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authorKarl Kurbjun <kkurbjun@gmail.com>2009-09-04 01:28:50 +0000
committerKarl Kurbjun <kkurbjun@gmail.com>2009-09-04 01:28:50 +0000
commit067172ae549aa5594769bba21add474b6d6d6e8f (patch)
tree9461f784a1382df4bfe43c7a4d6a75f284b55d9a /firmware
parent25123570c76f2055d3ae05d79741038c0e23c536 (diff)
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Explain the stride and fix the player.
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22616 a1c6a512-1295-4272-9138-f99709370657
Diffstat (limited to 'firmware')
-rw-r--r--firmware/export/lcd.h81
1 files changed, 62 insertions, 19 deletions
diff --git a/firmware/export/lcd.h b/firmware/export/lcd.h
index 3f3d8f875f..c301c4c0d1 100644
--- a/firmware/export/lcd.h
+++ b/firmware/export/lcd.h
@@ -46,6 +46,68 @@ struct viewport {
#endif
};
+/* Frame buffer stride
+ *
+ * Stride describes the amount that you need to increment to get to the next
+ * line. For screens that have the pixels in contiguous horizontal strips
+ * stride should be equal to the image width.
+ *
+ * For example, if the screen pixels are layed out as follows:
+ *
+ * width0 width1 width2 widthX-1
+ * ------ ------ ------ ------------------ --------
+ * height0 | pixel0 pixel1 pixel2 ----------------> pixelX-1
+ * height1 | pixelX
+ *
+ * then you need to add X pixels to get to the next line. (the next line
+ * in this case is height1).
+ *
+ * Similarly, if the screens is has the pixels in contiguous vertical strips
+ * the stride would be equal to the image height.
+ *
+ * For example if the screen pixels are layed out as follows:
+ *
+ * width0 width1
+ * ------ ------
+ * height0 | pixel0 pixelY
+ * height1 | pixel1
+ * height2 | pixel2
+ * | | |
+ * \|/ | \|/
+ * heightY-1 | pixelY-1
+ *
+ * then you would need to add Y pixels to get to the next line (the next
+ * line in this case is from width0 to width1).
+ *
+ * The remote might have a different stride than the main screen so the screen
+ * number needs to be passed to the STRIDE macro so that the appropriate height
+ * or width can be passed to the lcd_bitmap, or lcd_remote_bitmap calls.
+ *
+ * STRIDE_REMOTE and STRIDE_MAIN should never used when it is not clear whether
+ * lcd_remote_bitmap calls or lcd_bitmap calls are being made (for example the
+ * screens api).
+ *
+ * Screen should always use the screen_type enum that is at the top of this
+ * header.
+ */
+enum screen_type {
+ SCREEN_MAIN
+#ifdef HAVE_REMOTE_LCD
+ ,SCREEN_REMOTE
+#endif
+};
+
+#if defined(LCD_STRIDEFORMAT) && LCD_STRIDEFORMAT == VERTICAL_STRIDE
+#define STRIDE_MAIN(w, h) (h)
+#else
+#define STRIDE_MAIN(w, h) (w)
+#endif
+
+#define STRIDE_REMOTE(w, h) (w)
+
+#define STRIDE(screen, w, h) (screen==SCREEN_MAIN?STRIDE_MAIN((w), \
+ (h)):STRIDE_REMOTE((w),(h)))
+
#define STYLE_DEFAULT 0x00000000
#define STYLE_COLORED 0x10000000
#define STYLE_INVERT 0x20000000
@@ -306,25 +368,6 @@ static inline unsigned lcd_color_to_native(unsigned color)
#endif /* HAVE_LCD_COLOR */
-enum screen_type {
- SCREEN_MAIN
-#ifdef HAVE_REMOTE_LCD
- ,SCREEN_REMOTE
-#endif
-};
-
-/* Frame buffer stride */
-#define STRIDE_REMOTE(w, h) (w)
-
-#if defined(LCD_STRIDEFORMAT) && LCD_STRIDEFORMAT == VERTICAL_STRIDE
-#define STRIDE_MAIN(w, h) (h)
-#else
-#define STRIDE_MAIN(w, h) (w)
-#endif
-
-#define STRIDE(screen, w, h) (screen==SCREEN_MAIN?STRIDE_MAIN((w), \
- (h)):STRIDE_REMOTE((w),(h)))
-
/* Frame buffer dimensions */
#if LCD_DEPTH == 1
#if LCD_PIXELFORMAT == HORIZONTAL_PACKING