Add a --raw option to read image as raw bytes (#226)

pull/232/head
Martin Dørum 2019-05-20 14:20:55 +02:00 committed by Michael Stapelberg
parent 78a601bf98
commit ebf3428f10
2 changed files with 139 additions and 3 deletions

View File

@ -20,6 +20,8 @@ i3lock \- improved screen locker
.RB [\|\-b\|]
.RB [\|\-i
.IR image.png \|]
.RB [\|\-r
.IR format \|]
.RB [\|\-c
.IR color \|]
.RB [\|\-t\|]
@ -74,6 +76,16 @@ verified or whether it is wrong).
.BI \-i\ path \fR,\ \fB\-\-image= path
Display the given PNG image instead of a blank screen.
.TP
.BI \-r\ format \fR,\ \fB\-\-raw= format
Read the image given by \-\-image as a raw image instead of PNG. The argument is the image's format
as <width>x<height>:<pixfmt>. The supported pixel formats are 'native' and 'rgb'.
The "rgb" pixel format expects a pixel to be three bytes; red, green, and blue.
The "native" pixel format expects a pixel as a 32-bit (4-byte) integer in
the machine's native endianness, with the upper 8 bits unused. Red, green and blue are stored in
the remaining bits, in that order.
Example: \-\-raw=1920x1080:rgb
.TP
.BI \-c\ rrggbb \fR,\ \fB\-\-color= rrggbb
Turn the screen into the given color instead of white. Color must be given in 3-byte

130
i3lock.c
View File

@ -645,6 +645,119 @@ void handle_screen_resize(void) {
redraw_screen();
}
static ssize_t read_raw_image_native(uint32_t *dest, FILE *src, size_t width, size_t height, int pixstride) {
ssize_t count = 0;
for (size_t y = 0; y < height; y++) {
size_t n = fread(&dest[y * pixstride], 1, width * 4, src);
count += n;
if (n < (size_t)(width * 4))
break;
}
return count;
}
static ssize_t read_raw_image_rgb(uint32_t *dest, FILE *src, size_t width, size_t height, int pixstride) {
unsigned char *buf = malloc(width * 3);
if (buf == NULL)
return -1;
ssize_t count = 0;
for (size_t y = 0; y < height; y++) {
size_t n = fread(buf, 1, width * 3, src);
count += n;
if (n < (size_t)(width * 3))
break;
for (size_t x = 0; x < width; ++x) {
int idx = x * 3;
dest[y * pixstride + x] = 0 |
(buf[idx + 0] << 16) |
(buf[idx + 1] << 8) |
(buf[idx + 2]);
}
}
free(buf);
return count;
}
static cairo_surface_t *read_raw_image(const char *image_path, const char *image_raw_format) {
cairo_surface_t *img;
#define RAW_PIXFMT_MAXLEN 6
#define STRINGIFY1(x) #x
#define STRINGIFY(x) STRINGIFY1(x)
/* Parse format as <width>x<height>:<pixfmt> */
char pixfmt[RAW_PIXFMT_MAXLEN + 1];
size_t w, h;
const char *fmt = "%zux%zu:%" STRINGIFY(RAW_PIXFMT_MAXLEN) "s";
if (sscanf(image_raw_format, fmt, &w, &h, pixfmt) != 3) {
fprintf(stderr, "Invalid image format: \"%s\"\n", image_raw_format);
return NULL;
}
#undef RAW_PIXFMT_MAXLEN
#undef STRINGIFY1
#undef STRINGIFY
/* Create image surface */
img = cairo_image_surface_create(CAIRO_FORMAT_RGB24, w, h);
if (cairo_surface_status(img) != CAIRO_STATUS_SUCCESS) {
fprintf(stderr, "Could not create surface: %s\n",
cairo_status_to_string(cairo_surface_status(img)));
return NULL;
}
cairo_surface_flush(img);
/* Use uint32_t* because cairo uses native endianness */
uint32_t *data = (uint32_t *)cairo_image_surface_get_data(img);
const int pixstride = cairo_image_surface_get_stride(img) / 4;
FILE *f = fopen(image_path, "r");
if (f == NULL) {
fprintf(stderr, "Could not open image \"%s\": %s\n",
image_path, strerror(errno));
cairo_surface_destroy(img);
return NULL;
}
/* Read the image, respecting cairo's stride, according to the pixfmt */
ssize_t size, count;
if (strcmp(pixfmt, "native") == 0) {
/* If the pixfmt is 'native', just read each line directly into the buffer */
size = w * h * 4;
count = read_raw_image_native(data, f, w, h, pixstride);
} else if (strcmp(pixfmt, "rgb") == 0) {
/* If the pixfmt is 'rgb', we have to convert it to the native pixfmt */
size = w * h * 3;
count = read_raw_image_rgb(data, f, w, h, pixstride);
} else {
fprintf(stderr, "Unknown raw pixel pixfmt: %s\n", pixfmt);
fclose(f);
cairo_surface_destroy(img);
return NULL;
}
cairo_surface_mark_dirty(img);
if (count < size) {
if (count < 0 || ferror(f)) {
fprintf(stderr, "Failed to read image \"%s\": %s\n",
image_path, strerror(errno));
fclose(f);
cairo_surface_destroy(img);
return NULL;
} else {
/* Print a warning if the file contains less data than expected,
* but don't abort. It's useful to see how the image looks even if it's wrong. */
fprintf(stderr, "Warning: expected to read %zi bytes from \"%s\", read %zi\n",
size, image_path, count);
}
}
fclose(f);
return img;
}
static bool verify_png_image(const char *image_path) {
if (!image_path) {
return false;
@ -867,6 +980,7 @@ int main(int argc, char *argv[]) {
struct passwd *pw;
char *username;
char *image_path = NULL;
char *image_raw_format = NULL;
#ifndef __OpenBSD__
int ret;
struct pam_conv conv = {conv_callback, NULL};
@ -890,6 +1004,7 @@ int main(int argc, char *argv[]) {
{"help", no_argument, NULL, 'h'},
{"no-unlock-indicator", no_argument, NULL, 'u'},
{"image", required_argument, NULL, 'i'},
{"raw", required_argument, NULL, 'r'},
{"tiling", no_argument, NULL, 't'},
{"ignore-empty-password", no_argument, NULL, 'e'},
{"inactivity-timeout", required_argument, NULL, 'I'},
@ -902,7 +1017,7 @@ int main(int argc, char *argv[]) {
if ((username = pw->pw_name) == NULL)
errx(EXIT_FAILURE, "pw->pw_name is NULL.");
char *optstring = "hvnbdc:p:ui:teI:fl";
char *optstring = "hvnbdc:p:ui:r:teI:fl";
while ((o = getopt_long(argc, argv, optstring, longopts, &longoptind)) != -1) {
switch (o) {
case 'v':
@ -935,6 +1050,9 @@ int main(int argc, char *argv[]) {
case 'u':
unlock_indicator = false;
break;
case 'r':
image_raw_format = strdup(optarg);
break;
case 'i':
image_path = strdup(optarg);
break;
@ -969,7 +1087,7 @@ int main(int argc, char *argv[]) {
break;
default:
errx(EXIT_FAILURE, "Syntax: i3lock [-v] [-n] [-b] [-d] [-c color] [-u] [-p win|default]"
" [-i image.png] [-t] [-e] [-I timeout] [-f] [-l]");
" [-i image.png] [-r format] [-t] [-e] [-I timeout] [-f] [-l]");
}
}
@ -1069,7 +1187,11 @@ int main(int argc, char *argv[]) {
xcb_change_window_attributes(conn, screen->root, XCB_CW_EVENT_MASK,
(uint32_t[]){XCB_EVENT_MASK_STRUCTURE_NOTIFY});
if (verify_png_image(image_path)) {
if (image_raw_format != NULL && image_path != NULL) {
/* Read image. 'read_raw_image' returns NULL on error,
* so we don't have to handle errors here. */
img = read_raw_image(image_path, image_raw_format);
} else if (verify_png_image(image_path)) {
/* Create a pixmap to render on, fill it with the background color */
img = cairo_image_surface_create_from_png(image_path);
/* In case loading failed, we just pretend no -i was specified. */
@ -1079,7 +1201,9 @@ int main(int argc, char *argv[]) {
img = NULL;
}
}
free(image_path);
free(image_raw_format);
/* Pixmap on which the image is rendered to (if any) */
xcb_pixmap_t bg_pixmap = draw_image(last_resolution);