From d96acedcdbab4e8c0ce54d7a3c5c28334557adbd Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C5=99emysl=20Janouch?= Date: Thu, 10 Feb 2011 06:03:41 +0100 Subject: Speed up drawing of the grid. --- liblogdiag/ld-canvas.c | 59 +++++++++++++++++++++++++++++++++++--------------- 1 file changed, 41 insertions(+), 18 deletions(-) diff --git a/liblogdiag/ld-canvas.c b/liblogdiag/ld-canvas.c index f89cbfd..f568f5f 100644 --- a/liblogdiag/ld-canvas.c +++ b/liblogdiag/ld-canvas.c @@ -216,6 +216,7 @@ static gdouble ld_canvas_get_scale_in_px (LdCanvas *self); static void ld_canvas_color_set (LdCanvasColor *color, gdouble r, gdouble g, gdouble b, gdouble a); static void ld_canvas_color_apply (LdCanvasColor *color, cairo_t *cr); +static guint32 ld_canvas_color_to_cairo_argb (LdCanvasColor *color); static gdouble point_to_line_segment_distance (const LdPoint *point, const LdPoint *p1, const LdPoint *p2); @@ -997,6 +998,15 @@ ld_canvas_color_apply (LdCanvasColor *color, cairo_t *cr) cairo_set_source_rgba (cr, color->r, color->g, color->b, color->a); } +static guint32 +ld_canvas_color_to_cairo_argb (LdCanvasColor *color) +{ + return (guint) (color->a * 255) << 24 + | (guint) (color->r * color->a * 255) << 16 + | (guint) (color->g * color->a * 255) << 8 + | (guint) (color->b * color->a * 255); +} + static gdouble point_to_line_segment_distance (const LdPoint *point, const LdPoint *p1, const LdPoint *p2) @@ -1998,7 +2008,10 @@ draw_grid (GtkWidget *widget, DrawData *data) gint grid_factor; gdouble x_init, y_init; gdouble x, y; - gdouble x_round, y_round; + cairo_surface_t *grid_surface; + gint stride; + unsigned char *pixels; + guint32 color; grid_step = data->scale; grid_factor = 1; @@ -2008,9 +2021,13 @@ draw_grid (GtkWidget *widget, DrawData *data) grid_factor *= 5; } - ld_canvas_color_apply (COLOR_GET (data->self, COLOR_GRID), data->cr); - cairo_set_line_width (data->cr, 1); - cairo_set_line_cap (data->cr, CAIRO_LINE_CAP_ROUND); + /* Paint manually on our own raster surface for speed. */ + stride = cairo_format_stride_for_width + (CAIRO_FORMAT_ARGB32, data->exposed_rect.width); + pixels = g_malloc0 (stride * data->exposed_rect.height); + grid_surface = cairo_image_surface_create_for_data + (pixels, CAIRO_FORMAT_ARGB32, + data->exposed_rect.width, data->exposed_rect.height, stride); /* Get coordinates of the top-left point. */ ld_canvas_widget_to_diagram_coords (data->self, @@ -2024,20 +2041,26 @@ draw_grid (GtkWidget *widget, DrawData *data) ld_canvas_diagram_to_widget_coords (data->self, x_init, y_init, &x_init, &y_init); - /* Iterate over all the points. */ - for (x = x_init; x <= data->exposed_rect.x + data->exposed_rect.width; - x += grid_step) - { - for (y = y_init; y <= data->exposed_rect.y + data->exposed_rect.height; - y += grid_step) - { - x_round = floor (x) + 0.5; - y_round = floor (y) + 0.5; - cairo_move_to (data->cr, x_round, y_round); - cairo_line_to (data->cr, x_round, y_round); - } - } - cairo_stroke (data->cr); + x_init -= data->exposed_rect.x; + y_init -= data->exposed_rect.y; + + while (x_init < 0) + x_init += grid_step; + while (y_init < 0) + y_init += grid_step; + + color = ld_canvas_color_to_cairo_argb (COLOR_GET (data->self, COLOR_GRID)); + + for (x = x_init; x < data->exposed_rect.width; x += grid_step) + for (y = y_init; y < data->exposed_rect.height; y += grid_step) + *((guint32 *) (pixels + stride * (gint) y) + (gint) x) = color; + + cairo_set_source_surface (data->cr, grid_surface, + data->exposed_rect.x, data->exposed_rect.y); + cairo_paint (data->cr); + + cairo_surface_destroy (grid_surface); + g_free (pixels); } static void -- cgit v1.2.3