Added a line sampler to the histogram panel in the image space.

Patch #21712 from Xavier Thomas.  
now updates in real time as you pull the line.

6 files changed, 181 insertions, 1 deletions

diff --git a/source/blender/editors/space_image/image_draw.c b/source/blender/editors/space_image/image_draw.c
index 797bb20ddf9..0baa81fc699 100644
--- a/source/blender/editors/space_image/image_draw.c
+++ b/source/blender/editors/space_image/image_draw.c
@@ -158,6 +158,17 @@ void draw_image_info(ARegion *ar, int channels, int x, int y, char *cp, float *f
 	UI_DrawString(10, 10, str);
 }
 
+void draw_image_line(struct ARegion *ar, int x1, int y1, int x2, int y2)
+{
+	glColor3ub(0,0,0);
+	glBegin(GL_LINES);
+	
+	glVertex2i(x1, y1);
+	glVertex2i(x2, y2);
+	
+	glEnd();
+}
+
 /* image drawing */
 
 static void draw_image_grid(ARegion *ar, float zoomx, float zoomy)
diff --git a/source/blender/editors/space_image/image_intern.h b/source/blender/editors/space_image/image_intern.h
index 09bd9edc86d..8c8a8f76710 100644
--- a/source/blender/editors/space_image/image_intern.h
+++ b/source/blender/editors/space_image/image_intern.h
@@ -55,6 +55,7 @@ void IMAGE_OT_toolbox(struct wmOperatorType *ot);
 void draw_image_main(struct SpaceImage *sima, struct ARegion *ar, struct Scene *scene);
 void draw_image_info(struct ARegion *ar, int channels, int x, int y, char *cp, float *fp, int *zp, float *zpf);
 void draw_image_grease_pencil(struct bContext *C, short onlyv2d);
+void draw_image_line(struct ARegion *ar, int x1, int y1, int x2, int y2);
 
 /* image_ops.c */
 int space_image_main_area_poll(struct bContext *C);
@@ -80,6 +81,7 @@ void IMAGE_OT_unpack(struct wmOperatorType *ot);
 void IMAGE_OT_cycle_render_slot(struct wmOperatorType *ot);
 
 void IMAGE_OT_sample(struct wmOperatorType *ot);
+void IMAGE_OT_sample_line(struct wmOperatorType *ot);
 void IMAGE_OT_curves_point_set(struct wmOperatorType *ot);
 
 void IMAGE_OT_record_composite(struct wmOperatorType *ot);
diff --git a/source/blender/editors/space_image/image_ops.c b/source/blender/editors/space_image/image_ops.c
index 3aa766c32d0..386259278df 100644
--- a/source/blender/editors/space_image/image_ops.c
+++ b/source/blender/editors/space_image/image_ops.c
@@ -20,7 +20,7 @@
  * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
  * All rights reserved.
  *
- * Contributor(s): Blender Foundation, 2002-2009
+ * Contributor(s): Blender Foundation, 2002-2009, Xavier Thomas
  *
  * ***** END GPL LICENSE BLOCK *****
  */
@@ -1641,6 +1641,166 @@ void IMAGE_OT_sample(wmOperatorType *ot)
 	ot->flag= OPTYPE_BLOCKING;
 }
 
+/******************** sample line operator ********************/
+typedef struct ImageSampleLineInfo {
+	ARegionType *art;
+	void *draw_handle;
+	int started;
+	int x_start, y_start, x_stop, y_stop;
+} ImageSampleLineInfo;
+
+static void sample_line_draw(const bContext *C, ARegion *ar, void *arg_info)
+{
+	ImageSampleLineInfo *info= arg_info;
+	draw_image_line(ar, info->x_start, info->y_start, info->x_stop, info->y_stop);
+}
+
+static void sample_line_apply(bContext *C, wmOperator *op)
+{
+	SpaceImage *sima= CTX_wm_space_image(C);
+	ImageSampleLineInfo *info= op->customdata;
+	ARegion *ar= CTX_wm_region(C);
+	void *lock;
+	ImBuf *ibuf= ED_space_image_acquire_buffer(sima, &lock);
+	Histogram *hist= &sima->sample_line_hist;
+	float x1f, y1f, x2f, y2f;
+	int x1, y1, x2, y2;
+	int i, x, y;
+	float *fp;
+	unsigned char *cp;
+	
+	if (ibuf == NULL) {
+		ED_space_image_release_buffer(sima, lock);
+		return;
+	}
+	/* hmmmm */
+	if (ibuf->channels < 3) {
+		ED_space_image_release_buffer(sima, lock);
+		return;
+	}
+	
+	UI_view2d_region_to_view(&ar->v2d, info->x_start, info->y_start, &x1f, &y1f);
+	UI_view2d_region_to_view(&ar->v2d, info->x_stop, info->y_stop, &x2f, &y2f);
+	x1= 0.5f+ x1f*ibuf->x;
+	x2= 0.5f+ x2f*ibuf->x;
+	y1= 0.5f+ y1f*ibuf->y;
+	y2= 0.5f+ y2f*ibuf->y;
+	
+	hist->channels = 3;
+	hist->x_resolution = 256;
+	hist->xmax = 1.0f;
+	hist->ymax = 1.0f;
+	
+	for (i=0; i<256; i++) {
+		x= (int)(0.5f + x1 + (float)i*(x2-x1)/255.0f);
+		y= (int)(0.5f + y1 + (float)i*(y2-y1)/255.0f);
+		
+		if (x<0 || y<0 || x>=ibuf->x || y>=ibuf->y) {
+			hist->data_r[i] = hist->data_g[i]= hist->data_b[i] = 0.0f;
+		} else {
+			if (ibuf->rect_float) {
+				fp= (ibuf->rect_float + (ibuf->channels)*(y*ibuf->x + x));
+				hist->data_r[i] = fp[0];
+				hist->data_g[i] = fp[1];
+				hist->data_b[i] = fp[2];
+			}
+			else if (ibuf->rect) {
+				cp= (unsigned char *)(ibuf->rect + y*ibuf->x + x);
+				hist->data_r[i] = (float)cp[0]/255.0f;
+				hist->data_g[i] = (float)cp[1]/255.0f;
+				hist->data_b[i] = (float)cp[2]/255.0f;
+			}
+		}
+	}
+	hist->ok=1;
+	
+	ED_space_image_release_buffer(sima, lock);
+}
+
+static void sample_line_exit(bContext *C, wmOperator *op)
+{
+	ImageSampleLineInfo *info= op->customdata;
+	
+	ED_region_draw_cb_exit(info->art, info->draw_handle);
+	ED_area_tag_redraw(CTX_wm_area(C));
+	MEM_freeN(info);
+}
+
+static int sample_line_invoke(bContext *C, wmOperator *op, wmEvent *event)
+{
+	SpaceImage *sima= CTX_wm_space_image(C);
+	ImageSampleLineInfo *info;
+
+	if(!ED_space_image_has_buffer(sima))
+		return OPERATOR_CANCELLED;
+	
+	info= MEM_callocN(sizeof(ImageSampleLineInfo), "ImageSampleLineInfo");
+	info->started= 0;
+	op->customdata= info;
+
+	WM_event_add_modal_handler(C, op);
+
+	return OPERATOR_RUNNING_MODAL;
+}
+
+static int sample_line_modal(bContext *C, wmOperator *op, wmEvent *event)
+{
+	ImageSampleLineInfo *info= op->customdata;
+	ARegion *ar= CTX_wm_region(C);
+	
+	switch(event->type) {
+		case LEFTMOUSE:
+			if (info->started == 0) {
+				info->x_start = event->mval[0];
+				info->y_start = event->mval[1];
+				info->art= ar->type;
+				info->draw_handle = ED_region_draw_cb_activate(ar->type, sample_line_draw, info, REGION_DRAW_POST_PIXEL);
+				info->started = 1;
+			} else {
+				sample_line_apply(C, op);
+				sample_line_exit(C, op);
+				return OPERATOR_FINISHED;
+			}
+			break;
+		case RIGHTMOUSE: // XXX hardcoded
+		case ESCKEY:
+			sample_line_exit(C, op);
+			return OPERATOR_CANCELLED;
+		case MOUSEMOVE:
+			if (info->started == 1) {
+				info->x_stop = event->mval[0];
+				info->y_stop = event->mval[1];
+				ED_area_tag_redraw(CTX_wm_area(C));
+            sample_line_apply(C, op);
+			}
+			break;
+	}
+
+	return OPERATOR_RUNNING_MODAL;
+}
+
+static int sample_line_cancel(bContext *C, wmOperator *op)
+{
+	sample_line_exit(C, op);
+	return OPERATOR_CANCELLED;
+}
+
+void IMAGE_OT_sample_line(wmOperatorType *ot)
+{
+	/* identifiers */
+	ot->name= "Sample Line";
+	ot->idname= "IMAGE_OT_sample_line";
+	
+	/* api callbacks */
+	ot->invoke= sample_line_invoke;
+	ot->modal= sample_line_modal;
+	ot->cancel= sample_line_cancel;
+	ot->poll= space_image_main_area_poll;
+
+	/* flags */
+	ot->flag= OPTYPE_BLOCKING;
+}
+
 /******************** set curve point operator ********************/
 
 void IMAGE_OT_curves_point_set(wmOperatorType *ot)
diff --git a/source/blender/editors/space_image/space_image.c b/source/blender/editors/space_image/space_image.c
index 3d4d81c836b..8d2e54e0fca 100644
--- a/source/blender/editors/space_image/space_image.c
+++ b/source/blender/editors/space_image/space_image.c
@@ -475,6 +475,7 @@ void image_operatortypes(void)
 	WM_operatortype_append(IMAGE_OT_cycle_render_slot);
 
 	WM_operatortype_append(IMAGE_OT_sample);
+	WM_operatortype_append(IMAGE_OT_sample_line);
 	WM_operatortype_append(IMAGE_OT_curves_point_set);
 
 	WM_operatortype_append(IMAGE_OT_record_composite);
diff --git a/source/blender/makesdna/DNA_space_types.h b/source/blender/makesdna/DNA_space_types.h
index a643e08bbfc..e2c263dd5f1 100644
--- a/source/blender/makesdna/DNA_space_types.h
+++ b/source/blender/makesdna/DNA_space_types.h
@@ -260,6 +260,7 @@ typedef struct SpaceImage {
 	struct bGPdata *gpd;			/* grease pencil data */
 	
 	struct Histogram hist;			/* viewer histogram */
+	struct Histogram sample_line_hist;	/* sample line histogram */
 } SpaceImage;
 
 typedef struct SpaceNla {
diff --git a/source/blender/makesrna/intern/rna_space.c b/source/blender/makesrna/intern/rna_space.c
index 2c9bc945618..2c194fd05f9 100644
--- a/source/blender/makesrna/intern/rna_space.c
+++ b/source/blender/makesrna/intern/rna_space.c
@@ -1188,6 +1188,11 @@ static void rna_def_space_image(BlenderRNA *brna)
 	RNA_def_property_ui_text(prop, "Image Pin", "Display current image regardless of object selection");
 	RNA_def_property_update(prop, NC_SPACE|ND_SPACE_IMAGE, NULL);
 
+	prop= RNA_def_property(srna, "sample_histogram", PROP_POINTER, PROP_NONE);
+	RNA_def_property_pointer_sdna(prop, NULL, "sample_line_hist");
+	RNA_def_property_struct_type(prop, "Histogram");
+	RNA_def_property_ui_text(prop, "Line sample", "Sampled colors along line");
+	
 	/* image draw */
 	prop= RNA_def_property(srna, "draw_repeated", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "flag", SI_DRAW_TILE);