From dbc500ae9f715b57deef27046c37bd2655f482e2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C5=99emysl=20Eric=20Janouch?=
Date: Wed, 3 Nov 2021 12:05:43 +0100
Subject: [PATCH] Improve thumbnail scaling and alignment
Stretch thumbnails by up to half a pixel so that they align nicely.
Make use of pixman's sRGB mode.
---
README.adoc | 4 ++--
fastiv-browser.c | 52 +++++++++++++++++++++++++++++++++++++++++-------
meson.build | 1 +
3 files changed, 48 insertions(+), 9 deletions(-)
diff --git a/README.adoc b/README.adoc
index 5340a7a..bd0584f 100644
--- a/README.adoc
+++ b/README.adoc
@@ -18,8 +18,8 @@ a package with the latest development version from Archlinux's AUR.
Building and Running
--------------------
Build dependencies: Meson, pkg-config +
-Runtime dependencies: gtk+-3.0, shared-mime-info, libpng>=1.5.4, libturbojpeg,
-LibRaw (optional)
+Runtime dependencies: gtk+-3.0, pixman-1, shared-mime-info, libpng>=1.5.4,
+libturbojpeg, LibRaw (optional)
$ git clone --recursive https://git.janouch.name/p/fastiv.git
$ meson builddir
diff --git a/fastiv-browser.c b/fastiv-browser.c
index 41c89ed..ba6d8a3 100644
--- a/fastiv-browser.c
+++ b/fastiv-browser.c
@@ -16,6 +16,7 @@
//
#include
+#include
#include "fastiv-browser.h"
#include "fastiv-io.h"
@@ -145,12 +146,49 @@ fastiv_browser_draw(GtkWidget *widget, cairo_t *cr)
int width = cairo_image_surface_get_width(entry->thumbnail);
int height = cairo_image_surface_get_height(entry->thumbnail);
- double scale = row_height / height;
- if (width * scale > 2 * row_height)
- scale = 2 * row_height / width;
+ double scale_x = 1;
+ double scale_y = 1;
+ if (width > 2 * height) {
+ scale_x = 2 * row_height / width;
+ scale_y = round(scale_x * height) / height;
+ } else {
+ scale_y = row_height / height;
+ scale_x = round(scale_y * width) / width;
+ }
- int projected_width = round(scale * width);
- int projected_height = round(scale * height);
+ int projected_width = round(scale_x * width);
+ int projected_height = round(scale_y * height);
+ cairo_surface_t *scaled = cairo_image_surface_create(
+ CAIRO_FORMAT_ARGB32, projected_width, projected_height);
+
+ // pixman can take gamma into account when scaling, unlike Cairo.
+ struct pixman_f_transform xform_floating;
+ struct pixman_transform xform;
+
+ pixman_image_t *src = pixman_image_create_bits(
+ PIXMAN_a8r8g8b8_sRGB, width, height,
+ (uint32_t *) cairo_image_surface_get_data(entry->thumbnail),
+ cairo_image_surface_get_stride(entry->thumbnail));
+ pixman_image_t *dest = pixman_image_create_bits(
+ PIXMAN_a8r8g8b8_sRGB,
+ cairo_image_surface_get_width(scaled),
+ cairo_image_surface_get_height(scaled),
+ (uint32_t *) cairo_image_surface_get_data(scaled),
+ cairo_image_surface_get_stride(scaled));
+
+ pixman_f_transform_init_scale(&xform_floating, scale_x, scale_y);
+ pixman_f_transform_invert(&xform_floating, &xform_floating);
+ pixman_transform_from_pixman_f_transform(&xform, &xform_floating);
+ pixman_image_set_transform(src, &xform);
+ pixman_image_set_filter(src, PIXMAN_FILTER_BILINEAR, NULL, 0);
+ pixman_image_set_repeat(src, PIXMAN_REPEAT_PAD);
+
+ pixman_image_composite(PIXMAN_OP_SRC, src, NULL, dest, 0, 0, 0, 0, 0, 0,
+ projected_width, projected_height);
+ pixman_image_unref(src);
+ pixman_image_unref(dest);
+
+ cairo_surface_mark_dirty(scaled);
if (occupied_width != 0 &&
occupied_width + projected_width > allocation.width) {
@@ -160,8 +198,8 @@ fastiv_browser_draw(GtkWidget *widget, cairo_t *cr)
cairo_save(cr);
cairo_translate(cr, occupied_width, y + row_height - projected_height);
- cairo_scale(cr, scale, scale);
- cairo_set_source_surface(cr, entry->thumbnail, 0, 0);
+ cairo_set_source_surface(cr, scaled, 0, 0);
+ cairo_surface_destroy(scaled);
cairo_paint(cr);
cairo_restore(cr);
diff --git a/meson.build b/meson.build
index ec0741a..12d79ee 100644
--- a/meson.build
+++ b/meson.build
@@ -6,6 +6,7 @@ dependencies = [
dependency('gtk+-3.0'),
dependency('libturbojpeg'),
dependency('libpng', version : '>=1.5.4'),
+ dependency('pixman-1'),
libraw,
meson.get_compiler('c').find_library('m', required : false),
]