Refactor view3d offscreen drawing to avoid having multiple boolean arguments

This is fully unreadable to have lots of boolean arguments scattered across the
whole argument list. What does `false, true, true` mean in terms of behavior?

Replace those with bitfield which has advantage of having more human readable
meaning.

7 files changed, 63 insertions, 34 deletions

diff --git a/source/blender/blenkernel/BKE_sequencer.h b/source/blender/blenkernel/BKE_sequencer.h
index 657e99f05d1..66325cee98e 100644
--- a/source/blender/blenkernel/BKE_sequencer.h
+++ b/source/blender/blenkernel/BKE_sequencer.h
@@ -421,11 +421,20 @@ struct Sequence *BKE_sequencer_add_sound_strip(struct bContext *C, ListBase *seq
 struct Sequence *BKE_sequencer_add_movie_strip(struct bContext *C, ListBase *seqbasep, struct SeqLoadInfo *seq_load);
 
 /* view3d draw callback, run when not in background view */
+/* NOTE: Keep in sync with V3D_OFS_* flags. */
+enum {
+    SEQ_OFSDRAW_NONE             = (0),
+    SEQ_OFSDRAW_USE_BACKGROUND   = (1 << 0),
+    SEQ_OFSDRAW_USE_FULL_SAMPLE  = (1 << 1),
+    SEQ_OFSDRAW_USE_GPENCIL      = (1 << 2),
+    SEQ_OFSDRAW_USE_SOLID_TEX    = (1 << 2),
+};
+
 typedef struct ImBuf *(*SequencerDrawView)(
-        struct Scene *, struct Object *, int, int,
-        unsigned int, int, bool, bool, bool,
-        int, int, bool, const char *,
-        struct GPUFX *, struct GPUOffScreen *, char[256]);
+        struct Scene *scene, struct Object *camera, int width, int height,
+        unsigned int flag, unsigned int draw_flags, int drawtype, int alpha_mode,
+        int samples, const char *viewname,
+        struct GPUFX *fx, struct GPUOffScreen *ofs, char err_out[256]);
 extern SequencerDrawView sequencer_view3d_cb;
 
 /* copy/paste */
diff --git a/source/blender/blenkernel/intern/sequencer.c b/source/blender/blenkernel/intern/sequencer.c
index 9b0db300e6d..592091b057f 100644
--- a/source/blender/blenkernel/intern/sequencer.c
+++ b/source/blender/blenkernel/intern/sequencer.c
@@ -3295,11 +3295,17 @@ static ImBuf *seq_render_scene_strip(const SeqRenderData *context, Sequence *seq
 
 	if ((sequencer_view3d_cb && do_seq_gl && camera) && is_thread_main) {
 		char err_out[256] = "unknown";
-		int width = (scene->r.xsch * scene->r.size) / 100;
-		int height = (scene->r.ysch * scene->r.size) / 100;
+		const int width = (scene->r.xsch * scene->r.size) / 100;
+		const int height = (scene->r.ysch * scene->r.size) / 100;
 		const bool use_background = (scene->r.alphamode == R_ADDSKY);
 		const char *viewname = BKE_scene_multiview_render_view_name_get(&scene->r, context->view_id);
 
+		unsigned int draw_flags = SEQ_OFSDRAW_NONE;
+		draw_flags |= (use_gpencil) ? SEQ_OFSDRAW_USE_GPENCIL : 0;
+		draw_flags |= (use_background) ? SEQ_OFSDRAW_USE_BACKGROUND : 0;
+		draw_flags |= (context->gpu_full_samples) ? SEQ_OFSDRAW_USE_FULL_SAMPLE : 0;
+		draw_flags |= (context->scene->r.seq_flag & R_SEQ_SOLID_TEX) ? SEQ_OFSDRAW_USE_SOLID_TEX : 0;
+
 		/* for old scene this can be uninitialized,
 		 * should probably be added to do_versions at some point if the functionality stays */
 		if (context->scene->r.seq_prev_type == 0)
@@ -3309,11 +3315,8 @@ static ImBuf *seq_render_scene_strip(const SeqRenderData *context, Sequence *seq
 		BKE_scene_update_for_newframe(context->eval_ctx, context->bmain, scene, scene->lay);
 		ibuf = sequencer_view3d_cb(
 		        /* set for OpenGL render (NULL when scrubbing) */
-		        scene, camera, width, height, IB_rect,
-		        context->scene->r.seq_prev_type,
-		        (context->scene->r.seq_flag & R_SEQ_SOLID_TEX) != 0,
-		        use_gpencil, use_background, scene->r.alphamode,
-		        context->gpu_samples, context->gpu_full_samples, viewname,
+		        scene, camera, width, height, IB_rect, draw_flags, context->scene->r.seq_prev_type,
+		        scene->r.alphamode, context->gpu_samples, viewname,
 		        context->gpu_fx, context->gpu_offscreen, err_out);
 		if (ibuf == NULL) {
 			fprintf(stderr, "seq_render_scene_strip failed to get opengl buffer: %s\n", err_out);
diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index 85fb0ee4447..0a87360e58d 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -367,15 +367,26 @@ void ED_view3d_draw_setup_view(
         struct wmWindow *win, struct Scene *scene, struct ARegion *ar, struct View3D *v3d,
         float viewmat[4][4], float winmat[4][4], const struct rcti *rect);
 
+enum {
+	V3D_OFSDRAW_NONE             = (0),
+
+	V3D_OFSDRAW_USE_BACKGROUND   = (1 << 0),
+	V3D_OFSDRAW_USE_FULL_SAMPLE  = (1 << 1),
+
+	/* Only works with ED_view3d_draw_offscreen_imbuf_simple(). */
+	V3D_OFSDRAW_USE_GPENCIL      = (1 << 2),
+	V3D_OFSDRAW_USE_SOLID_TEX    = (1 << 2),
+};
+
 struct ImBuf *ED_view3d_draw_offscreen_imbuf(
         struct Scene *scene, struct View3D *v3d, struct ARegion *ar, int sizex, int sizey,
-        unsigned int flag, bool draw_background,
-        int alpha_mode, int samples, bool full_samples, const char *viewname,
+        unsigned int flag, unsigned int draw_flags,
+        int alpha_mode, int samples, const char *viewname,
         struct GPUFX *fx, struct GPUOffScreen *ofs, char err_out[256]);
 struct ImBuf *ED_view3d_draw_offscreen_imbuf_simple(
         struct Scene *scene, struct Object *camera, int width, int height,
-        unsigned int flag, int drawtype, bool use_solid_tex, bool use_gpencil, bool draw_background,
-        int alpha_mode, int samples, bool full_samples, const char *viewname,
+        unsigned int flag, unsigned int draw_flags, int drawtype, int alpha_mode,
+        int samples, const char *viewname,
         struct GPUFX *fx, struct GPUOffScreen *ofs, char err_out[256]);
 
 struct Base *ED_view3d_give_base_under_cursor(struct bContext *C, const int mval[2]);
diff --git a/source/blender/editors/render/render_opengl.c b/source/blender/editors/render/render_opengl.c
index a27026878e1..a2d34ffefa8 100644
--- a/source/blender/editors/render/render_opengl.c
+++ b/source/blender/editors/render/render_opengl.c
@@ -353,11 +353,15 @@ static void screen_opengl_render_doit(OGLRender *oglrender, RenderResult *rr)
 		ImBuf *ibuf_view;
 		const int alpha_mode = (draw_sky) ? R_ADDSKY : R_ALPHAPREMUL;
 
+		unsigned int draw_flags = V3D_OFSDRAW_NONE;
+		draw_flags |= (oglrender->ofs_full_samples) ? V3D_OFSDRAW_USE_FULL_SAMPLE : 0;
+
 		if (view_context) {
+			draw_flags |= (draw_bgpic) ? V3D_OFSDRAW_USE_BACKGROUND : 0;
+
 			ibuf_view = ED_view3d_draw_offscreen_imbuf(
 			       scene, v3d, ar, sizex, sizey,
-			       IB_rect, draw_bgpic,
-			       alpha_mode, oglrender->ofs_samples, oglrender->ofs_full_samples, viewname,
+			       IB_rect, draw_flags, alpha_mode, oglrender->ofs_samples, viewname,
 			       oglrender->fx, oglrender->ofs, err_out);
 
 			/* for stamp only */
@@ -366,10 +370,11 @@ static void screen_opengl_render_doit(OGLRender *oglrender, RenderResult *rr)
 			}
 		}
 		else {
+			draw_flags |= (V3D_OFSDRAW_USE_GPENCIL | V3D_OFSDRAW_USE_BACKGROUND);
 			ibuf_view = ED_view3d_draw_offscreen_imbuf_simple(
 			        scene, scene->camera, oglrender->sizex, oglrender->sizey,
-			        IB_rect, OB_SOLID, false, true, true,
-			        alpha_mode, oglrender->ofs_samples, oglrender->ofs_full_samples, viewname,
+			        IB_rect, draw_flags, OB_SOLID,
+			        alpha_mode, oglrender->ofs_samples, viewname,
 			        oglrender->fx, oglrender->ofs, err_out);
 			camera = scene->camera;
 		}
diff --git a/source/blender/editors/sculpt_paint/paint_image_proj.c b/source/blender/editors/sculpt_paint/paint_image_proj.c
index ae6dbbf440c..6fa45f1932a 100644
--- a/source/blender/editors/sculpt_paint/paint_image_proj.c
+++ b/source/blender/editors/sculpt_paint/paint_image_proj.c
@@ -5460,7 +5460,7 @@ static int texture_paint_image_from_view_exec(bContext *C, wmOperator *op)
 
 	ibuf = ED_view3d_draw_offscreen_imbuf(
 	        scene, CTX_wm_view3d(C), CTX_wm_region(C),
-	        w, h, IB_rect, false, R_ALPHAPREMUL, 0, false, NULL,
+	        w, h, IB_rect, V3D_OFSDRAW_NONE, R_ALPHAPREMUL, 0, NULL,
 	        NULL, NULL, err_out);
 	if (!ibuf) {
 		/* Mostly happens when OpenGL offscreen buffer was failed to create, */
diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 56508ea989a..8fd38d6a8de 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -3286,14 +3286,16 @@ void ED_view3d_draw_setup_view(
  */
 ImBuf *ED_view3d_draw_offscreen_imbuf(
         Scene *scene, View3D *v3d, ARegion *ar, int sizex, int sizey,
-        unsigned int flag, bool draw_background,
-        int alpha_mode, int samples, bool full_samples, const char *viewname,
+        unsigned int flag, unsigned int draw_flags,
+        int alpha_mode, int samples, const char *viewname,
         /* output vars */
         GPUFX *fx, GPUOffScreen *ofs, char err_out[256])
 {
 	RegionView3D *rv3d = ar->regiondata;
 	ImBuf *ibuf;
 	const bool draw_sky = (alpha_mode == R_ADDSKY);
+	const bool draw_background = (draw_flags & V3D_OFSDRAW_USE_BACKGROUND);
+	const bool use_full_sample = (draw_flags & V3D_OFSDRAW_USE_FULL_SAMPLE);
 
 	/* view state */
 	GPUFXSettings fx_settings = v3d->fx_settings;
@@ -3309,7 +3311,7 @@ ImBuf *ED_view3d_draw_offscreen_imbuf(
 
 	if (own_ofs) {
 		/* bind */
-		ofs = GPU_offscreen_create(sizex, sizey, full_samples ? 0 : samples, err_out);
+		ofs = GPU_offscreen_create(sizex, sizey, use_full_sample ? 0 : samples, err_out);
 		if (ofs == NULL) {
 			return NULL;
 		}
@@ -3354,7 +3356,7 @@ ImBuf *ED_view3d_draw_offscreen_imbuf(
 		}
 	}
 
-	if ((samples && full_samples) == 0) {
+	if ((samples && use_full_sample) == 0) {
 		/* Single-pass render, common case */
 		ED_view3d_draw_offscreen(
 		        scene, v3d, ar, sizex, sizey, NULL, winmat,
@@ -3454,8 +3456,8 @@ ImBuf *ED_view3d_draw_offscreen_imbuf(
  */
 ImBuf *ED_view3d_draw_offscreen_imbuf_simple(
         Scene *scene, Object *camera, int width, int height,
-        unsigned int flag, int drawtype, bool use_solid_tex, bool use_gpencil, bool draw_background,
-        int alpha_mode, int samples, bool full_samples, const char *viewname,
+        unsigned int flag, unsigned int draw_flags, int drawtype,
+        int alpha_mode, int samples, const char *viewname,
         GPUFX *fx, GPUOffScreen *ofs, char err_out[256])
 {
 	View3D v3d = {NULL};
@@ -3472,13 +3474,13 @@ ImBuf *ED_view3d_draw_offscreen_imbuf_simple(
 	v3d.drawtype = drawtype;
 	v3d.flag2 = V3D_RENDER_OVERRIDE;
 	
-	if (use_gpencil)
+	if (draw_flags & V3D_OFSDRAW_USE_GPENCIL)
 		v3d.flag2 |= V3D_SHOW_GPENCIL;
 
-	if (use_solid_tex)
+	if (draw_flags & V3D_OFSDRAW_USE_SOLID_TEX)
 		v3d.flag2 |= V3D_SOLID_TEX;
 		
-	if (draw_background)
+	if (draw_flags & V3D_OFSDRAW_USE_BACKGROUND)
 		v3d.flag3 |= V3D_SHOW_WORLD;
 
 	rv3d.persp = RV3D_CAMOB;
@@ -3507,9 +3509,8 @@ ImBuf *ED_view3d_draw_offscreen_imbuf_simple(
 	invert_m4_m4(rv3d.persinv, rv3d.viewinv);
 
 	return ED_view3d_draw_offscreen_imbuf(
-	        scene, &v3d, &ar, width, height, flag,
-	        draw_background, alpha_mode, samples, full_samples, viewname,
-	        fx, ofs, err_out);
+	        scene, &v3d, &ar, width, height, flag, draw_flags,
+	        alpha_mode, samples, viewname, fx, ofs, err_out);
 }
 
 
diff --git a/source/blender/windowmanager/intern/wm_files.c b/source/blender/windowmanager/intern/wm_files.c
index 2f6b18cfd3c..57f4219f23f 100644
--- a/source/blender/windowmanager/intern/wm_files.c
+++ b/source/blender/windowmanager/intern/wm_files.c
@@ -1029,14 +1029,14 @@ static ImBuf *blend_file_thumb(Scene *scene, bScreen *screen, BlendThumbnail **t
 		ibuf = ED_view3d_draw_offscreen_imbuf_simple(
 		        scene, scene->camera,
 		        BLEN_THUMB_SIZE * 2, BLEN_THUMB_SIZE * 2,
-		        IB_rect, OB_SOLID, false, false, false, R_ALPHAPREMUL, 0, false, NULL,
+		        IB_rect, OB_SOLID, V3D_OFSDRAW_NONE, R_ALPHAPREMUL, 0, NULL,
 		        NULL, NULL, err_out);
 	}
 	else {
 		ibuf = ED_view3d_draw_offscreen_imbuf(
 		        scene, v3d, ar,
 		        BLEN_THUMB_SIZE * 2, BLEN_THUMB_SIZE * 2,
-		        IB_rect, false, R_ALPHAPREMUL, 0, false, NULL,
+		        IB_rect, V3D_OFSDRAW_NONE, R_ALPHAPREMUL, 0, NULL,
 		        NULL, NULL, err_out);
 	}