From 6b901399ce128d44f87a653234d34023575d9dc6 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Fri, 19 Aug 2016 21:25:48 -0300
Subject: [PATCH] eeshow/gfx/diff.c (diff_to_canvas): draw caller-supplied
 areas

These are for future highlighting. WIP.
---
 eeshow/gfx/diff.c   | 19 +++++++++----------
 eeshow/gfx/diff.h   | 12 +++++++++++-
 eeshow/gui/render.c |  3 ++-
 3 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/eeshow/gfx/diff.c b/eeshow/gfx/diff.c
index 14247ac..c44f02c 100644
--- a/eeshow/gfx/diff.c
+++ b/eeshow/gfx/diff.c
@@ -47,12 +47,6 @@
 #define	AREA_FILL	0xffd0f0
 
 
-
-struct area {
-	int xa, ya, xb, yb;
-	struct area *next;
-};
-
 struct diff {
 	void *cr_ctx;
 	uint32_t *new_img;
@@ -212,6 +206,7 @@ static void mark_area(struct diff *diff, int x, int y)
 	area->xb = x + diff->frame_radius;
 	area->ya = y - diff->frame_radius;
 	area->yb = y + diff->frame_radius;
+	area->color = AREA_FILL;
 
 	area->next = diff->areas;
 	diff->areas = area;
@@ -265,7 +260,7 @@ static void show_areas(struct diff *diff, uint32_t *a)
 
 	for (area = diff->areas; area; area = area->next)
 		complement_box(diff, a, area->xa, area->ya, area->xb, area->yb,
-		    AREA_FILL);
+		    area->color);
 }
 
 
@@ -317,7 +312,8 @@ static void merge_coord(int pos_a, int pos_b, int dim_a, int dim_b,
 
 
 void diff_to_canvas(cairo_t *cr, int cx, int cy, float scale,
-    struct cro_ctx *old, struct cro_ctx *new)
+    struct cro_ctx *old, struct cro_ctx *new,
+    const struct area *areas)
 {
 	int old_xmin, old_ymin, old_w, old_h;
 	int new_xmin, new_ymin, new_w, new_h;
@@ -378,9 +374,12 @@ void diff_to_canvas(cairo_t *cr, int cx, int cy, float scale,
 	cairo_surface_flush(s);
 	differences(&diff, img_old, img_new);
 	show_areas(&diff, img_old);
-	cairo_surface_mark_dirty(s);
-
 	free_areas(&diff);
+	if (areas) {
+		diff.areas = (struct area *) areas;
+		show_areas(&diff, img_old);
+	}
+	cairo_surface_mark_dirty(s);
 
 	cairo_set_source_surface(cr, s, 0, 0);
 	cairo_paint(cr);
diff --git a/eeshow/gfx/diff.h b/eeshow/gfx/diff.h
index 4042ccc..5d7be8e 100644
--- a/eeshow/gfx/diff.h
+++ b/eeshow/gfx/diff.h
@@ -14,6 +14,8 @@
 #ifndef GFX_DIFF_H
 #define	GFX_DIFF_H
 
+#include <stdint.h>
+
 #include <cairo/cairo.h>
 
 #include "gfx/gfx.h"
@@ -23,7 +25,15 @@
 extern const struct gfx_ops diff_ops;
 
 
+struct area {
+	int xa, ya, xb, yb;
+	uint32_t color;
+	struct area *next;
+};
+
+
 void diff_to_canvas(cairo_t *cr, int cx, int cy, float scale, 
-    struct cro_ctx *old, struct cro_ctx *new);
+    struct cro_ctx *old, struct cro_ctx *new,
+    const struct area *areas);
 
 #endif /* !GFX_DIFF_H */
diff --git a/eeshow/gui/render.c b/eeshow/gui/render.c
index 5d217e2..3fa8fa0 100644
--- a/eeshow/gui/render.c
+++ b/eeshow/gui/render.c
@@ -60,6 +60,7 @@ static inline int cd(int x, float scale)
 	return x * scale;
 }
 
+
 static inline int cx(int x, int xo, float scale)
 {
 	return xo + x * scale;
@@ -109,7 +110,7 @@ static void hack(const struct gui_ctx *ctx, cairo_t *cr)
 	    ctx->old_hist->sheets, ctx->new_hist->sheets, ctx->curr_sheet);
 
 	diff_to_canvas(cr, ctx->x, ctx->y, 1.0 / (1 << ctx->zoom),
-	    old->gfx_ctx, new->gfx_ctx);
+	    old->gfx_ctx, new->gfx_ctx, NULL);
 }