LineArt: Shadow and related functionalities.

This patch includes the full shadow functionality for LineArt:

- Light contour and cast shadow lines.
- Lit/shaded region selection.
- Enclosed light/shadow shape calculation.
- Silhouette/anti-silhouette selection.
- Intersection priority based on shadow edge identifier.

Reviewed By: Sebastian Parborg (zeddb)

Differential Revision: https://developer.blender.org/D15109

1 files changed, 33 insertions, 9 deletions

diff --git a/source/blender/makesdna/DNA_gpencil_modifier_types.h b/source/blender/makesdna/DNA_gpencil_modifier_types.h
index 56963bae3e1..f6a54308efc 100644
--- a/source/blender/makesdna/DNA_gpencil_modifier_types.h
+++ b/source/blender/makesdna/DNA_gpencil_modifier_types.h
@@ -998,6 +998,18 @@ typedef enum eLineartGpencilModifierSource {
   LRT_SOURCE_SCENE = 2,
 } eLineartGpencilModifierSource;
 
+typedef enum eLineartGpencilModifierShadowFilter {
+  LRT_SHADOW_FILTER_NONE = 0,
+  LRT_SHADOW_FILTER_LIT = 1,
+  LRT_SHADOW_FILTER_SHADED = 2,
+} eLineartGpencilModifierShadowFilter;
+
+typedef enum eLineartGpencilModifierSilhouetteFilter {
+  LRT_SILHOUETTE_FILTER_NONE = 0,
+  LRT_SILHOUETTE_FILTER_GROUP = (1 << 0),
+  LRT_SILHOUETTE_FILTER_INDIVIDUAL = (1 << 1),
+} eLineartGpencilModifierSilhouetteFilter;
+
 /* This enum is for modifier internal state only. */
 typedef enum eLineArtGPencilModifierFlags {
   /* These two moved to #eLineartMainFlags to keep consistent with flag variable purpose. */
@@ -1008,6 +1020,7 @@ typedef enum eLineArtGPencilModifierFlags {
   LRT_GPENCIL_USE_CACHE = (1 << 4),
   LRT_GPENCIL_OFFSET_TOWARDS_CUSTOM_CAMERA = (1 << 5),
   LRT_GPENCIL_INVERT_COLLECTION = (1 << 6),
+  LRT_GPENCIL_INVERT_SILHOUETTE_FILTER = (1 << 7),
 } eLineArtGPencilModifierFlags;
 
 typedef enum eLineartGpencilMaskSwitches {
@@ -1024,8 +1037,7 @@ struct LineartCache;
 typedef struct LineartGpencilModifierData {
   GpencilModifierData modifier;
 
-  /** Line type enable flags, bits in #eLineartEdgeFlag. */
-  short edge_types;
+  uint16_t edge_types; /* line type enable flags, bits in eLineartEdgeFlag */
 
   /** Object or Collection, from #eLineartGpencilModifierSource. */
   char source_type;
@@ -1035,6 +1047,7 @@ typedef struct LineartGpencilModifierData {
   short level_end;
 
   struct Object *source_camera;
+  struct Object *light_contour_object;
 
   struct Object *source_object;
   struct Collection *source_collection;
@@ -1049,14 +1062,19 @@ typedef struct LineartGpencilModifierData {
   char source_vertex_group[64];
   char vgname[64];
 
-  /**
-   * Camera focal length is divided by `1 + overscan`, before calculation, which give a wider FOV,
-   * this doesn't change coordinates range internally (-1, 1), but makes the calculated frame
+  /* Camera focal length is divided by (1 + overscan), before caluclation, which give a wider FOV,
+   * this doesn't change coordinates range internally (-1, 1), but makes the caluclated frame
    * bigger than actual output. This is for the easier shifting calculation. A value of 0.5 means
-   * the "internal" focal length become 2/3 of the actual camera.
-   */
+   * the "internal" focal length become 2/3 of the actual camera. */
   float overscan;
 
+  /* Values for point light and directional (sun) light. */
+  /* For point light, fov always gonna be 120 deg horizontal, with 3 "cameras" covering 360 deg. */
+  float shadow_camera_fov;
+  float shadow_camera_size;
+  float shadow_camera_near;
+  float shadow_camera_far;
+
   float opacity;
   short thickness;
 
@@ -1064,7 +1082,9 @@ typedef struct LineartGpencilModifierData {
   unsigned char material_mask_bits;
   unsigned char intersection_mask;
 
-  char _pad[3];
+  unsigned char shadow_selection;
+  unsigned char silhouette_selection;
+  char _pad[1];
 
   /** `0..1` range for cosine angle */
   float crease_threshold;
@@ -1078,7 +1098,7 @@ typedef struct LineartGpencilModifierData {
   /* CPU mode */
   float chaining_image_threshold;
 
-  /* Ported from SceneLineArt flags. */
+  /* eLineartMainFlags, for one time calculation. */
   int calculation_flags;
 
   /* #eLineArtGPencilModifierFlags, modifier internal state. */
@@ -1095,6 +1115,10 @@ typedef struct LineartGpencilModifierData {
   char level_start_override;
   char level_end_override;
   short edge_types_override;
+  char shadow_selection_override;
+  char shadow_use_silhouette_override;
+
+  char _pad2[6];
 
   struct LineartCache *cache;
   /* Keep a pointer to the render buffer so we can call destroy from ModifierData. */