From 10ab8b274020a9323413d093c45f13490929fb81 Mon Sep 17 00:00:00 2001 From: Manuel Stoeckl Date: Sat, 14 Jan 2023 14:51:47 -0500 Subject: [PATCH] Estimate buffer size in advance for render_frame The size of the surface used to draw the indicator depends on the extents of the text being drawn on and under the indicator. This commit refactors the `render_frame` function so that the surface size is computed before drawing; before, `render_frame` drew onto a buffer, estimated the size the buffer should have had, and recursively called itself to try again with the estimated size, if necessary. This was done because Cairo's methods to estimate font and text size require that a cairo_t context object and an associated cairo_surface already have been set up. Since the surface size depends on the text size, the natural way to use Cairo would have a circular dependency. In order to compute sizes _before_ the buffer is created, this commit adds a 1x1 surface and a matching `test_cairo` context which is set to the same font and drawing parameters as the buffer that will be created. Font/text extent measurements should give the same results as for the final buffer. --- include/swaylock.h | 2 + main.c | 5 ++ render.c | 220 ++++++++++++++++++++++++--------------------- 3 files changed, 127 insertions(+), 100 deletions(-) diff --git a/include/swaylock.h b/include/swaylock.h index 2d38488..e29a99e 100644 --- a/include/swaylock.h +++ b/include/swaylock.h @@ -86,6 +86,8 @@ struct swaylock_state { struct swaylock_args args; struct swaylock_password password; struct swaylock_xkb xkb; + cairo_surface_t *test_surface; + cairo_t *test_cairo; // used to estimate font/text sizes enum auth_state auth_state; int failed_attempts; bool run_display; diff --git a/main.c b/main.c index d18a48b..e288df5 100644 --- a/main.c +++ b/main.c @@ -1291,6 +1291,9 @@ int main(int argc, char **argv) { return 1; } + state.test_surface = cairo_image_surface_create(CAIRO_FORMAT_RGB24, 1, 1); + state.test_cairo = cairo_create(state.test_surface); + struct swaylock_surface *surface; wl_list_for_each(surface, &state.surfaces, link) { create_surface(surface); @@ -1325,5 +1328,7 @@ int main(int argc, char **argv) { } free(state.args.font); + cairo_destroy(state.test_cairo); + cairo_surface_destroy(state.test_surface); return 0; } diff --git a/render.c b/render.c index fee2a4b..3ce7a80 100644 --- a/render.c +++ b/render.c @@ -68,95 +68,35 @@ void render_frame_background(struct swaylock_surface *surface) { wl_surface_commit(surface->surface); } -void render_frame(struct swaylock_surface *surface) { - struct swaylock_state *state = surface->state; - - int arc_radius = state->args.radius * surface->scale; - int arc_thickness = state->args.thickness * surface->scale; - int buffer_diameter = (arc_radius + arc_thickness) * 2; - - int buffer_width = surface->indicator_width; - int buffer_height = surface->indicator_height; - int new_width = buffer_diameter; - int new_height = buffer_diameter; - - int subsurf_xpos; - int subsurf_ypos; - - // Center the indicator unless overridden by the user - if (state->args.override_indicator_x_position) { - subsurf_xpos = state->args.indicator_x_position - - buffer_width / (2 * surface->scale) + 2 / surface->scale; - } else { - subsurf_xpos = surface->width / 2 - - buffer_width / (2 * surface->scale) + 2 / surface->scale; - } - - if (state->args.override_indicator_y_position) { - subsurf_ypos = state->args.indicator_y_position - - (state->args.radius + state->args.thickness); - } else { - subsurf_ypos = surface->height / 2 - - (state->args.radius + state->args.thickness); - } - - wl_subsurface_set_position(surface->subsurface, subsurf_xpos, subsurf_ypos); - - struct pool_buffer *buffer = get_next_buffer(state->shm, - surface->indicator_buffers, buffer_width, buffer_height); - if (buffer == NULL) { - return; - } - - cairo_t *cairo = buffer->cairo; - cairo_set_antialias(cairo, CAIRO_ANTIALIAS_BEST); +static void configure_font_drawing(cairo_t *cairo, struct swaylock_state *state, + enum wl_output_subpixel subpixel, int arc_radius) { cairo_font_options_t *fo = cairo_font_options_create(); cairo_font_options_set_hint_style(fo, CAIRO_HINT_STYLE_FULL); cairo_font_options_set_antialias(fo, CAIRO_ANTIALIAS_SUBPIXEL); - cairo_font_options_set_subpixel_order(fo, to_cairo_subpixel_order(surface->subpixel)); + cairo_font_options_set_subpixel_order(fo, to_cairo_subpixel_order(subpixel)); + cairo_set_font_options(cairo, fo); + cairo_select_font_face(cairo, state->args.font, + CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL); + if (state->args.font_size > 0) { + cairo_set_font_size(cairo, state->args.font_size); + } else { + cairo_set_font_size(cairo, arc_radius / 3.0f); + } cairo_font_options_destroy(fo); - cairo_identity_matrix(cairo); +} - // Clear - cairo_save(cairo); - cairo_set_source_rgba(cairo, 0, 0, 0, 0); - cairo_set_operator(cairo, CAIRO_OPERATOR_SOURCE); - cairo_paint(cairo); - cairo_restore(cairo); +void render_frame(struct swaylock_surface *surface) { + struct swaylock_state *state = surface->state; - float type_indicator_border_thickness = - TYPE_INDICATOR_BORDER_THICKNESS * surface->scale; + // First, compute the text that will be drawn, if any, since this + // determines the size/positioning of the surface - if (state->args.show_indicator && (state->auth_state != AUTH_STATE_IDLE || - state->args.indicator_idle_visible)) { - // Fill inner circle - cairo_set_line_width(cairo, 0); - cairo_arc(cairo, buffer_width / 2, buffer_diameter / 2, - arc_radius - arc_thickness / 2, 0, 2 * M_PI); - set_color_for_state(cairo, state, &state->args.colors.inside); - cairo_fill_preserve(cairo); - cairo_stroke(cairo); + char attempts[4]; // like i3lock: count no more than 999 + char *text = NULL; + const char *layout_text = NULL; - // Draw ring - cairo_set_line_width(cairo, arc_thickness); - cairo_arc(cairo, buffer_width / 2, buffer_diameter / 2, arc_radius, - 0, 2 * M_PI); - set_color_for_state(cairo, state, &state->args.colors.ring); - cairo_stroke(cairo); - - // Draw a message - char *text = NULL; - const char *layout_text = NULL; - char attempts[4]; // like i3lock: count no more than 999 - set_color_for_state(cairo, state, &state->args.colors.text); - cairo_select_font_face(cairo, state->args.font, - CAIRO_FONT_SLANT_NORMAL, CAIRO_FONT_WEIGHT_NORMAL); - if (state->args.font_size > 0) { - cairo_set_font_size(cairo, state->args.font_size); - } else { - cairo_set_font_size(cairo, arc_radius / 3.0f); - } + if (state->args.show_indicator) { switch (state->auth_state) { case AUTH_STATE_VALIDATING: text = "Verifying"; @@ -201,6 +141,104 @@ void render_frame(struct swaylock_surface *surface) { default: break; } + } + + // Compute the size of the buffer needed + int arc_radius = state->args.radius * surface->scale; + int arc_thickness = state->args.thickness * surface->scale; + int buffer_diameter = (arc_radius + arc_thickness) * 2; + int buffer_width = buffer_diameter; + int buffer_height = buffer_diameter; + + if (text || layout_text) { + cairo_set_antialias(state->test_cairo, CAIRO_ANTIALIAS_BEST); + configure_font_drawing(state->test_cairo, state, surface->subpixel, arc_radius); + + if (text) { + cairo_text_extents_t extents; + cairo_text_extents(state->test_cairo, text, &extents); + if (buffer_width < extents.width) { + buffer_width = extents.width; + } + } + if (layout_text) { + cairo_text_extents_t extents; + cairo_font_extents_t fe; + double box_padding = 4.0 * surface->scale; + cairo_text_extents(state->test_cairo, layout_text, &extents); + cairo_font_extents(state->test_cairo, &fe); + buffer_height += fe.height + 2 * box_padding; + if (buffer_width < extents.width + 2 * box_padding) { + buffer_width = extents.width + 2 * box_padding; + } + } + } + // Ensure buffer size is multiple of buffer scale - required by protocol + buffer_height += surface->scale - (buffer_height % surface->scale); + buffer_width += surface->scale - (buffer_width % surface->scale); + + int subsurf_xpos; + int subsurf_ypos; + + // Center the indicator unless overridden by the user + if (state->args.override_indicator_x_position) { + subsurf_xpos = state->args.indicator_x_position - + buffer_width / (2 * surface->scale) + 2 / surface->scale; + } else { + subsurf_xpos = surface->width / 2 - + buffer_width / (2 * surface->scale) + 2 / surface->scale; + } + + if (state->args.override_indicator_y_position) { + subsurf_ypos = state->args.indicator_y_position - + (state->args.radius + state->args.thickness); + } else { + subsurf_ypos = surface->height / 2 - + (state->args.radius + state->args.thickness); + } + + struct pool_buffer *buffer = get_next_buffer(state->shm, + surface->indicator_buffers, buffer_width, buffer_height); + if (buffer == NULL) { + return; + } + + // Render the buffer + cairo_t *cairo = buffer->cairo; + cairo_set_antialias(cairo, CAIRO_ANTIALIAS_BEST); + + cairo_identity_matrix(cairo); + + // Clear + cairo_save(cairo); + cairo_set_source_rgba(cairo, 0, 0, 0, 0); + cairo_set_operator(cairo, CAIRO_OPERATOR_SOURCE); + cairo_paint(cairo); + cairo_restore(cairo); + + float type_indicator_border_thickness = + TYPE_INDICATOR_BORDER_THICKNESS * surface->scale; + + if (state->args.show_indicator && (state->auth_state != AUTH_STATE_IDLE || + state->args.indicator_idle_visible)) { + // Fill inner circle + cairo_set_line_width(cairo, 0); + cairo_arc(cairo, buffer_width / 2, buffer_diameter / 2, + arc_radius - arc_thickness / 2, 0, 2 * M_PI); + set_color_for_state(cairo, state, &state->args.colors.inside); + cairo_fill_preserve(cairo); + cairo_stroke(cairo); + + // Draw ring + cairo_set_line_width(cairo, arc_thickness); + cairo_arc(cairo, buffer_width / 2, buffer_diameter / 2, arc_radius, + 0, 2 * M_PI); + set_color_for_state(cairo, state, &state->args.colors.ring); + cairo_stroke(cairo); + + // Draw a message + configure_font_drawing(cairo, state, surface->subpixel, arc_radius); + set_color_for_state(cairo, state, &state->args.colors.text); if (text) { cairo_text_extents_t extents; @@ -217,10 +255,6 @@ void render_frame(struct swaylock_surface *surface) { cairo_show_text(cairo, text); cairo_close_path(cairo); cairo_new_sub_path(cairo); - - if (new_width < extents.width) { - new_width = extents.width; - } } // Typing indicator: Highlight random part on keypress @@ -300,25 +334,11 @@ void render_frame(struct swaylock_surface *surface) { cairo_set_source_u32(cairo, state->args.colors.layout_text); cairo_show_text(cairo, layout_text); cairo_new_sub_path(cairo); - - new_height += fe.height + 2 * box_padding; - if (new_width < extents.width + 2 * box_padding) { - new_width = extents.width + 2 * box_padding; - } } } - // Ensure buffer size is multiple of buffer scale - required by protocol - new_height += surface->scale - (new_height % surface->scale); - new_width += surface->scale - (new_width % surface->scale); - - if (buffer_width != new_width || buffer_height != new_height) { - destroy_buffer(buffer); - surface->indicator_width = new_width; - surface->indicator_height = new_height; - render_frame(surface); - return; - } + // Send Wayland requests + wl_subsurface_set_position(surface->subsurface, subsurf_xpos, subsurf_ypos); wl_surface_set_buffer_scale(surface->child, surface->scale); wl_surface_attach(surface->child, buffer->buffer, 0, 0);