Overlay Engine: Refactor & Cleanup

This is the unification of all overlays into one overlay engine as described in T65347.

I went over all the code making it more future proof with less hacks and removing old / not relevent parts.

Goals / Acheivements:
- Remove internal shader usage (only drw shaders)
- Remove viewportSize and viewportSizeInv and put them in gloabl ubo
- Fixed some drawing issues: Missing probe option and Missing Alt+B clipping of some shader
- Remove old (legacy) shaders dependancy (not using view UBO).
- Less shader variation (less compilation time at first load and less patching needed for vulkan)
- removed some geom shaders when I could
- Remove static e_data (except shaders storage where it is OK)
- Clear the way to fix some anoying limitations (dithered transparency, background image compositing etc...)
- Wireframe drawing now uses the same batching capabilities as workbench & eevee (indirect drawing).
- Reduced complexity, removed ~3000 Lines of code in draw (also removed a lot of unused shader in GPU).
- Post AA to avoid complexity and cost of MSAA.

Remaining issues:
- ~~Armature edits, overlay toggles, (... others?) are not refreshing viewport after AA is complete~~
- FXAA is not the best for wires, maybe investigate SMAA
- Maybe do something more temporally stable for AA.
- ~~Paint overlays are not working with AA.~~
- ~~infront objects are difficult to select.~~
- ~~the infront wires sometimes goes through they solid counterpart (missing clear maybe?) (toggle overlays on-off when using infront+wireframe overlay in solid shading)~~

Note: I made some decision to change slightly the appearance of some objects to simplify their drawing. Namely the empty arrows end (which is now hollow/wire) and distance points of the cameras/spots being done by lines.

Reviewed By: jbakker

Differential Revision: https://developer.blender.org/D6296

1 files changed, 143 insertions, 0 deletions

diff --git a/source/blender/draw/engines/overlay/overlay_metaball.c b/source/blender/draw/engines/overlay/overlay_metaball.c
new file mode 100644
index 00000000000..a634aed812c
--- /dev/null
+++ b/source/blender/draw/engines/overlay/overlay_metaball.c
@@ -0,0 +1,143 @@
+/*
+ * 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.
+ *
+ * Copyright 2019, Blender Foundation.
+ */
+
+/** \file
+ * \ingroup draw_engine
+ */
+
+#include "DRW_render.h"
+
+#include "DNA_meta_types.h"
+
+#include "BKE_object.h"
+
+#include "DEG_depsgraph_query.h"
+
+#include "ED_mball.h"
+
+#include "overlay_private.h"
+
+void OVERLAY_metaball_cache_init(OVERLAY_Data *vedata)
+{
+  OVERLAY_PassList *psl = vedata->psl;
+  OVERLAY_PrivateData *pd = vedata->stl->pd;
+
+  OVERLAY_InstanceFormats *formats = OVERLAY_shader_instance_formats_get();
+
+#define BUF_INSTANCE DRW_shgroup_call_buffer_instance
+
+  for (int i = 0; i < 2; i++) {
+    DRWState infront_state = (DRW_state_is_select() && (i == 1)) ? DRW_STATE_IN_FRONT_SELECT : 0;
+    DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_WRITE_DEPTH | DRW_STATE_DEPTH_LESS_EQUAL;
+    DRW_PASS_CREATE(psl->metaball_ps[i], state | pd->clipping_state | infront_state);
+
+    /* Reuse armature shader as it's perfect to outline ellipsoids. */
+    struct GPUVertFormat *format = formats->instance_bone;
+    struct GPUShader *sh = OVERLAY_shader_armature_sphere(true);
+    DRWShadingGroup *grp = DRW_shgroup_create(sh, psl->metaball_ps[i]);
+    DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo);
+    pd->mball.handle[i] = BUF_INSTANCE(grp, format, DRW_cache_bone_point_wire_outline_get());
+  }
+}
+
+static void metaball_instance_data_set(
+    BoneInstanceData *data, Object *ob, const float *pos, const float radius, const float color[4])
+{
+  /* Bone point radius is 0.05. Compensate for that. */
+  mul_v3_v3fl(data->mat[0], ob->obmat[0], radius / 0.05f);
+  mul_v3_v3fl(data->mat[1], ob->obmat[1], radius / 0.05f);
+  mul_v3_v3fl(data->mat[2], ob->obmat[2], radius / 0.05f);
+  mul_v3_m4v3(data->mat[3], ob->obmat, pos);
+  /* WATCH: Reminder, alpha is wiresize. */
+  OVERLAY_bone_instance_data_set_color(data, color);
+}
+
+void OVERLAY_edit_metaball_cache_populate(OVERLAY_Data *vedata, Object *ob)
+{
+  const bool do_in_front = (ob->dtx & OB_DRAWXRAY) != 0;
+  const bool is_select = DRW_state_is_select();
+  OVERLAY_PrivateData *pd = vedata->stl->pd;
+  MetaBall *mb = ob->data;
+
+  const float *color;
+  const float col_radius[4] = {0.63f, 0.19f, 0.19f, 1.0f};           /* 0x3030A0 */
+  const float col_radius_select[4] = {0.94f, 0.63f, 0.63f, 1.0f};    /* 0xA0A0F0 */
+  const float col_stiffness[4] = {0.19f, 0.63f, 0.19f, 1.0f};        /* 0x30A030 */
+  const float col_stiffness_select[4] = {0.63f, 0.94f, 0.63f, 1.0f}; /* 0xA0F0A0 */
+
+  int select_id = 0;
+  if (is_select) {
+    const Object *orig_object = DEG_get_original_object(ob);
+    select_id = orig_object->runtime.select_id;
+  }
+
+  LISTBASE_FOREACH (MetaElem *, ml, mb->editelems) {
+    const bool is_selected = (ml->flag & SELECT) != 0;
+    const bool is_scale_radius = (ml->flag & MB_SCALE_RAD) != 0;
+    float stiffness_radius = ml->rad * atanf(ml->s) / (float)M_PI_2;
+    BoneInstanceData instdata;
+
+    if (is_select) {
+      DRW_select_load_id(select_id | MBALLSEL_RADIUS);
+    }
+    color = (is_selected && is_scale_radius) ? col_radius_select : col_radius;
+    metaball_instance_data_set(&instdata, ob, &ml->x, ml->rad, color);
+    DRW_buffer_add_entry_struct(pd->mball.handle[do_in_front], &instdata);
+
+    if (is_select) {
+      DRW_select_load_id(select_id | MBALLSEL_STIFF);
+    }
+    color = (is_selected && !is_scale_radius) ? col_stiffness_select : col_stiffness;
+    metaball_instance_data_set(&instdata, ob, &ml->x, stiffness_radius, color);
+    DRW_buffer_add_entry_struct(pd->mball.handle[do_in_front], &instdata);
+
+    select_id += 0x10000;
+  }
+}
+
+void OVERLAY_metaball_cache_populate(OVERLAY_Data *vedata, Object *ob)
+{
+  const bool do_in_front = (ob->dtx & OB_DRAWXRAY) != 0;
+  OVERLAY_PrivateData *pd = vedata->stl->pd;
+  MetaBall *mb = ob->data;
+  const DRWContextState *draw_ctx = DRW_context_state_get();
+
+  float *color;
+  DRW_object_wire_theme_get(ob, draw_ctx->view_layer, &color);
+
+  LISTBASE_FOREACH (MetaElem *, ml, &mb->elems) {
+    /* Draw radius only. */
+    BoneInstanceData instdata;
+    metaball_instance_data_set(&instdata, ob, &ml->x, ml->rad, color);
+    DRW_buffer_add_entry_struct(pd->mball.handle[do_in_front], &instdata);
+  }
+}
+
+void OVERLAY_metaball_draw(OVERLAY_Data *vedata)
+{
+  OVERLAY_PassList *psl = vedata->psl;
+
+  DRW_draw_pass(psl->metaball_ps[0]);
+}
+
+void OVERLAY_metaball_in_front_draw(OVERLAY_Data *vedata)
+{
+  OVERLAY_PassList *psl = vedata->psl;
+
+  DRW_draw_pass(psl->metaball_ps[1]);
+}