Eevee: Lookdev: Cleanup implementation & support for Bloom and TAA

Make Lookdev works with bloom and TAA by rendering it before TAA and fixing
the motion vectors of the lookdev balls.

Rework Lookdev to remove much of its complexity. Use simpler matrices with
more understandable setup code.

1 files changed, 85 insertions, 67 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_lookdev.c b/source/blender/draw/engines/eevee/eevee_lookdev.c
index b000eebb92e..c513873f000 100644
--- a/source/blender/draw/engines/eevee/eevee_lookdev.c
+++ b/source/blender/draw/engines/eevee/eevee_lookdev.c
@@ -24,6 +24,9 @@
 #include "BKE_camera.h"
 #include "BKE_studiolight.h"
 
+#include "BLI_rect.h"
+#include "BLI_rand.h"
+
 #include "DNA_screen_types.h"
 #include "DNA_world_types.h"
 
@@ -62,11 +65,28 @@ void EEVEE_lookdev_cache_init(EEVEE_Data *vedata,
 {
   EEVEE_StorageList *stl = vedata->stl;
   EEVEE_TextureList *txl = vedata->txl;
+  EEVEE_EffectsInfo *effects = stl->effects;
   EEVEE_PrivateData *g_data = stl->g_data;
   const DRWContextState *draw_ctx = DRW_context_state_get();
   View3D *v3d = draw_ctx->v3d;
   Scene *scene = draw_ctx->scene;
 
+  /* Viewport / Ball size. */
+  rcti rect;
+  ED_region_visible_rect(draw_ctx->ar, &rect);
+
+  const int ball_size = max_ii(BLI_rcti_size_x(&rect) * 0.1f, 100.0f) * U.dpi_fac;
+
+  if (ball_size != effects->ball_size || rect.xmax != effects->anchor[0] ||
+      rect.ymin != effects->anchor[1]) {
+    /* If ball size or anchor point moves, reset TAA to avoid ghosting issue.
+     * This needs to happen early because we are changing taa_current_sample. */
+    effects->ball_size = ball_size;
+    effects->anchor[0] = rect.xmax;
+    effects->anchor[1] = rect.ymin;
+    EEVEE_temporal_sampling_reset(vedata);
+  }
+
   if (LOOK_DEV_STUDIO_LIGHT_ENABLED(v3d)) {
     StudioLight *sl = BKE_studiolight_find(v3d->shading.lookdev_light,
                                            STUDIOLIGHT_ORIENTATIONS_MATERIAL_MODE);
@@ -157,56 +177,35 @@ void EEVEE_lookdev_cache_init(EEVEE_Data *vedata,
   }
 }
 
-void EEVEE_lookdev_draw_background(EEVEE_Data *vedata)
+static void eevee_lookdev_apply_taa(const EEVEE_EffectsInfo *effects,
+                                    int ball_size,
+                                    float winmat[4][4])
+{
+  if (DRW_state_is_image_render() || ((effects->enabled_effects & EFFECT_TAA) != 0)) {
+    double ht_point[2];
+    double ht_offset[2] = {0.0, 0.0};
+    uint ht_primes[2] = {2, 3};
+    float ofs[2];
+
+    BLI_halton_2d(ht_primes, ht_offset, effects->taa_current_sample, ht_point);
+    EEVEE_temporal_sampling_offset_calc(ht_point, 1.5f, ofs);
+    winmat[3][0] += ofs[0] / ball_size;
+    winmat[3][1] += ofs[1] / ball_size;
+  }
+}
+
+void EEVEE_lookdev_draw(EEVEE_Data *vedata)
 {
   EEVEE_PassList *psl = vedata->psl;
+  EEVEE_FramebufferList *fbl = vedata->fbl;
   EEVEE_StorageList *stl = ((EEVEE_Data *)vedata)->stl;
   EEVEE_EffectsInfo *effects = stl->effects;
   EEVEE_ViewLayerData *sldata = EEVEE_view_layer_data_ensure();
-  DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get();
 
   const DRWContextState *draw_ctx = DRW_context_state_get();
 
-  if (psl->lookdev_pass && LOOK_DEV_OVERLAY_ENABLED(draw_ctx->v3d)) {
-    DRW_stats_group_start("Look Dev");
-    CameraParams params;
-    BKE_camera_params_init(&params);
-    View3D *v3d = draw_ctx->v3d;
-    RegionView3D *rv3d = draw_ctx->rv3d;
-    ARegion *ar = draw_ctx->ar;
-
-    const float *viewport_size = DRW_viewport_size_get();
-    rcti rect;
-    ED_region_visible_rect(draw_ctx->ar, &rect);
-
-    const float viewport_size_target[2] = {
-        viewport_size[0] / 4,
-        viewport_size[1] / 4,
-    };
-    const int viewport_inset[2] = {
-        max_ii(viewport_size_target[0], 300),
-        max_ii(viewport_size_target[0], 300) / 2, /* intentionally use 'x' here for 'y' value. */
-    };
-
-    /* minimum size for preview spheres viewport */
-    const float aspect[2] = {
-        viewport_inset[0] / viewport_size_target[0],
-        viewport_inset[1] / viewport_size_target[1],
-    };
-
-    BKE_camera_params_from_view3d(&params, draw_ctx->depsgraph, v3d, rv3d);
-    params.is_ortho = true;
-    params.ortho_scale = 3.0f;
-    params.zoom = CAMERA_PARAM_ZOOM_INIT_PERSP;
-    params.offsetx = 0.0f;
-    params.offsety = 0.0f;
-    params.shiftx = 0.0f;
-    params.shifty = 0.0f;
-    params.clip_start = 0.001f;
-    params.clip_end = 20.0f;
-    BKE_camera_params_compute_viewplane(&params, ar->winx, ar->winy, aspect[0], aspect[1]);
-    BKE_camera_params_compute_matrix(&params);
-
+  if (psl->lookdev_diffuse_pass && LOOK_DEV_OVERLAY_ENABLED(draw_ctx->v3d)) {
+    /* Config renderer. */
     EEVEE_CommonUniformBuffer *common = &sldata->common_data;
     common->la_num_light = 0;
     common->prb_num_planar = 0;
@@ -218,34 +217,53 @@ void EEVEE_lookdev_draw_background(EEVEE_Data *vedata)
     DRW_uniformbuffer_update(sldata->common_ubo, common);
 
     /* override matrices */
-    float winmat[4][4];
-    float winmat_inv[4][4];
-    copy_m4_m4(winmat, params.winmat);
-    invert_m4_m4(winmat_inv, winmat);
-    DRW_viewport_matrix_override_set(winmat, DRW_MAT_WIN);
-    DRW_viewport_matrix_override_set(winmat_inv, DRW_MAT_WININV);
-    float viewmat[4][4];
-    DRW_viewport_matrix_get(viewmat, DRW_MAT_VIEW);
-    float persmat[4][4];
-    float persmat_inv[4][4];
-    mul_m4_m4m4(persmat, winmat, viewmat);
-    invert_m4_m4(persmat_inv, persmat);
-    DRW_viewport_matrix_override_set(persmat, DRW_MAT_PERS);
-    DRW_viewport_matrix_override_set(persmat_inv, DRW_MAT_PERSINV);
-
-    GPUFrameBuffer *fb = effects->final_fb;
-    GPU_framebuffer_bind(fb);
-    GPU_framebuffer_viewport_set(
-        fb, rect.xmax - viewport_inset[0], rect.ymin, viewport_inset[0], viewport_inset[1]);
-    DRW_draw_pass(psl->lookdev_pass);
+    DRWMatrixState matstate;
+    unit_m4(matstate.winmat);
+
+    eevee_lookdev_apply_taa(effects, effects->ball_size, matstate.winmat);
+
+    /* "Remove" view matrix location. Leaving only rotation. */
+    DRW_viewport_matrix_get(matstate.viewmat, DRW_MAT_VIEW);
+    zero_v3(matstate.viewmat[3]);
+    mul_m4_m4m4(matstate.persmat, matstate.winmat, matstate.viewmat);
+    invert_m4_m4(matstate.wininv, matstate.winmat);
+    invert_m4_m4(matstate.viewinv, matstate.viewmat);
+    invert_m4_m4(matstate.persinv, matstate.persmat);
+
+    DRW_viewport_matrix_override_set_all(&matstate);
+
+    /* Find the right framebuffers to render to. */
+    GPUFrameBuffer *fb = (effects->target_buffer == fbl->effect_color_fb) ? fbl->main_fb :
+                                                                            fbl->effect_fb;
+
+    DRW_stats_group_start("Look Dev");
 
-    fb = dfbl->depth_only_fb;
     GPU_framebuffer_bind(fb);
-    GPU_framebuffer_viewport_set(
-        fb, rect.xmax - viewport_inset[0], rect.ymin, viewport_inset[0], viewport_inset[1]);
-    DRW_draw_pass(psl->lookdev_pass);
 
-    DRW_viewport_matrix_override_unset_all();
+    const int ball_margin = effects->ball_size / 6.0f;
+    float offset[2] = {0.0f, ball_margin};
+
+    offset[0] = effects->ball_size + ball_margin;
+    GPU_framebuffer_viewport_set(fb,
+                                 effects->anchor[0] - offset[0],
+                                 effects->anchor[1] + offset[1],
+                                 effects->ball_size,
+                                 effects->ball_size);
+
+    DRW_draw_pass(psl->lookdev_diffuse_pass);
+
+    offset[0] = (effects->ball_size + ball_margin) +
+                (ball_margin + effects->ball_size + ball_margin);
+    GPU_framebuffer_viewport_set(fb,
+                                 effects->anchor[0] - offset[0],
+                                 effects->anchor[1] + offset[1],
+                                 effects->ball_size,
+                                 effects->ball_size);
+
+    DRW_draw_pass(psl->lookdev_glossy_pass);
+
     DRW_stats_group_end();
+
+    DRW_viewport_matrix_override_unset_all();
   }
 }