vesa: for jpg or png images, tile the image across the screen

If we specify a smaller image than the screen size, tile it across the
screen rather than leaving a big black box.  This may have to be made
configurable.

Also note that Syslinux currently does not handle the case of an image
bleeding off the end of the screen.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/com32/lib/sys/vesa/background.c b/com32/lib/sys/vesa/background.c
index 2e57384..8d73239 100644 (file)
--- a/com32/lib/sys/vesa/background.c
+++ b/com32/lib/sys/vesa/background.c
@@ -75,26 +75,54 @@ static void draw_background(void)
     __vesacon_redraw_text();
 }
 
+/*
+ * Tile an image in the UL corner across the entire screen
+ */
+static void tile_image(int width, int height)
+{
+    int xsize = __vesa_info.mi.h_res;
+    int ysize = __vesa_info.mi.v_res;
+    int x, y, yr;
+    int xl, yl;
+    uint32_t *sp, *dp, *drp, *dtp;
+
+    drp = __vesacon_background;
+    for (y = 0 ; y < ysize ; y += height) {
+       yl = min(height, ysize-y);
+       dtp = drp;
+       for (x = 0 ; x < xsize ; x += width) {
+           xl = min(width, xsize-x);
+           if (x || y) {
+               sp = __vesacon_background;
+               dp = dtp;
+               for (yr = 0 ; yr < yl ; yr++) {
+                   memcpy(dp, sp, xl*sizeof(uint32_t));
+                   dp += xsize;
+                   sp += xsize;
+               }
+           }
+           dtp += xl;
+       }
+       drp += xsize*height;
+    }
+}
+
 static int read_png_file(FILE * fp)
 {
     png_structp png_ptr = NULL;
     png_infop info_ptr = NULL;
-    png_infop end_ptr = NULL;
 #if 0
     png_color_16p image_background;
     static const png_color_16 my_background = { 0, 0, 0, 0, 0 };
 #endif
     png_bytep row_pointers[__vesa_info.mi.v_res], rp;
-    int passes;
     int i;
     int rv = -1;
 
     png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-
     info_ptr = png_create_info_struct(png_ptr);
-    end_ptr = png_create_info_struct(png_ptr);
 
-    if (!png_ptr || !info_ptr || !end_ptr || setjmp(png_jmpbuf(png_ptr)))
+    if (!png_ptr || !info_ptr || setjmp(png_jmpbuf(png_ptr)))
        goto err;
 
     png_init_io(png_ptr, fp);
@@ -146,16 +174,15 @@ static int read_png_file(FILE * fp)
        rp += __vesa_info.mi.h_res << 2;
     }
 
-    passes = png_set_interlace_handling(png_ptr);
+    png_read_image(png_ptr, row_pointers);
 
-    for (i = 0; i < passes; i++)
-       png_read_rows(png_ptr, row_pointers, NULL, info_ptr->height);
+    tile_image(info_ptr->width, info_ptr->height);
 
     rv = 0;
 
 err:
     if (png_ptr)
-       png_destroy_read_struct(&png_ptr, (png_infopp) NULL, (png_infopp) NULL);
+       png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp) NULL);
     return rv;
 }
 
@@ -198,6 +225,7 @@ static int read_jpeg_file(FILE * fp, uint8_t * header, int len)
     tinyjpeg_set_bytes_per_row(jdec, bytes_per_row, 1);
 
     tinyjpeg_decode(jdec, TINYJPEG_FMT_BGRA32);
+    tile_image(width, height);
 
     rv = 0;