Mercurial > dwindows

changeset 966:d90222530bb9

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Added code to detect the actual color depth of loaded bitmap files on Windows. It seems that any LoadImage() loaded bitmaps are converted to the native screen depth... So using the internal functions to check the depth is useless.
author bsmith@81767d24-ef19-dc11-ae90-00e081727c95
date Tue, 03 May 2011 01:43:51 +0000
parents 2b1b9b995748
children c8490b0d8577
files win/dw.c
diffstat 1 files changed, 52 insertions(+), 19 deletions(-) [+]
line wrap: on
line diff
--- a/win/dw.c	Mon May 02 17:51:35 2011 +0000
+++ b/win/dw.c	Tue May 03 01:43:51 2011 +0000
@@ -8806,15 +8806,58 @@
 
    ReleaseDC(handle, hdc);
 
-#if 0
-   /* force a CONFIGURE event on the underlying renderbox */
-   dw_window_get_pos_size( handle, NULL, NULL, &cx, &cy );
-   SendMessage( handle, WM_SIZE, 0, MAKELPARAM(cx, cy) );
-#endif
-
    return pixmap;
 }
 
+/* Read the file bitmap header ourselves...
+ * apparently we can't check the depth once loaded...
+ * since it seems to normalize it to our screen depth.
+ */
+unsigned long _read_bitmap_header(char *file)
+{
+    BITMAPFILEHEADER header;
+    BITMAPINFO *info;
+    FILE *fp;
+    int infosize;
+    int depth = 0;
+
+    /* Try opening the file; use "rb" mode to read this *binary* file. */
+    if((fp = fopen(file, "rb")) == NULL)
+        return 0;
+
+    /* Read the file header and any following bitmap information... */
+    if(fread(&header, sizeof(BITMAPFILEHEADER), 1, fp) < 1)
+    {
+        /* Couldn't read the file header */
+	    fclose(fp);
+        return 0;
+    }
+
+    if(header.bfType != 'MB')	/* Check for BM reversed... */
+    {
+        /* Not a bitmap file */
+        fclose(fp);
+        return 0;
+    }
+
+    infosize = header.bfOffBits - sizeof(BITMAPFILEHEADER);
+    if((info = (BITMAPINFO *)calloc(infosize, 1)) == NULL)
+    {
+        /* Couldn't allocate memory for bitmap info */
+        fclose(fp);
+        return 0;
+    }
+
+    if(fread(info, 1, infosize, fp) == infosize)
+    {
+        /* Read the bitmap header */
+        depth = info->bmiHeader.biBitCount;
+    }
+    free(info);
+    fclose(fp);
+    return depth;
+}
+
 /*
  * Creates a pixmap from a file.
  * Parameters:
@@ -8832,6 +8875,7 @@
    HDC hdc;
    ULONG cx, cy;
    char *file = malloc(strlen(filename) + 5);
+   BITMAPINFO *info;
 
    if (!file || !(pixmap = calloc(1,sizeof(struct _hpixmap))))
    {
@@ -8859,6 +8903,7 @@
 
    pixmap->handle = handle;
    pixmap->hbm = (HBITMAP)LoadImage(NULL, file, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
+   pixmap->depth = _read_bitmap_header(file);
 
    if ( !pixmap->hbm )
    {
@@ -8871,17 +8916,11 @@
    pixmap->hdc = CreateCompatibleDC( hdc );
    GetObject( pixmap->hbm, sizeof(bm), &bm );
    pixmap->width = bm.bmWidth; pixmap->height = bm.bmHeight;
-   pixmap->depth = bm.bmBitsPixel;
    SelectObject( pixmap->hdc, pixmap->hbm );
    ReleaseDC( handle, hdc );
    free( file );
    pixmap->transcolor = DW_RGB_TRANSPARENT;
 
-#if 0
-   /* force a CONFIGURE event on the underlying renderbox */
-   dw_window_get_pos_size( handle, NULL, NULL, &cx, &cy );
-   SendMessage( handle, WM_SIZE, 0, MAKELPARAM(cx, cy) );
-#endif
    return pixmap;
 }
 
@@ -8922,6 +8961,7 @@
          fwrite( data, 1, len, fp );
          fclose( fp );
          pixmap->hbm = (HBITMAP)LoadImage( NULL, file, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE );
+         pixmap->depth = _read_bitmap_header(file);
       }
       else
       {
@@ -8944,19 +8984,12 @@
    GetObject( pixmap->hbm, sizeof(bm), &bm );
 
    pixmap->width = bm.bmWidth; pixmap->height = bm.bmHeight;
-   pixmap->depth = bm.bmBitsPixel;
 
    SelectObject( pixmap->hdc, pixmap->hbm );
 
    ReleaseDC( handle, hdc );
    pixmap->transcolor = DW_RGB_TRANSPARENT;
 
-#if 0
-   /* force a CONFIGURE event on the underlying renderbox */
-   dw_window_get_pos_size( handle, NULL, NULL, &cx, &cy );
-   SendMessage( handle, WM_SIZE, 0, MAKELPARAM(cx, cy) );
-#endif
-
    return pixmap;
 }