Use cairo_push_group() for double buffering in the terminal

Slightly different version of the patch from twied.

diff --git a/clients/terminal.c b/clients/terminal.c
index 9729268..8ede48a 100644 (file)
--- a/clients/terminal.c
+++ b/clients/terminal.c
@@ -894,10 +894,14 @@ terminal_draw_contents(struct terminal *terminal)
        struct glyph_run run;
        cairo_font_extents_t extents;
 
+       surface = window_get_surface(terminal->window);
        window_get_child_allocation(terminal->window, &allocation);
-
-       surface = display_create_surface(terminal->display, &allocation);
        cr = cairo_create(surface);
+       cairo_rectangle(cr, allocation.x, allocation.y,
+                       allocation.width, allocation.height);
+       cairo_clip(cr);
+       cairo_push_group(cr);
+
        cairo_set_operator(cr, CAIRO_OPERATOR_SOURCE);
        terminal_set_color(terminal, cr, terminal->color_scheme->border);
        cairo_paint(cr);
@@ -909,7 +913,8 @@ terminal_draw_contents(struct terminal *terminal)
        top_margin = (allocation.height - terminal->height * extents.height) / 2;
 
        cairo_set_line_width(cr, 1.0);
-
+       cairo_translate(cr, allocation.x + side_margin,
+                       allocation.y + top_margin);
        /* paint the background */
        for (row = 0; row < terminal->height; row++) {
                for (col = 0; col < terminal->width; col++) {
@@ -920,8 +925,8 @@ terminal_draw_contents(struct terminal *terminal)
                                continue;
 
                        terminal_set_color(terminal, cr, attr.attr.bg);
-                       cairo_move_to(cr, side_margin + (col * extents.max_x_advance),
-                             top_margin + (row * extents.height));
+                       cairo_move_to(cr, col * extents.max_x_advance,
+                                     row * extents.height);
                        cairo_rel_line_to(cr, extents.max_x_advance, 0);
                        cairo_rel_line_to(cr, 0, extents.height);
                        cairo_rel_line_to(cr, -extents.max_x_advance, 0);
@@ -942,8 +947,8 @@ terminal_draw_contents(struct terminal *terminal)
 
                        glyph_run_flush(&run, attr);
 
-                       text_x = side_margin + col * extents.max_x_advance;
-                       text_y = top_margin + extents.ascent + row * extents.height;
+                       text_x = col * extents.max_x_advance;
+                       text_y = extents.ascent + row * extents.height;
                        if (attr.attr.a & ATTRMASK_UNDERLINE) {
                                terminal_set_color(terminal, cr, attr.attr.fg);
                                cairo_move_to(cr, text_x, (double)text_y + 1.5);
@@ -962,8 +967,8 @@ terminal_draw_contents(struct terminal *terminal)
                d = 0.5;
 
                cairo_set_line_width(cr, 1);
-               cairo_move_to(cr, side_margin + terminal->column * extents.max_x_advance + d,
-                             top_margin + terminal->row * extents.height + d);
+               cairo_move_to(cr, terminal->column * extents.max_x_advance + d,
+                             terminal->row * extents.height + d);
                cairo_rel_line_to(cr, extents.max_x_advance - 2 * d, 0);
                cairo_rel_line_to(cr, 0, extents.height - 2 * d);
                cairo_rel_line_to(cr, -extents.max_x_advance + 2 * d, 0);
@@ -972,10 +977,9 @@ terminal_draw_contents(struct terminal *terminal)
                cairo_stroke(cr);
        }
 
+       cairo_pop_group_to_source(cr);
+       cairo_paint(cr);
        cairo_destroy(cr);
-
-       window_copy_surface(terminal->window, &allocation, surface);
-
        cairo_surface_destroy(surface);
 }