picoproj: add a note about image dimensions and native resolution

Also print a warning when the user supplies a big image, picoproj does
not perform any rescale so the device may just display a wrong picture
or even hang.

diff --git a/doc/man/picoproj.1.txt b/doc/man/picoproj.1.txt
index c60fe16..ce56f0e 100644 (file)
--- a/doc/man/picoproj.1.txt
+++ b/doc/man/picoproj.1.txt
@@ -15,7 +15,9 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-picoproj(1) is a minimal example to show how to use libam7xxx to display a static image.
+picoproj(1) is a minimal example to show how to use libam7xxx to display
+a static image; it will not perform any image rescaling or conversion, images
+larger than the device native resolution can be wrongly displayed.
 
 
 OPTIONS

diff --git a/examples/picoproj.c b/examples/picoproj.c
index 105169c..2c1b257 100644 (file)
--- a/examples/picoproj.c
+++ b/examples/picoproj.c
@@ -209,6 +209,10 @@ int main(int argc, char *argv[])
                goto cleanup;
        }
 
+       if ((unsigned int)width > device_info.native_width ||
+           (unsigned int)height > device_info.native_height)
+               fprintf(stderr, "WARNING: image not fitting the native resolution, it may be displayed wrongly!\n");
+
        ret = am7xxx_send_image(dev, format, width, height, image, size);
        if (ret < 0) {
                perror("am7xxx_send_image");