DRW: Add DRWCommandSetStencil

Now multiple stencils can be set inside a shgroup.

Should not change the previous behavior as all usage of
DRW_shgroup_stencil_mask was done at shgroup creation.

3 files changed, 22 insertions, 9 deletions

diff --git a/source/blender/draw/intern/draw_manager.h b/source/blender/draw/intern/draw_manager.h
index c0fd361dbc2..646eb27a76e 100644
--- a/source/blender/draw/intern/draw_manager.h
+++ b/source/blender/draw/intern/draw_manager.h
@@ -156,6 +156,7 @@ typedef enum {
   DRW_CMD_DRAW_INSTANCE = 2,
   DRW_CMD_DRAW_PROCEDURAL = 3,
   /* Other Commands */
+  DRW_CMD_STENCIL = 14,
   DRW_CMD_SELECTID = 15,
   /* Needs to fit in 4bits */
 } eDRWCommandType;
@@ -189,12 +190,18 @@ typedef struct DRWCommandSetSelectID {
   uint select_id;
 } DRWCommandSetSelectID;
 
+typedef struct DRWCommandSetStencil {
+  uint mask;
+} DRWCommandSetStencil;
+
 typedef union DRWCommand {
   /* Only sortable type */
   DRWCommandDraw draw;
   DRWCommandDrawRange range;
   DRWCommandDrawInstance instance;
   DRWCommandDrawProcedural procedural;
+  /* Stencil */
+  DRWCommandSetStencil stencil;
   /* Select */
   DRWCommandSetSelectID select_id;
 } DRWCommand;
@@ -253,6 +260,8 @@ struct DRWShadingGroup {
   struct DRWUniformChunk *uniforms; /* Uniforms pointers */
   uint32_t uniform_count;           /* Index of next uniform inside DRWUniformChunk. */
 
+  int objectinfo;
+
   struct {
     /* Chunks of draw calls. */
     struct DRWCommandChunk *first, *last;
@@ -262,10 +271,6 @@ struct DRWShadingGroup {
   DRWState state_extra;
   /** State changes for this batch only (and'd with the pass's state) */
   DRWState state_extra_disable;
-  /** Stencil mask to use for stencil test / write operations */
-  uint stencil_mask;
-
-  int objectinfo;
 
   DRWPass *pass_parent; /* backlink to pass we're in */
 };
diff --git a/source/blender/draw/intern/draw_manager_data.c b/source/blender/draw/intern/draw_manager_data.c
index 70a88a7c01c..f6751ff8d88 100644
--- a/source/blender/draw/intern/draw_manager_data.c
+++ b/source/blender/draw/intern/draw_manager_data.c
@@ -665,6 +665,13 @@ static void drw_command_set_select_id(DRWShadingGroup *shgroup, GPUVertBuf *buf,
   cmd->select_id = select_id;
 }
 
+static void drw_command_set_stencil_mask(DRWShadingGroup *shgroup, uint mask)
+{
+  BLI_assert(mask <= 0xFF);
+  DRWCommandSetStencil *cmd = drw_command_create(shgroup, DRW_CMD_STENCIL);
+  cmd->mask = mask;
+}
+
 void DRW_shgroup_call_ex(DRWShadingGroup *shgroup,
                          Object *ob,
                          float (*obmat)[4],
@@ -1084,7 +1091,6 @@ static DRWShadingGroup *drw_shgroup_create_ex(struct GPUShader *shader, DRWPass
   shgroup->shader = shader;
   shgroup->state_extra = 0;
   shgroup->state_extra_disable = ~0x0;
-  shgroup->stencil_mask = 0;
   shgroup->cmd.first = NULL;
   shgroup->cmd.last = NULL;
   shgroup->pass_parent = pass;
@@ -1208,8 +1214,7 @@ void DRW_shgroup_state_disable(DRWShadingGroup *shgroup, DRWState state)
 
 void DRW_shgroup_stencil_mask(DRWShadingGroup *shgroup, uint mask)
 {
-  BLI_assert(mask <= 255);
-  shgroup->stencil_mask = mask;
+  drw_command_set_stencil_mask(shgroup, mask);
 }
 
 bool DRW_shgroup_is_empty(DRWShadingGroup *shgroup)
@@ -1228,7 +1233,8 @@ DRWShadingGroup *DRW_shgroup_get_next(DRWShadingGroup *shgroup)
  * shgroups. */
 uint DRW_shgroup_stencil_mask_get(DRWShadingGroup *shgroup)
 {
-  return shgroup->stencil_mask;
+  /* TODO remove. This is broken. */
+  return 0;
 }
 
 DRWShadingGroup *DRW_shgroup_create_sub(DRWShadingGroup *shgroup)
diff --git a/source/blender/draw/intern/draw_manager_exec.c b/source/blender/draw/intern/draw_manager_exec.c
index ca312c9765a..e4b482764fe 100644
--- a/source/blender/draw/intern/draw_manager_exec.c
+++ b/source/blender/draw/intern/draw_manager_exec.c
@@ -1198,7 +1198,6 @@ static void draw_shgroup(DRWShadingGroup *shgroup, DRWState pass_state)
   release_texture_slots(shader_changed);
 
   drw_state_set((pass_state & shgroup->state_extra_disable) | shgroup->state_extra);
-  drw_stencil_set(shgroup->stencil_mask);
 
   draw_update_uniforms(shgroup, &state, &use_tfeedback);
 
@@ -1225,6 +1224,9 @@ static void draw_shgroup(DRWShadingGroup *shgroup, DRWState pass_state)
       }
 
       switch (cmd_type) {
+        case DRW_CMD_STENCIL:
+          drw_stencil_set(cmd->stencil.mask);
+          break;
         case DRW_CMD_SELECTID:
           state.select_id = cmd->select_id.select_id;
           state.select_buf = cmd->select_id.select_buf;