* XXX: Should be in Material. But it depends on the output node
    * used and since the output selection is different for GPUMaterial...
    */
-  int domain;
+  bool has_volume_output;
+  bool has_surface_output;
 
   /* Only used by Eevee to know which bsdf are used. */
   int flag;
@@ -109,8 +111,8 @@ struct GPUMaterial {
 };
 
 enum {
-  GPU_DOMAIN_SURFACE = (1 << 0),
-  GPU_DOMAIN_VOLUME = (1 << 1),
+  GPU_USE_SURFACE_OUTPUT = (1 << 0),
+  GPU_USE_VOLUME_OUTPUT = (1 << 1),
 };
 
 /* Functions */
@@ -567,6 +569,11 @@ ListBase GPU_material_textures(GPUMaterial *material)
   return material->graph.textures;
 }
 
+ListBase GPU_material_volume_grids(GPUMaterial *material)
+{
+  return material->graph.volume_grids;
+}
+
 void GPU_material_output_link(GPUMaterial *material, GPUNodeLink *link)
 {
   if (!material->graph.outlink) {
@@ -592,14 +599,19 @@ eGPUMaterialStatus GPU_material_status(GPUMaterial *mat)
 
 /* Code generation */
 
-bool GPU_material_use_domain_surface(GPUMaterial *mat)
+bool GPU_material_has_surface_output(GPUMaterial *mat)
+{
+  return mat->has_surface_output;
+}
+
+bool GPU_material_has_volume_output(GPUMaterial *mat)
 {
-  return (mat->domain & GPU_DOMAIN_SURFACE);
+  return mat->has_volume_output;
 }
 
-bool GPU_material_use_domain_volume(GPUMaterial *mat)
+bool GPU_material_is_volume_shader(GPUMaterial *mat)
 {
-  return (mat->domain & GPU_DOMAIN_VOLUME);
+  return mat->is_volume_shader;
 }
 
 void GPU_material_flag_set(GPUMaterial *mat, eGPUMatFlag flag)
@@ -636,7 +648,8 @@ GPUMaterial *GPU_material_from_nodetree(Scene *scene,
                                         struct bNodeTree *ntree,
                                         ListBase *gpumaterials,
                                         const void *engine_type,
-                                        int options,
+                                        const int options,
+                                        const bool is_volume_shader,
                                         const char *vert_code,
                                         const char *geom_code,
                                         const char *frag_lib,
@@ -655,6 +668,7 @@ GPUMaterial *GPU_material_from_nodetree(Scene *scene,
   mat->scene = scene;
   mat->engine_type = engine_type;
   mat->options = options;
+  mat->is_volume_shader = is_volume_shader;
 #ifndef NDEBUG
   BLI_snprintf(mat->name, sizeof(mat->name), "%s", name);
 #else
@@ -670,8 +684,8 @@ GPUMaterial *GPU_material_from_nodetree(Scene *scene,
 
   gpu_material_ramp_texture_build(mat);
 
-  SET_FLAG_FROM_TEST(mat->domain, has_surface_output, GPU_DOMAIN_SURFACE);
-  SET_FLAG_FROM_TEST(mat->domain, has_volume_output, GPU_DOMAIN_VOLUME);
+  mat->has_surface_output = has_surface_output;
+  mat->has_volume_output = has_volume_output;
 
   if (mat->graph.outlink) {
     /* HACK: this is only for eevee. We add the define here after the nodetree evaluation. */