Merge pull request #2825 from RyanDwyer/fractional-scale-pixel-leaks

Fix pixel leaks when using fractional scaling
This commit is contained in:
Drew DeVault 2018-10-12 23:12:56 +02:00 committed by GitHub
commit b80cf982ae
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GPG key ID: 4AEE18F83AFDEB23
2 changed files with 89 additions and 88 deletions

View file

@ -223,11 +223,15 @@ void output_drag_icons_for_each_surface(struct sway_output *output,
} }
} }
static int scale_length(int length, int offset, float scale) {
return round((offset + length) * scale) - round(offset * scale);
}
static void scale_box(struct wlr_box *box, float scale) { static void scale_box(struct wlr_box *box, float scale) {
box->x *= scale; box->width = scale_length(box->width, box->x, scale);
box->y *= scale; box->height = scale_length(box->height, box->y, scale);
box->width *= scale; box->x = round(box->x * scale);
box->height *= scale; box->y = round(box->y * scale);
} }
struct sway_workspace *output_get_active_workspace(struct sway_output *output) { struct sway_workspace *output_get_active_workspace(struct sway_output *output) {

View file

@ -33,11 +33,27 @@ struct render_data {
float alpha; float alpha;
}; };
/**
* Apply scale to a width or height.
*
* One does not simply multiply the width by the scale. We allow fractional
* scaling, which means the resulting scaled width might be a decimal.
* So we round it.
*
* But even this can produce undesirable results depending on the X or Y offset
* of the box. For example, with a scale of 1.5, a box with width=1 should not
* scale to 2px if its X coordinate is 1, because the X coordinate would have
* scaled to 2px.
*/
static int scale_length(int length, int offset, float scale) {
return round((offset + length) * scale) - round(offset * scale);
}
static void scale_box(struct wlr_box *box, float scale) { static void scale_box(struct wlr_box *box, float scale) {
box->x *= scale; box->width = scale_length(box->width, box->x, scale);
box->y *= scale; box->height = scale_length(box->height, box->y, scale);
box->width *= scale; box->x = round(box->x * scale);
box->height *= scale; box->y = round(box->y * scale);
} }
static void scissor_output(struct wlr_output *wlr_output, static void scissor_output(struct wlr_output *wlr_output,
@ -392,14 +408,23 @@ static void render_titlebar(struct sway_output *output,
render_rect(output->wlr_output, output_damage, &box, color); render_rect(output->wlr_output, output_damage, &box, color);
// Single pixel right edge // Single pixel right edge
box.x = (x + width - TITLEBAR_BORDER_THICKNESS) * output_scale; box.x = x + width - TITLEBAR_BORDER_THICKNESS;
box.y = y + TITLEBAR_BORDER_THICKNESS;
box.width = TITLEBAR_BORDER_THICKNESS;
box.height =
container_titlebar_height() - TITLEBAR_BORDER_THICKNESS * 2;
scale_box(&box, output_scale);
render_rect(output->wlr_output, output_damage, &box, color); render_rect(output->wlr_output, output_damage, &box, color);
} }
size_t inner_width = width - TITLEBAR_H_PADDING * 2; size_t inner_width = width - TITLEBAR_H_PADDING * 2;
int bg_y = y + TITLEBAR_BORDER_THICKNESS;
int ob_bg_height = scale_length(
(TITLEBAR_V_PADDING - TITLEBAR_BORDER_THICKNESS) * 2 +
config->font_height, bg_y, output_scale);
// Marks // Marks
size_t marks_ob_width = 0; // output-buffer-local int marks_ob_width = 0; // output-buffer-local
if (config->show_marks && marks_texture) { if (config->show_marks && marks_texture) {
struct wlr_box texture_box; struct wlr_box texture_box;
wlr_texture_get_size(marks_texture, wlr_texture_get_size(marks_texture,
@ -408,15 +433,14 @@ static void render_titlebar(struct sway_output *output,
// The marks texture might be shorter than the config->font_height, in // The marks texture might be shorter than the config->font_height, in
// which case we need to pad it as evenly as possible above and below. // which case we need to pad it as evenly as possible above and below.
int ob_padding_total = config->font_height * output_scale - int ob_padding_total = ob_bg_height - texture_box.height;
texture_box.height; int ob_padding_above = floor(ob_padding_total / 2.0);
int ob_padding_above = floor(ob_padding_total / 2); int ob_padding_below = ceil(ob_padding_total / 2.0);
int ob_padding_below = ceil(ob_padding_total / 2);
// Render texture // Render texture
texture_box.x = (x - output_x + width - TITLEBAR_H_PADDING) texture_box.x = round((x - output_x + width - TITLEBAR_H_PADDING)
* output_scale - texture_box.width; * output_scale) - texture_box.width;
texture_box.y = (y - output_y + TITLEBAR_V_PADDING) * output_scale + texture_box.y = round((bg_y - output_y) * output_scale) +
ob_padding_above; ob_padding_above;
float matrix[9]; float matrix[9];
@ -431,29 +455,18 @@ static void render_titlebar(struct sway_output *output,
&texture_box, matrix, con->alpha); &texture_box, matrix, con->alpha);
// Padding above // Padding above
if (ob_padding_above > 0) { memcpy(&color, colors->background, sizeof(float) * 4);
memcpy(&color, colors->background, sizeof(float) * 4); premultiply_alpha(color, con->alpha);
premultiply_alpha(color, con->alpha); box.x = texture_box.x + round(output_x * output_scale);
box.x = (x + width - TITLEBAR_H_PADDING) * output_scale - box.y = round((y + TITLEBAR_BORDER_THICKNESS) * output_scale);
texture_box.width; box.width = texture_box.width;
box.y = (y + TITLEBAR_V_PADDING) * output_scale; box.height = ob_padding_above;
box.width = texture_box.width; render_rect(output->wlr_output, output_damage, &box, color);
box.height = ob_padding_above;
render_rect(output->wlr_output, output_damage, &box, color);
}
// Padding below // Padding below
if (ob_padding_below > 0) { box.y += ob_padding_above + texture_box.height;
memcpy(&color, colors->background, sizeof(float) * 4); box.height = ob_padding_below;
premultiply_alpha(color, con->alpha); render_rect(output->wlr_output, output_damage, &box, color);
box.x = (x + width - TITLEBAR_H_PADDING) * output_scale -
texture_box.width;
box.y = (y + TITLEBAR_V_PADDING) * output_scale +
ob_padding_above + texture_box.height;
box.width = texture_box.width;
box.height = ob_padding_below;
render_rect(output->wlr_output, output_damage, &box, color);
}
} }
// Title text // Title text
@ -466,89 +479,73 @@ static void render_titlebar(struct sway_output *output,
// The title texture might be shorter than the config->font_height, // The title texture might be shorter than the config->font_height,
// in which case we need to pad it above and below. // in which case we need to pad it above and below.
int ob_padding_above = (config->font_baseline - con->title_baseline) int ob_padding_above = round((config->font_baseline -
* output_scale; con->title_baseline + TITLEBAR_V_PADDING -
int ob_padding_below = (config->font_height - con->title_height) TITLEBAR_BORDER_THICKNESS) * output_scale);
* output_scale - ob_padding_above; int ob_padding_below = ob_bg_height - ob_padding_above -
texture_box.height;
// Render texture // Render texture
texture_box.x = (x - output_x + TITLEBAR_H_PADDING) * output_scale; texture_box.x =
texture_box.y = (y - output_y + TITLEBAR_V_PADDING) * output_scale + round((x - output_x + TITLEBAR_H_PADDING) * output_scale);
ob_padding_above; texture_box.y =
round((bg_y - output_y) * output_scale) + ob_padding_above;
float matrix[9]; float matrix[9];
wlr_matrix_project_box(matrix, &texture_box, wlr_matrix_project_box(matrix, &texture_box,
WL_OUTPUT_TRANSFORM_NORMAL, WL_OUTPUT_TRANSFORM_NORMAL,
0.0, output->wlr_output->transform_matrix); 0.0, output->wlr_output->transform_matrix);
if (inner_width * output_scale - marks_ob_width < texture_box.width) { int inner_x = x - output_x + TITLEBAR_H_PADDING;
texture_box.width = inner_width * output_scale - marks_ob_width; int ob_inner_width = scale_length(inner_width, inner_x, output_scale);
if (ob_inner_width - marks_ob_width < texture_box.width) {
texture_box.width = ob_inner_width - marks_ob_width;
} }
render_texture(output->wlr_output, output_damage, title_texture, render_texture(output->wlr_output, output_damage, title_texture,
&texture_box, matrix, con->alpha); &texture_box, matrix, con->alpha);
// Padding above // Padding above
if (ob_padding_above > 0) { memcpy(&color, colors->background, sizeof(float) * 4);
memcpy(&color, colors->background, sizeof(float) * 4); premultiply_alpha(color, con->alpha);
premultiply_alpha(color, con->alpha); box.x = texture_box.x + round(output_x * output_scale);
box.x = (x + TITLEBAR_H_PADDING) * output_scale; box.y = round((y + TITLEBAR_BORDER_THICKNESS) * output_scale);
box.y = (y + TITLEBAR_V_PADDING) * output_scale; box.width = texture_box.width;
box.width = texture_box.width; box.height = ob_padding_above;
box.height = ob_padding_above; render_rect(output->wlr_output, output_damage, &box, color);
render_rect(output->wlr_output, output_damage, &box, color);
}
// Padding below // Padding below
if (ob_padding_below > 0) { box.y += ob_padding_above + texture_box.height;
memcpy(&color, colors->background, sizeof(float) * 4); box.height = ob_padding_below;
premultiply_alpha(color, con->alpha); render_rect(output->wlr_output, output_damage, &box, color);
box.x = (x + TITLEBAR_H_PADDING) * output_scale;
box.y = (y + TITLEBAR_V_PADDING) * output_scale +
ob_padding_above + texture_box.height;
box.width = texture_box.width;
box.height = ob_padding_below;
render_rect(output->wlr_output, output_damage, &box, color);
}
} }
// Padding above title
memcpy(&color, colors->background, sizeof(float) * 4);
premultiply_alpha(color, con->alpha);
box.x = x + (layout == L_TABBED) * TITLEBAR_BORDER_THICKNESS;
box.y = y + TITLEBAR_BORDER_THICKNESS;
box.width = width - (layout == L_TABBED) * TITLEBAR_BORDER_THICKNESS * 2;
box.height = TITLEBAR_V_PADDING - TITLEBAR_BORDER_THICKNESS;
scale_box(&box, output_scale);
render_rect(output->wlr_output, output_damage, &box, color);
// Padding below title
box.y = (y + TITLEBAR_V_PADDING + config->font_height) * output_scale;
render_rect(output->wlr_output, output_damage, &box, color);
// Filler between title and marks // Filler between title and marks
box.width = inner_width * output_scale - title_ob_width - marks_ob_width; box.width =
round(inner_width * output_scale) - title_ob_width - marks_ob_width;
if (box.width > 0) { if (box.width > 0) {
box.x = (x + TITLEBAR_H_PADDING) * output_scale + title_ob_width; box.x = round((x + TITLEBAR_H_PADDING) * output_scale) + title_ob_width;
box.y = (y + TITLEBAR_V_PADDING) * output_scale; box.y = round(bg_y * output_scale);
box.height = config->font_height * output_scale; box.height = ob_bg_height;
render_rect(output->wlr_output, output_damage, &box, color); render_rect(output->wlr_output, output_damage, &box, color);
} }
// Padding left of title // Padding left of title
left_offset = (layout == L_TABBED) * TITLEBAR_BORDER_THICKNESS; left_offset = (layout == L_TABBED) * TITLEBAR_BORDER_THICKNESS;
box.x = x + left_offset; box.x = x + left_offset;
box.y = y + TITLEBAR_V_PADDING; box.y = y + TITLEBAR_BORDER_THICKNESS;
box.width = TITLEBAR_H_PADDING - left_offset; box.width = TITLEBAR_H_PADDING - left_offset;
box.height = config->font_height; box.height = (TITLEBAR_V_PADDING - TITLEBAR_BORDER_THICKNESS) * 2 +
config->font_height;
scale_box(&box, output_scale); scale_box(&box, output_scale);
render_rect(output->wlr_output, output_damage, &box, color); render_rect(output->wlr_output, output_damage, &box, color);
// Padding right of marks // Padding right of marks
right_offset = (layout == L_TABBED) * TITLEBAR_BORDER_THICKNESS; right_offset = (layout == L_TABBED) * TITLEBAR_BORDER_THICKNESS;
box.x = x + width - TITLEBAR_H_PADDING; box.x = x + width - TITLEBAR_H_PADDING;
box.y = y + TITLEBAR_V_PADDING; box.y = y + TITLEBAR_BORDER_THICKNESS;
box.width = TITLEBAR_H_PADDING - right_offset; box.width = TITLEBAR_H_PADDING - right_offset;
box.height = config->font_height; box.height = (TITLEBAR_V_PADDING - TITLEBAR_BORDER_THICKNESS) * 2 +
config->font_height;
scale_box(&box, output_scale); scale_box(&box, output_scale);
render_rect(output->wlr_output, output_damage, &box, color); render_rect(output->wlr_output, output_damage, &box, color);