mango request

- optionally display the histogram as lines (not filled areas).
- expand the enum for faster access.
- keep the sample line displayed after doing the line sample (running again clears).

release/scripts/startup/bl_ui/space_image.py

@@ -502,9 +502,12 @@ class IMAGE_PT_view_histogram(Panel):
         layout = self.layout
 
         sima = context.space_data
+        hist = sima.scopes.histogram
 
         layout.template_histogram(sima.scopes, "histogram")
-        layout.prop(sima.scopes.histogram, "mode", icon_only=True)
+        row = layout.row(align=True)
+        row.prop(hist, "mode", icon_only=True, expand=True)
+        row.prop(hist, "show_line", text="")
 
 
 class IMAGE_PT_view_waveform(Panel):
@@ -560,10 +563,13 @@ class IMAGE_PT_sample_line(Panel):
         layout = self.layout
 
         sima = context.space_data
+        hist = sima.sample_histogram
 
         layout.operator("image.sample_line")
         layout.template_histogram(sima, "sample_histogram")
-        layout.prop(sima.sample_histogram, "mode")
+        row = layout.row(align=True)
+        row.prop(hist, "mode", expand=True)
+        row.prop(hist, "show_line", text="")
 
 
 class IMAGE_PT_scope_sample(Panel):

source/blender/editors/interface/interface_draw.c

@@ -658,10 +658,31 @@ static void draw_scope_end(rctf *rect, GLint *scissor)
 }
 
 static void histogram_draw_one(float r, float g, float b, float alpha,
-                               float x, float y, float w, float h, float *data, int res)
+                               float x, float y, float w, float h, float *data, int res, const short is_line)
 {
 	int i;
 	
+	if (is_line) {
+
+		glLineWidth(1.5);
+		glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+		glColor4f(r, g, b, alpha);
+
+		/* curve outline */
+
+		glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+		glEnable(GL_LINE_SMOOTH);
+		glBegin(GL_LINE_STRIP);
+		for (i = 0; i < res; i++) {
+			float x2 = x + i * (w / (float)res);
+			glVertex2f(x2, y + (data[i] * h));
+		}
+		glEnd();
+		glDisable(GL_LINE_SMOOTH);
+
+		glLineWidth(1.0);
+	}
+	else {
 		/* under the curve */
 		glBlendFunc(GL_SRC_ALPHA, GL_ONE);
 		glColor4f(r, g, b, alpha);
@@ -690,6 +711,7 @@ static void histogram_draw_one(float r, float g, float b, float alpha,
 		glEnd();
 		glDisable(GL_LINE_SMOOTH);
 	}
+}
 
 void ui_draw_but_HISTOGRAM(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wcol), rcti *recti)
 {
@@ -698,6 +720,7 @@ void ui_draw_but_HISTOGRAM(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wcol)
 	rctf rect;
 	int i;
 	float w, h;
+	const short is_line = (hist->flag & HISTO_FLAG_LINE) != 0;
 	//float alpha;
 	GLint scissor[4];
 	
@@ -731,14 +754,14 @@ void ui_draw_but_HISTOGRAM(ARegion *ar, uiBut *but, uiWidgetColors *UNUSED(wcol)
 	}
 	
 	if (hist->mode == HISTO_MODE_LUMA)
-		histogram_draw_one(1.0, 1.0, 1.0, 0.75, rect.xmin, rect.ymin, w, h, hist->data_luma, res);
+		histogram_draw_one(1.0, 1.0, 1.0, 0.75, rect.xmin, rect.ymin, w, h, hist->data_luma, res, is_line);
 	else {
 		if (hist->mode == HISTO_MODE_RGB || hist->mode == HISTO_MODE_R)
-			histogram_draw_one(1.0, 0.0, 0.0, 0.75, rect.xmin, rect.ymin, w, h, hist->data_r, res);
+			histogram_draw_one(1.0, 0.0, 0.0, 0.75, rect.xmin, rect.ymin, w, h, hist->data_r, res, is_line);
 		if (hist->mode == HISTO_MODE_RGB || hist->mode == HISTO_MODE_G)
-			histogram_draw_one(0.0, 1.0, 0.0, 0.75, rect.xmin, rect.ymin, w, h, hist->data_g, res);
+			histogram_draw_one(0.0, 1.0, 0.0, 0.75, rect.xmin, rect.ymin, w, h, hist->data_g, res, is_line);
 		if (hist->mode == HISTO_MODE_RGB || hist->mode == HISTO_MODE_B)
-			histogram_draw_one(0.0, 0.0, 1.0, 0.75, rect.xmin, rect.ymin, w, h, hist->data_b, res);
+			histogram_draw_one(0.0, 0.0, 1.0, 0.75, rect.xmin, rect.ymin, w, h, hist->data_b, res, is_line);
 	}
 	
 	/* outline, scale gripper */

source/blender/editors/space_image/image_draw.c

@@ -578,6 +578,28 @@ void draw_image_grease_pencil(bContext *C, short onlyv2d)
 	}
 }
 
+void draw_image_sample_line(SpaceImage *sima)
+{
+	if (sima->sample_line_hist.flag & HISTO_FLAG_SAMPLELINE) {
+		Histogram *hist = &sima->sample_line_hist;
+
+		glBegin(GL_LINES);
+		glColor3ub(0, 0, 0);
+		glVertex2fv(hist->co[0]);
+		glVertex2fv(hist->co[1]);
+		glEnd();
+
+		setlinestyle(1);
+		glBegin(GL_LINES);
+		glColor3ub(255, 255, 255);
+		glVertex2fv(hist->co[0]);
+		glVertex2fv(hist->co[1]);
+		glEnd();
+		setlinestyle(0);
+
+	}
+}
+
 /* XXX becomes WM paint cursor */
 #if 0
 static void draw_image_view_tool(Scene *scene)

source/blender/editors/space_image/image_intern.h

@@ -54,6 +54,7 @@ extern const char *image_context_dir[]; /* doc access */
 /* image_draw.c */
 void draw_image_main(struct SpaceImage *sima, struct ARegion *ar, struct Scene *scene);
 void draw_image_grease_pencil(struct bContext *C, short onlyv2d);
+void draw_image_sample_line(struct SpaceImage *sima);
 
 /* image_ops.c */
 int space_image_main_area_poll(struct bContext *C);

source/blender/editors/space_image/image_ops.c

@@ -2138,6 +2138,13 @@ static int image_sample_line_exec(bContext *C, wmOperator *op)
 	hist->xmax = 1.0f;
 	hist->ymax = 1.0f;
 
+	/* persistent draw */
+	hist->co[0][0] = x1f;
+	hist->co[0][1] = y1f;
+	hist->co[1][0] = x2f;
+	hist->co[1][1] = y2f;
+	hist->flag |= HISTO_FLAG_SAMPLELINE; /* keep drawing the flag after */
+
 	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);
@@ -2180,6 +2187,9 @@ static int image_sample_line_invoke(bContext *C, wmOperator *op, wmEvent *event)
 {
 	SpaceImage *sima = CTX_wm_space_image(C);
 
+	Histogram *hist = &sima->sample_line_hist;
+	hist->flag &= ~HISTO_FLAG_SAMPLELINE;
+
 	if (!ED_space_image_has_buffer(sima))
 		return OPERATOR_CANCELLED;
 	

source/blender/editors/space_image/space_image.c

@@ -828,6 +828,9 @@ static void image_main_area_draw(const bContext *C, ARegion *ar)
 	/* Grease Pencil too (in addition to UV's) */
 	draw_image_grease_pencil((bContext *)C, 1); 
 
+	/* sample line */
+	draw_image_sample_line(sima);
+
 	UI_view2d_view_restore(C);
 
 	/* draw Grease Pencil - screen space only */

source/blender/makesdna/DNA_color_types.h

@@ -102,6 +102,11 @@ typedef enum CurveMappingPreset {
 #define HISTO_MODE_G	3
 #define HISTO_MODE_B	4
 
+enum {
+	HISTO_FLAG_LINE        = (1 << 0),
+	HISTO_FLAG_SAMPLELINE  = (1 << 1)
+};
+
 typedef struct Histogram {
 	int channels;
 	int x_resolution;
@@ -110,8 +115,13 @@ typedef struct Histogram {
 	float data_b[256];
 	float data_luma[256];
 	float xmax, ymax;
-	int mode;
+	short mode;
+	short flag;
 	int height;
+
+	/* sample line only */
+	/* image coords src -> est */
+	float co[2][2];
 } Histogram;
 
 struct ImBuf;

source/blender/makesrna/intern/rna_color.c

@@ -570,11 +570,11 @@ static void rna_def_histogram(BlenderRNA *brna)
 	PropertyRNA *prop;
 	
 	static EnumPropertyItem prop_mode_items[] = {
-		{HISTO_MODE_LUMA, "LUMA", ICON_COLOR, "Luma", ""},
+		{HISTO_MODE_LUMA, "LUMA", 0, "Luma", "Luma"},
-		{HISTO_MODE_RGB, "RGB", ICON_COLOR, "Red Green Blue", ""},
+		{HISTO_MODE_RGB, "RGB", 0, "RGB", "Red Green Blue"},
-		{HISTO_MODE_R, "R", ICON_COLOR, "Red", ""},
+		{HISTO_MODE_R, "R", 0, "R", "Red"},
-		{HISTO_MODE_G, "G", ICON_COLOR, "Green", ""},
+		{HISTO_MODE_G, "G", 0, "G", "Green"},
-		{HISTO_MODE_B, "B", ICON_COLOR, "Blue", ""},
+		{HISTO_MODE_B, "B", 0, "B", "Blue"},
 		{0, NULL, 0, NULL, NULL}
 	};
 		
@@ -586,6 +586,10 @@ static void rna_def_histogram(BlenderRNA *brna)
 	RNA_def_property_enum_items(prop, prop_mode_items);
 	RNA_def_property_ui_text(prop, "Mode", "Channels to display when drawing the histogram");
 
+	prop = RNA_def_property(srna, "show_line", PROP_BOOLEAN, PROP_NONE);
+	RNA_def_property_boolean_sdna(prop, NULL, "flag", HISTO_FLAG_LINE);
+	RNA_def_property_ui_text(prop, "Show Line", "Displays lines rather then filled shapes");
+	RNA_def_property_ui_icon(prop, ICON_IPO, 0);
 }
 
 static void rna_def_scopes(BlenderRNA *brna)