New Grease Pencil object for 2D animation

This commit merge the full development done in greasepencil-object branch and include mainly the following features.

- New grease pencil object.
- New drawing engine.
- New grease pencil modes Draw/Sculpt/Edit and Weight Paint.
- New brushes for grease pencil.
- New modifiers for grease pencil.
- New shaders FX.
- New material system (replace old palettes and colors).
- Split of annotations (old grease pencil) and new grease pencil object.
- UI adapted to blender 2.8.

You can get more info here:

https://code.blender.org/2017/12/drawing-2d-animation-in-blender-2-8/
https://code.blender.org/2018/07/grease-pencil-status-update/

This is the result of nearly two years of development and I want thanks firstly the other members of the grease pencil team: Daniel M. Lara, Matias Mendiola and Joshua Leung for their support, ideas and to keep working in the project all the time, without them this project had been impossible.

Also, I want thanks other Blender developers for their help, advices and to be there always to help me, and specially to Clément Foucault, Dalai Felinto, Pablo Vázquez and Campbell Barton.

3 files changed, 43 insertions, 97 deletions

diff --git a/source/blender/editors/render/render_opengl.c b/source/blender/editors/render/render_opengl.c
index 22000bd2a03..ed7950f3993 100644
--- a/source/blender/editors/render/render_opengl.c
+++ b/source/blender/editors/render/render_opengl.c
@@ -329,7 +329,7 @@ static void screen_opengl_render_doit(const bContext *C, OGLRender *oglrender, R
 			GPU_matrix_translate_2f(sizex / 2, sizey / 2);
 
 			G.f |= G_RENDER_OGL;
-			ED_gpencil_draw_ex(scene, gpd, sizex, sizey, scene->r.cfra, SPACE_SEQ);
+			ED_gpencil_draw_ex(rv3d, scene, gpd, sizex, sizey, scene->r.cfra, SPACE_SEQ);
 			G.f &= ~G_RENDER_OGL;
 
 			gp_rect = MEM_mallocN(sizex * sizey * sizeof(unsigned char) * 4, "offscreen rect");
@@ -417,7 +417,7 @@ static void screen_opengl_render_write(OGLRender *oglrender)
 	else printf("OpenGL Render failed to write '%s'\n", name);
 }
 
-static void addAlphaOverFloat(float dest[4], const float source[4])
+static void UNUSED_FUNCTION(addAlphaOverFloat)(float dest[4], const float source[4])
 {
 	/* d = s + (1-alpha_s)d*/
 	float mul;
@@ -431,91 +431,6 @@ static void addAlphaOverFloat(float dest[4], const float source[4])
 
 }
 
-/* add renderlayer and renderpass for each grease pencil layer for using in composition */
-static void add_gpencil_renderpass(const bContext *C, OGLRender *oglrender, RenderResult *rr, RenderView *rv)
-{
-	bGPdata *gpd = oglrender->scene->gpd;
-	Scene *scene = oglrender->scene;
-
-	/* sanity checks */
-	if (gpd == NULL) {
-		return;
-	}
-	if (scene == NULL) {
-		return;
-	}
-	if (BLI_listbase_is_empty(&gpd->layers)) {
-		return;
-	}
-	if (oglrender->v3d != NULL && (oglrender->v3d->flag2 & V3D_SHOW_GPENCIL) == 0) {
-		return;
-	}
-
-	/* save old alpha mode */
-	short oldalphamode = scene->r.alphamode;
-	/* set alpha transparent for gp */
-	scene->r.alphamode = R_ALPHAPREMUL;
-
-	/* saves layer status */
-	short *oldsts = MEM_mallocN(BLI_listbase_count(&gpd->layers) * sizeof(short), "temp_gplayers_flag");
-	int i = 0;
-	for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
-		oldsts[i] = gpl->flag;
-		++i;
-	}
-	/* loop all layers to create separate render */
-	for (bGPDlayer *gpl = gpd->layers.first; gpl; gpl = gpl->next) {
-		/* dont draw layer if hidden */
-		if (gpl->flag & GP_LAYER_HIDE)
-			continue;
-		/* hide all layer except current */
-		for (bGPDlayer *gph = gpd->layers.first; gph; gph = gph->next) {
-			if (gpl != gph) {
-				gph->flag |= GP_LAYER_HIDE;
-			}
-		}
-
-		/* render this gp layer */
-		screen_opengl_render_doit(C, oglrender, rr);
-
-		/* add RendePass composite */
-		RenderPass *rp = RE_create_gp_pass(rr, gpl->info, rv->name);
-
-		/* copy image data from rectf */
-		// XXX: Needs conversion.
-		unsigned char *src = (unsigned char *)RE_RenderViewGetById(rr, oglrender->view_id)->rect32;
-		if (src != NULL) {
-			float *dest = rp->rect;
-
-			int x, y, rectx, recty;
-			rectx = rr->rectx;
-			recty = rr->recty;
-			for (y = 0; y < recty; y++) {
-				for (x = 0; x < rectx; x++) {
-					unsigned char *pixSrc = src + 4 * (rectx * y + x);
-					if (pixSrc[3] > 0) {
-						float *pixDest = dest + 4 * (rectx * y + x);
-						float float_src[4];
-						srgb_to_linearrgb_uchar4(float_src, pixSrc);
-						addAlphaOverFloat(pixDest, float_src);
-					}
-				}
-			}
-		}
-		/* back layer status */
-		i = 0;
-		for (bGPDlayer *gph = gpd->layers.first; gph; gph = gph->next) {
-			gph->flag = oldsts[i];
-			++i;
-		}
-	}
-	/* free memory */
-	MEM_freeN(oldsts);
-
-	/* back default alpha mode */
-	scene->r.alphamode = oldalphamode;
-}
-
 static void screen_opengl_render_apply(const bContext *C, OGLRender *oglrender)
 {
 	RenderResult *rr;
@@ -550,11 +465,6 @@ static void screen_opengl_render_apply(const bContext *C, OGLRender *oglrender)
 		BLI_assert(view_id < oglrender->views_len);
 		RE_SetActiveRenderView(oglrender->re, rv->name);
 		oglrender->view_id = view_id;
-		/* add grease pencil passes. For sequencer, the render does not include renderpasses
-		 * TODO: The sequencer render of grease pencil should be rethought */
-		if (!oglrender->is_sequencer) {
-			add_gpencil_renderpass(C, oglrender, rr, rv);
-		}
 		/* render composite */
 		screen_opengl_render_doit(C, oglrender, rr);
 	}
diff --git a/source/blender/editors/render/render_preview.c b/source/blender/editors/render/render_preview.c
index 3423eedf7ca..069611be35d 100644
--- a/source/blender/editors/render/render_preview.c
+++ b/source/blender/editors/render/render_preview.c
@@ -198,6 +198,7 @@ typedef struct IconPreview {
 
 static Main *G_pr_main = NULL;
 static Main *G_pr_main_cycles = NULL;
+static Main *G_pr_main_grease_pencil = NULL;
 
 #ifndef WITH_HEADLESS
 static Main *load_main_from_memory(const void *blend, int blend_size)
@@ -227,6 +228,7 @@ void ED_preview_ensure_dbase(void)
 	if (!base_initialized) {
 		G_pr_main = load_main_from_memory(datatoc_preview_blend, datatoc_preview_blend_size);
 		G_pr_main_cycles = load_main_from_memory(datatoc_preview_cycles_blend, datatoc_preview_cycles_blend_size);
+		G_pr_main_grease_pencil = load_main_from_memory(datatoc_preview_grease_pencil_blend, datatoc_preview_grease_pencil_blend_size);
 		base_initialized = true;
 	}
 #endif
@@ -245,6 +247,9 @@ void ED_preview_free_dbase(void)
 
 	if (G_pr_main_cycles)
 		BKE_main_free(G_pr_main_cycles);
+
+	if (G_pr_main_grease_pencil)
+		BKE_main_free(G_pr_main_grease_pencil);
 }
 
 static Scene *preview_get_scene(Main *pr_main)
@@ -1102,6 +1107,7 @@ static void icon_preview_startjob_all_sizes(void *customdata, short *stop, short
 		sp->id_copy = ip->id_copy;
 		sp->bmain = ip->bmain;
 		sp->own_id_copy = false;
+		Material *ma = NULL;
 
 		if (is_render) {
 			BLI_assert(ip->id);
@@ -1109,10 +1115,22 @@ static void icon_preview_startjob_all_sizes(void *customdata, short *stop, short
 			 * so don't even think of using cycle's bmain for
 			 * texture icons
 			 */
-			if (GS(ip->id->name) != ID_TE)
-				sp->pr_main = G_pr_main_cycles;
-			else
+			if (GS(ip->id->name) != ID_TE) {
+				/* grease pencil use its own preview file */
+				if (GS(ip->id->name) == ID_MA) {
+					ma = (Material *)ip->id;
+				}
+
+				if ((ma == NULL) || (ma->gp_style == NULL)) {
+					sp->pr_main = G_pr_main_cycles;
+				}
+				else {
+					sp->pr_main = G_pr_main_grease_pencil;
+				}
+			}
+			else {
 				sp->pr_main = G_pr_main;
+			}
 		}
 
 		common_preview_startjob(sp, stop, do_update, progress);
@@ -1274,11 +1292,23 @@ void ED_preview_shader_job(const bContext *C, void *owner, ID *id, ID *parent, M
 	sp->parent = parent;
 	sp->slot = slot;
 	sp->bmain = CTX_data_main(C);
+	Material *ma = NULL;
 
 	/* hardcoded preview .blend for Eevee + Cycles, this should be solved
 	 * once with custom preview .blend path for external engines */
 	if ((method != PR_NODE_RENDER) && id_type != ID_TE) {
-		sp->pr_main = G_pr_main_cycles;
+		/* grease pencil use its own preview file */
+		if (GS(id->name) == ID_MA) {
+			ma = (Material *)id;
+		}
+
+		if ((ma == NULL) || (ma->gp_style == NULL)) {
+			sp->pr_main = G_pr_main_cycles;
+		}
+		else {
+			sp->pr_main = G_pr_main_grease_pencil;
+		}
+
 	}
 	else {
 		sp->pr_main = G_pr_main;
diff --git a/source/blender/editors/render/render_shading.c b/source/blender/editors/render/render_shading.c
index 8077079a9b5..2dd4f328d06 100644
--- a/source/blender/editors/render/render_shading.c
+++ b/source/blender/editors/render/render_shading.c
@@ -469,6 +469,7 @@ static int new_material_exec(bContext *C, wmOperator *UNUSED(op))
 {
 	Material *ma = CTX_data_pointer_get_type(C, "material", &RNA_Material).data;
 	Main *bmain = CTX_data_main(C);
+	Object *ob = CTX_data_active_object(C);
 	PointerRNA ptr, idptr;
 	PropertyRNA *prop;
 
@@ -477,7 +478,12 @@ static int new_material_exec(bContext *C, wmOperator *UNUSED(op))
 		ma = BKE_material_copy(bmain, ma);
 	}
 	else {
-		ma = BKE_material_add(bmain, DATA_("Material"));
+		if ((!ob) || (ob->type != OB_GPENCIL)) {
+			ma = BKE_material_add(bmain, DATA_("Material"));
+		}
+		else {
+			ma = BKE_material_add_gpencil(bmain, DATA_("Material"));
+		}
 		ED_node_shader_default(C, &ma->id);
 		ma->use_nodes = true;
 	}