image: only compute when needed

Signed-off-by: Julien Danjou <julien@danjou.info>

draw.c

@@ -598,7 +598,7 @@ draw_image_from_argb_data(draw_context_t *ctx, int x, int y, int w, int h,
 void
 draw_image(draw_context_t *ctx, int x, int y, double ratio, image_t *image)
 {
-    draw_image_from_argb_data(ctx, x, y, image->width, image->height, ratio, image->data);
+    draw_image_from_argb_data(ctx, x, y, image_getwidth(image), image_getheight(image), ratio, image_getdata(image));
 }
 
 /** Rotate a pixmap.

image.c

@@ -75,26 +75,48 @@ image_imlib_load_strerror(Imlib_Load_Error e)
     return "unknown error";
 }
 
-/** Recompute the ARGB32 data from an image.
+/** Get image width.
+ * \param image The image.
+ * \return The image width in pixel.
+ */
+int
+image_getwidth(image_t *image)
+{
+    imlib_context_set_image(image->image);
+    return imlib_image_get_width();
+}
+
+/** Get image height.
+ * \param image The image.
+ * \return The image height in pixel.
+ */
+int
+image_getheight(image_t *image)
+{
+    imlib_context_set_image(image->image);
+    return imlib_image_get_height();
+}
+
+/** Get the ARGB32 data from an image.
  * \param image The image.
  * \return Data.
  */
-static void
+uint8_t *
-image_compute(image_t *image)
+image_getdata(image_t *image)
 {
     int size, i;
     uint32_t *data;
     double alpha;
     uint8_t *dataimg;
 
+    if(image->isupdated)
+        return image->data;
+
     imlib_context_set_image(image->image);
 
     data = imlib_image_get_data_for_reading_only();
 
-    image->width = imlib_image_get_width();
+    size = imlib_image_get_width() * imlib_image_get_height();
-    image->height = imlib_image_get_height();
-
-    size = image->width * image->height;
 
     p_realloc(&image->data, size * 4);
     dataimg = image->data;
@@ -117,6 +139,10 @@ image_compute(image_t *image)
         dataimg[0] = (data[i]         & 0xff) * alpha; /* B */
 #endif
     }
+
+    image->isupdated = true;
+
+    return image->data;
 }
 
 /** Create a new image from ARGB32 data.
@@ -136,7 +162,6 @@ image_new_from_argb32(int width, int height, uint32_t *data)
         imlib_image_set_has_alpha(true);
         image_t *image = image_new(globalconf.L);
         image->image = imimage;
-        image_compute(image);
         return 1;
     }
 
@@ -166,8 +191,6 @@ image_new_from_file(const char *filename)
     image = image_new(globalconf.L);
     image->image = imimage;
 
-    image_compute(image);
-
     return 1;
 }
 
@@ -237,7 +260,7 @@ luaA_image_orientate(lua_State *L)
     imlib_context_set_image(image->image);
     imlib_image_orientate(orientation);
 
-    image_compute(image);
+    image->isupdated = false;
 
     return 0;
 }
@@ -261,8 +284,6 @@ luaA_image_rotate(lua_State *L)
     imlib_context_set_image(image->image);
     new->image = imlib_create_rotated_image(angle);
 
-    image_compute(new);
-
     return 1;
 }
 
@@ -290,8 +311,6 @@ luaA_image_crop(lua_State *L)
     imlib_context_set_image(image->image);
     new->image = imlib_create_cropped_image(x, y, w, h);
 
-    image_compute(new);
-
     return 1;
 }
 
@@ -327,8 +346,6 @@ luaA_image_crop_and_scale(lua_State *L)
                                                    w, h,
                                                    dest_w, dest_h);
 
-    image_compute(new);
-
     return 1;
 }
 
@@ -360,7 +377,7 @@ luaA_image_draw_pixel(lua_State *L)
 
     imlib_context_set_color(color.red, color.green, color.blue, color.alpha);
     imlib_image_draw_pixel(x, y, 1);
-    image_compute(image);
+    image->isupdated = false;
     return 0;
 }
 
@@ -396,7 +413,7 @@ luaA_image_draw_line(lua_State *L)
 
     imlib_context_set_color(color.red, color.green, color.blue, color.alpha);
     imlib_image_draw_line(x1, y1, x2, y2, 0);
-    image_compute(image);
+    image->isupdated = false;
     return 0;
 }
 
@@ -439,7 +456,7 @@ luaA_image_draw_rectangle(lua_State *L)
         imlib_image_draw_rectangle(x, y, width, height);
     else
         imlib_image_fill_rectangle(x, y, width, height);
-    image_compute(image);
+    image->isupdated = false;
     return 0;
 }
 
@@ -530,7 +547,7 @@ luaA_image_draw_rectangle_gradient(lua_State *L)
 
     imlib_free_color_range();
 
-    image_compute(image);
+    image->isupdated = false;
 
     return 0;
 }
@@ -574,7 +591,7 @@ luaA_image_draw_circle(lua_State *L)
         imlib_image_draw_ellipse(x, y, ah, av);
     else
         imlib_image_fill_ellipse(x, y, ah, av);
-    image_compute(image);
+    image->isupdated = false;
     return 0;
 }
 
@@ -629,14 +646,14 @@ luaA_image_insert(lua_State *L)
 
     int xsrc = luaL_optnumber(L, 5, 0);
     int ysrc = luaL_optnumber(L, 6, 0);
-    int wsrc = luaL_optnumber(L, 7, image_source->width);
+    int wsrc = luaL_optnumber(L, 7, image_getwidth(image_source));
-    int hsrc = luaL_optnumber(L, 8, image_source->height);
+    int hsrc = luaL_optnumber(L, 8, image_getheight(image_source));
 
-    int hxoff = luaL_optnumber(L, 9, image_source->width);
+    int hxoff = luaL_optnumber(L, 9, image_getwidth(image_source));
     int hyoff = luaL_optnumber(L, 10, 0);
 
     int vxoff = luaL_optnumber(L, 11, 0);
-    int vyoff = luaL_optnumber(L, 12, image_source->height);
+    int vyoff = luaL_optnumber(L, 12, image_getheight(image_source));
 
     imlib_context_set_image(image_target->image);
 
@@ -649,7 +666,7 @@ luaA_image_insert(lua_State *L)
                                          * is the default */
                                         hxoff, hyoff, vxoff, vyoff);
 
-    image_compute(image_target);
+    image_target->isupdated = false;
 
     return 0;
 }
@@ -675,12 +692,10 @@ luaA_image_index(lua_State *L)
     switch(a_tokenize(attr, len))
     {
       case A_TK_WIDTH:
-        imlib_context_set_image(image->image);
+        lua_pushnumber(L, image_getwidth(image));
-        lua_pushnumber(L, imlib_image_get_width());
         break;
       case A_TK_HEIGHT:
-        imlib_context_set_image(image->image);
+        lua_pushnumber(L, image_getheight(image));
-        lua_pushnumber(L, imlib_image_get_height());
         break;
       case A_TK_ALPHA:
         imlib_context_set_image(image->image);

image.h

@@ -33,17 +33,19 @@ typedef struct
     luaA_ref_array_t refs;
     /** Imlib2 image */
     Imlib_Image image;
-    /** Image width */
-    int width;
-    /** Image height */
-    int height;
     /** Image data */
     uint8_t *data;
+    /** Flag telling if the image is up to date or needs computing before
+     * drawing */
+    bool isupdated;
 } image_t;
 
 LUA_OBJECT_FUNCS(image_t, image, "image")
 
 int image_new_from_argb32(int, int, uint32_t *);
+uint8_t * image_getdata(image_t *);
+int image_getwidth(image_t *);
+int image_getheight(image_t *);
 
 #endif
 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80

widgets/imagebox.c

@@ -40,10 +40,12 @@ imagebox_geometry(widget_t *widget, screen_t *screen, int height, int width)
 
     if(d->image)
     {
+        int iwidth = image_getwidth(d->image);
+        int iheight = image_getheight(d->image);
         if(d->resize)
         {
-            double ratio = (double) height / d->image->height;
+            double ratio = (double) height / iheight;
-            geometry.width = ratio * d->image->width;
+            geometry.width = ratio * iwidth;
             if(geometry.width > width)
             {
                 geometry.width = 0;
@@ -52,9 +54,9 @@ imagebox_geometry(widget_t *widget, screen_t *screen, int height, int width)
             else
                 geometry.height = height;
         }
-        else if(d->image->width <= width)
+        else if(iwidth <= width)
         {
-            geometry.width = d->image->width;
+            geometry.width = iwidth;
             geometry.height = height;
         }
         else
@@ -91,14 +93,15 @@ imagebox_draw(widget_t *widget, draw_context_t *ctx, area_t geometry, wibox_t *p
             draw_rectangle(ctx, geometry, 1.0, true, &d->bg);
 
         int y = geometry.y;
-        double ratio = d->resize ? (double) geometry.height / d->image->height : 1;
+        int iheight = image_getheight(d->image);
+        double ratio = d->resize ? (double) geometry.height / iheight : 1;
         switch(d->valign)
         {
           case AlignBottom:
-            y += geometry.height - d->image->height;
+            y += geometry.height - iheight;
             break;
           case AlignCenter:
-            y += (geometry.height - d->image->height) / 2;
+            y += (geometry.height - iheight) / 2;
             break;
           default:
             break;

widgets/textbox.c

@@ -66,8 +66,10 @@ textbox_geometry(widget_t *widget, screen_t *screen, int height, int width)
         geometry.width = width;
     else if(d->bg_image)
     {
-        double ratio = d->bg_resize ? (double) geometry.height / d->bg_image->height : 1;
+        int bgi_height = image_getheight(d->bg_image);
-        geometry.width = MIN(width, MAX(d->extents.width + d->margin.left + d->margin.right, MAX(d->width, d->bg_image->width * ratio)));
+        int bgi_width = image_getwidth(d->bg_image);
+        double ratio = d->bg_resize ? (double) geometry.height / bgi_height : 1;
+        geometry.width = MIN(width, MAX(d->extents.width + d->margin.left + d->margin.right, MAX(d->width, bgi_width * ratio)));
     }
     else
         geometry.width = MIN(d->extents.width + d->margin.left + d->margin.right, width);
@@ -95,25 +97,27 @@ textbox_draw(widget_t *widget, draw_context_t *ctx, area_t geometry, wibox_t *p)
 
     if(d->bg_image)
     {
-        double ratio = d->bg_resize ? (double) geometry.height / d->bg_image->height : 1;
+        int bgi_height = image_getheight(d->bg_image);
+        int bgi_width = image_getwidth(d->bg_image);
+        double ratio = d->bg_resize ? (double) geometry.height / bgi_height : 1;
         /* check there is enough space to draw the image */
-        if(ratio * d->bg_image->width <= geometry.width)
+        if(ratio * bgi_width <= geometry.width)
         {
             int x = geometry.x;
             int y = geometry.y;
             switch(d->bg_align)
             {
               case AlignCenter:
-                x += (geometry.width - d->bg_image->width * ratio) / 2;
+                x += (geometry.width - bgi_width * ratio) / 2;
                 break;
               case AlignRight:
-                x += geometry.width - d->bg_image->width * ratio;
+                x += geometry.width - bgi_width * ratio;
                 break;
               case AlignBottom:
-                y += geometry.height - d->bg_image->height * ratio;
+                y += geometry.height - bgi_height * ratio;
                 break;
               case AlignMiddle:
-                y += (geometry.height - d->bg_image->height * ratio) / 2;
+                y += (geometry.height - bgi_height * ratio) / 2;
                 break;
               default:
                 break;