Workbench: Shadows

Initial review of the shard shadows in the workbench engine.

Speed optimizations like transform feedback are not implemented yet. I first want this part to be reviewed and merged.

@fclem please check the note in drw_stencil_set it was holding back nequal == 0 as by default DST.stencil_mask was set to 0. questioin is should we remove the whole check or not.

Also I am still looking for a better name (or split the enum) for DRW_STATE_STENCIL_DEPTH_FAIL_INCR_DECR_WRAP

Reviewers: fclem

Reviewed By: fclem

Tags: #code_quest

Differential Revision: https://developer.blender.org/D3198

1 files changed, 14 insertions, 6 deletions

diff --git a/source/blender/draw/intern/draw_manager_exec.c b/source/blender/draw/intern/draw_manager_exec.c
index 232ae36438e..434c021775a 100644
--- a/source/blender/draw/intern/draw_manager_exec.c
+++ b/source/blender/draw/intern/draw_manager_exec.c
@@ -278,21 +278,27 @@ void drw_state_set(DRWState state)
 		DRWState test;
 		if (CHANGED_ANY_STORE_VAR(
 		        DRW_STATE_WRITE_STENCIL |
-		        DRW_STATE_STENCIL_EQUAL,
+		        DRW_STATE_WRITE_STENCIL_SHADOW |
+		        DRW_STATE_STENCIL_EQUAL |
+		        DRW_STATE_STENCIL_NEQUAL,
 		        test))
 		{
 			if (test) {
 				glEnable(GL_STENCIL_TEST);
-
 				/* Stencil Write */
 				if ((state & DRW_STATE_WRITE_STENCIL) != 0) {
 					glStencilMask(0xFF);
 					glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
 				}
+				else if ((state & DRW_STATE_WRITE_STENCIL_SHADOW) != 0) {
+					glStencilMask(0xFF);
+					glStencilOpSeparate(GL_BACK,  GL_KEEP, GL_INCR_WRAP, GL_KEEP);
+					glStencilOpSeparate(GL_FRONT, GL_KEEP, GL_DECR_WRAP, GL_KEEP);
+				}
 				/* Stencil Test */
-				else if ((state & DRW_STATE_STENCIL_EQUAL) != 0) {
+				else if ((state & (DRW_STATE_STENCIL_EQUAL | DRW_STATE_STENCIL_NEQUAL)) != 0) {
 					glStencilMask(0x00); /* disable write */
-					DST.stencil_mask = 0;
+					DST.stencil_mask = STENCIL_UNDEFINED;
 				}
 				else {
 					BLI_assert(0);
@@ -318,15 +324,17 @@ void drw_state_set(DRWState state)
 static void drw_stencil_set(unsigned int mask)
 {
 	if (DST.stencil_mask != mask) {
+		DST.stencil_mask = mask;
 		/* Stencil Write */
 		if ((DST.state & DRW_STATE_WRITE_STENCIL) != 0) {
 			glStencilFunc(GL_ALWAYS, mask, 0xFF);
-			DST.stencil_mask = mask;
 		}
 		/* Stencil Test */
 		else if ((DST.state & DRW_STATE_STENCIL_EQUAL) != 0) {
 			glStencilFunc(GL_EQUAL, mask, 0xFF);
-			DST.stencil_mask = mask;
+		}
+		else if ((DST.state & DRW_STATE_STENCIL_NEQUAL) != 0) {
+			glStencilFunc(GL_NOTEQUAL, mask, 0xFF);
 		}
 	}
 }