patch [#21740] Image support for Empty Objects

from Andy Braham (andybraham)

This adds support for empties to reference images and draw in the 3D view.

Modifications from the original patch.
- use an empty draw 'image' type
- use image aspect ratio for non-square-pixels
- when the image is not found, still draw the frame.

4 files changed, 135 insertions, 15 deletions

diff --git a/source/blender/editors/space_view3d/drawobject.c b/source/blender/editors/space_view3d/drawobject.c
index a3a139181d5..ba30aecc9ab 100644
--- a/source/blender/editors/space_view3d/drawobject.c
+++ b/source/blender/editors/space_view3d/drawobject.c
@@ -46,6 +46,7 @@
 #include "DNA_scene_types.h"
 #include "DNA_smoke_types.h"
 #include "DNA_world_types.h"
+#include "DNA_armature_types.h"
 
 #include "BLI_blenlib.h"
 #include "BLI_math.h"
@@ -76,6 +77,9 @@
 
 #include "smoke_API.h"
 
+#include "IMB_imbuf.h"
+#include "IMB_imbuf_types.h"
+
 #include "BIF_gl.h"
 #include "BIF_glutil.h"
 
@@ -515,6 +519,96 @@ void drawaxes(float size, char drawtype)
 	}
 }
 
+
+/* Function to draw an Image on a empty Object */
+static void draw_empty_image(Object *ob)
+{
+	Image *ima = (Image*)ob->data;
+	ImBuf *ibuf = ima ? BKE_image_get_ibuf(ima, NULL) : NULL;
+
+	float scale, ofs_x, ofs_y, sca_x, sca_y;
+	int ima_x, ima_y;
+
+	if(ibuf && (ibuf->rect == NULL) && (ibuf->rect_float != NULL)) {
+		IMB_rect_from_float(ibuf);
+	}
+
+	/* Get the buffer dimensions so we can fallback to fake ones */
+	if(ibuf && ibuf->rect) {
+		ima_x= ibuf->x;
+		ima_y= ibuf->y;
+	}
+	else {
+		ima_x= 1;
+		ima_y= 1;
+	}
+
+	/* Get the image aspect even if the buffer is invalid */
+	if(ima) {
+		if(ima->aspx > ima->aspy) {
+			sca_x= 1.0f;
+			sca_y= ima->aspy / ima->aspx;
+		}
+		else if(ima->aspx < ima->aspy) {
+			sca_x= ima->aspx / ima->aspy;
+			sca_y= 1.0f;
+		}
+		else {
+			sca_x= 1.0f;
+			sca_y= 1.0f;
+		}
+	}
+	else {
+		sca_x= 1.0f;
+		sca_y= 1.0f;
+	}
+
+	/* Calculate the scale center based on objects origin */
+	ofs_x= ob->ima_ofs[0] * ima_x;
+	ofs_y= ob->ima_ofs[1] * ima_y;
+
+	glMatrixMode(GL_MODELVIEW);
+	glPushMatrix();
+
+	/* Make sure we are drawing at the origin */
+	glTranslatef(0.0f,  0.0f,  0.0f);
+
+	/* Calculate Image scale */
+	scale= (ob->empty_drawsize / (float)MAX2(ima_x * sca_x, ima_y * sca_y));
+
+	/* Set the object scale */
+	glScalef(scale * sca_x, scale * sca_y, 1.0f);
+
+	if(ibuf && ibuf->rect) {
+		/* Setup GL params */
+		glEnable(GL_BLEND);
+		glBlendFunc(GL_SRC_ALPHA,  GL_ONE_MINUS_SRC_ALPHA);
+
+		/* Use the object color and alpha */
+		glColor4fv(ob->col);
+
+		/* Draw the Image on the screen */
+		glaDrawPixelsTex(ofs_x, ofs_y, ima_x, ima_y, GL_UNSIGNED_BYTE, ibuf->rect);
+		glPixelTransferf(GL_ALPHA_SCALE, 1.0f);
+
+		glDisable(GL_BLEND);
+	}
+
+	UI_ThemeColor((ob->flag & SELECT) ? TH_SELECT : TH_WIRE);
+
+	/* Calculate the outline vertex positions */
+	glBegin(GL_LINE_LOOP);
+	glVertex2f(ofs_x, ofs_y);
+	glVertex2f(ofs_x + ima_x, ofs_y);
+	glVertex2f(ofs_x + ima_x, ofs_y + ima_y);
+	glVertex2f(ofs_x, ofs_y + ima_y);
+	glEnd();
+
+	/* Reset GL settings */
+	glMatrixMode(GL_MODELVIEW);
+	glPopMatrix();
+}
+
 void drawcircball(int mode, const float cent[3], float rad, float tmat[][4])
 {
 	float vec[3], vx[3], vy[3];
@@ -5954,8 +6048,14 @@ void draw_object(Scene *scene, ARegion *ar, View3D *v3d, Base *base, int flag)
 			break;
 		}
 		case OB_EMPTY:
-			if((v3d->flag2 & V3D_RENDER_OVERRIDE)==0)
-				drawaxes(ob->empty_drawsize, ob->empty_drawtype);
+			if((v3d->flag2 & V3D_RENDER_OVERRIDE)==0) {
+				if (ob->empty_drawtype == OB_EMPTY_IMAGE) {
+					draw_empty_image(ob);
+				}
+				else {
+					drawaxes(ob->empty_drawsize, ob->empty_drawtype);
+				}
+			}
 			break;
 		case OB_LAMP:
 			if((v3d->flag2 & V3D_RENDER_OVERRIDE)==0) {
@@ -6564,7 +6664,12 @@ void draw_object_instance(Scene *scene, View3D *v3d, RegionView3D *rv3d, Object
 			draw_object_mesh_instance(scene, v3d, rv3d, ob, dt, outline);
 			break;
 		case OB_EMPTY:
-			drawaxes(ob->empty_drawsize, ob->empty_drawtype);
+			if (ob->empty_drawtype == OB_EMPTY_IMAGE) {
+				draw_empty_image(ob);
+			}
+			else {
+				drawaxes(ob->empty_drawsize, ob->empty_drawtype);
+			}
 			break;
 	}
 }
diff --git a/source/blender/makesdna/DNA_object_types.h b/source/blender/makesdna/DNA_object_types.h
index c97a1d8fef5..54a885a0860 100644
--- a/source/blender/makesdna/DNA_object_types.h
+++ b/source/blender/makesdna/DNA_object_types.h
@@ -259,6 +259,9 @@ typedef struct Object {
 	ListBase gpulamp;		/* runtime, for lamps only */
 	ListBase pc_ids;
 	ListBase *duplilist;	/* for temporary dupli list storage, only for use by RNA API */
+
+	float ima_ofs[2];		/* offset for image empties */
+	char pad3[8];
 } Object;
 
 /* Warning, this is not used anymore because hooks are now modifiers */
@@ -399,6 +402,7 @@ extern Object workob;
 #define OB_CUBE			5
 #define OB_EMPTY_SPHERE	6
 #define OB_EMPTY_CONE	7
+#define OB_EMPTY_IMAGE	8
 
 /* boundtype */
 #define OB_BOUND_BOX		0
diff --git a/source/blender/makesrna/intern/rna_object.c b/source/blender/makesrna/intern/rna_object.c
index 11e7dd81cb6..d5d7f2917b9 100644
--- a/source/blender/makesrna/intern/rna_object.c
+++ b/source/blender/makesrna/intern/rna_object.c
@@ -307,22 +307,26 @@ static void rna_Base_layer_update(Main *bmain, Scene *scene, PointerRNA *ptr)
 	WM_main_add_notifier(NC_SCENE|ND_LAYER_CONTENT, scene);
 }
 
-static int rna_Object_data_editable(PointerRNA *ptr)
-{
-	Object *ob= (Object*)ptr->data;
-
-	return (ob->type == OB_EMPTY)? 0: PROP_EDITABLE;
-}
-
 static void rna_Object_data_set(PointerRNA *ptr, PointerRNA value)
 {
 	Object *ob= (Object*)ptr->data;
 	ID *id= value.data;
 
-	if(ob->type == OB_EMPTY || id == NULL || ob->mode & OB_MODE_EDIT)
+	if (id == NULL || ob->mode & OB_MODE_EDIT)
 		return;
-	
-	if(ob->type == OB_MESH) {
+
+	if (ob->type == OB_EMPTY) {
+		if(ob->data) {
+			id_us_min((ID*)ob->data);
+			ob->data = NULL;
+		}
+
+		if (id && GS(id->name) == ID_IM) {
+			id_us_plus(id);
+			ob->data = id;
+		}
+	}
+	else if(ob->type == OB_MESH) {
 		set_mesh(ob, (Mesh*)id);
 	}
 	else {
@@ -346,6 +350,7 @@ static StructRNA *rna_Object_data_typef(PointerRNA *ptr)
 	Object *ob= (Object*)ptr->data;
 
 	switch(ob->type) {
+		case OB_EMPTY: return &RNA_Image;
 		case OB_MESH: return &RNA_Mesh;
 		case OB_CURVE: return &RNA_Curve;
 		case OB_SURF: return &RNA_Curve;
@@ -1691,6 +1696,7 @@ static void rna_def_object(BlenderRNA *brna)
 		{OB_CUBE, "CUBE", 0, "Cube", ""},
 		{OB_EMPTY_SPHERE, "SPHERE", 0, "Sphere", ""},
 		{OB_EMPTY_CONE, "CONE", 0, "Cone", ""},
+		{OB_EMPTY_IMAGE, "IMAGE", 0, "Image", ""},
 		{0, NULL, 0, NULL, NULL}};
 	
 	static EnumPropertyItem track_items[] = {
@@ -1758,7 +1764,6 @@ static void rna_def_object(BlenderRNA *brna)
 	prop= RNA_def_property(srna, "data", PROP_POINTER, PROP_NONE);
 	RNA_def_property_struct_type(prop, "ID");
 	RNA_def_property_pointer_funcs(prop, NULL, "rna_Object_data_set", "rna_Object_data_typef", NULL);
-	RNA_def_property_editable_func(prop, "rna_Object_data_editable");
 	RNA_def_property_flag(prop, PROP_EDITABLE|PROP_NEVER_UNLINK);
 	RNA_def_property_ui_text(prop, "Data", "Object data");
 	RNA_def_property_update(prop, 0, "rna_Object_internal_update_data");
@@ -2043,6 +2048,12 @@ static void rna_def_object(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Empty Display Size", "Size of display for empties in the viewport");
 	RNA_def_property_update(prop, NC_OBJECT|ND_DRAW, NULL);
 
+	prop= RNA_def_property(srna, "empty_image_offset", PROP_FLOAT, PROP_DISTANCE);
+	RNA_def_property_float_sdna(prop, NULL, "ima_ofs");
+	RNA_def_property_ui_text(prop, "Origin Offset", "Origin offset distance");
+	RNA_def_property_ui_range(prop, -FLT_MAX, FLT_MAX, 0.1f, 2);
+	RNA_def_property_update(prop, NC_OBJECT|ND_DRAW, NULL);
+
 	/* render */
 	prop= RNA_def_property(srna, "pass_index", PROP_INT, PROP_UNSIGNED);
 	RNA_def_property_int_sdna(prop, NULL, "index");
diff --git a/source/blender/makesrna/intern/rna_ui_api.c b/source/blender/makesrna/intern/rna_ui_api.c
index ae308b9423f..d4ac9880290 100644
--- a/source/blender/makesrna/intern/rna_ui_api.c
+++ b/source/blender/makesrna/intern/rna_ui_api.c
@@ -389,7 +389,7 @@ void RNA_api_ui_layout(StructRNA *srna)
 	RNA_def_function_flag(func, FUNC_USE_CONTEXT);
 	api_ui_item_rna_common(func);
 	parm= RNA_def_pointer(func, "image_user", "ImageUser", "", "");
-	RNA_def_property_flag(parm, PROP_REQUIRED|PROP_RNAPTR);
+	RNA_def_property_flag(parm, PROP_REQUIRED|PROP_RNAPTR|PROP_NEVER_NULL);
 	RNA_def_boolean(func, "compact", 0, "", "Use more compact layout.");
 
 	func= RNA_def_function(srna, "template_list", "uiTemplateList");