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rockbox/firmware/drivers/lcd-16bit-common.c
Thomas Martitz 312b2a2de7 Document the internal alpha channel format better, and fixes for 32bit alpha bitmaps. 
For images, rows need to be even (this is not true for anti-aliased font files).
Fix stride and size calculation. This makes images that have odd pixel rows display properly and fixes buffer overflows.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30966 a1c6a512-1295-4272-9138-f99709370657
2011-11-11 19:05:11 +00:00

591 lines
18 KiB
C
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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 by Dave Chapman
*
* Rockbox driver for 16-bit colour LCDs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
/* to be #included by lcd-16bit*.c */
#if !defined(ROW_INC) || !defined(COL_INC)
#error ROW_INC or COL_INC not defined
#endif
/* About Rockbox' internal monochrome bitmap format:
*
* A bitmap contains one bit for every pixel that defines if that pixel is
* black (1) or white (0). Bits within a byte are arranged vertically, LSB
* at top.
* The bytes are stored in row-major order, with byte 0 being top left,
* byte 1 2nd from left etc. The first row of bytes defines pixel rows
* 0..7, the second row defines pixel row 8..15 etc.
*
* This is the mono bitmap format used on all other targets so far; the
* pixel packing doesn't really matter on a 8bit+ target. */
/* Draw a partial monochrome bitmap */
void ICODE_ATTR lcd_mono_bitmap_part(const unsigned char *src, int src_x,
int src_y, int stride, int x, int y,
int width, int height)
{
const unsigned char *src_end;
fb_data *dst, *dst_col;
unsigned dmask = 0x100; /* bit 8 == sentinel */
int drmode = current_vp->drawmode;
int row;
/******************** Image in viewport clipping **********************/
/* nothing to draw? */
if ((width <= 0) || (height <= 0) || (x >= current_vp->width) ||
(y >= current_vp->height) || (x + width <= 0) || (y + height <= 0))
return;
if (x < 0)
{
width += x;
src_x -= x;
x = 0;
}
if (y < 0)
{
height += y;
src_y -= y;
y = 0;
}
if (x + width > current_vp->width)
width = current_vp->width - x;
if (y + height > current_vp->height)
height = current_vp->height - y;
/* adjust for viewport */
x += current_vp->x;
y += current_vp->y;
#if defined(HAVE_VIEWPORT_CLIP)
/********************* Viewport on screen clipping ********************/
/* nothing to draw? */
if ((x >= LCD_WIDTH) || (y >= LCD_HEIGHT)
|| (x + width <= 0) || (y + height <= 0))
return;
/* clip image in viewport in screen */
if (x < 0)
{
width += x;
src_x -= x;
x = 0;
}
if (y < 0)
{
height += y;
src_y -= y;
y = 0;
}
if (x + width > LCD_WIDTH)
width = LCD_WIDTH - x;
if (y + height > LCD_HEIGHT)
height = LCD_HEIGHT - y;
#endif
src += stride * (src_y >> 3) + src_x; /* move starting point */
src_y &= 7;
src_end = src + width;
dst_col = LCDADDR(x, y);
if (drmode & DRMODE_INVERSEVID)
{
dmask = 0x1ff; /* bit 8 == sentinel */
drmode &= DRMODE_SOLID; /* mask out inversevid */
}
/* go through each column and update each pixel */
do
{
const unsigned char *src_col = src++;
unsigned data = (*src_col ^ dmask) >> src_y;
int fg, bg;
long bo;
dst = dst_col;
dst_col += COL_INC;
row = height;
#define UPDATE_SRC do { \
data >>= 1; \
if (data == 0x001) { \
src_col += stride; \
data = *src_col ^ dmask; \
} \
} while (0)
switch (drmode)
{
case DRMODE_COMPLEMENT:
do
{
if (data & 0x01)
*dst = ~(*dst);
dst += ROW_INC;
UPDATE_SRC;
}
while (--row);
break;
case DRMODE_BG:
if (lcd_backdrop)
{
bo = lcd_backdrop_offset;
do
{
if (!(data & 0x01))
*dst = *(fb_data *)((long)dst + bo);
dst += ROW_INC;
UPDATE_SRC;
}
while (--row);
}
else
{
bg = current_vp->bg_pattern;
do
{
if (!(data & 0x01))
*dst = bg;
dst += ROW_INC;
UPDATE_SRC;
}
while (--row);
}
break;
case DRMODE_FG:
fg = current_vp->fg_pattern;
do
{
if (data & 0x01)
*dst = fg;
dst += ROW_INC;
UPDATE_SRC;
}
while (--row);
break;
case DRMODE_SOLID:
fg = current_vp->fg_pattern;
if (lcd_backdrop)
{
bo = lcd_backdrop_offset;
do
{
*dst = (data & 0x01) ? fg
: *(fb_data *)((long)dst + bo);
dst += ROW_INC;
UPDATE_SRC;
}
while (--row);
}
else
{
bg = current_vp->bg_pattern;
do
{
*dst = (data & 0x01) ? fg : bg;
dst += ROW_INC;
UPDATE_SRC;
}
while (--row);
}
break;
}
}
while (src < src_end);
}
/* Draw a full monochrome bitmap */
void lcd_mono_bitmap(const unsigned char *src, int x, int y, int width, int height)
{
lcd_mono_bitmap_part(src, 0, 0, width, x, y, width, height);
}
/* About Rockbox' internal alpha channel format (for ALPHA_COLOR_FONT_DEPTH == 2)
*
* For each pixel, 4bit of alpha information is stored in a byte-stream,
* so two pixels are packed into one byte.
* The lower nibble is the first pixel, the upper one the second. The stride is
* horizontal. E.g row0: pixel0: byte0[0:3], pixel1: byte0[4:7], pixel2: byte1[0:3],...
* The format is independant of the internal display orientation, as to
* support the same font files on
* The values go linear from 0 (fully transparent) to 15 (fully opaque).
*
* This might suggest that rows need to have an even number of pixels.
* However this is generally not the case. lcd_alpha_bitmap_part_mix() can deal
* with uneven colums (i.e. two rows can share one byte). And font files do
* exploit this.
* However, this is difficult to do for image files, especially bottom-up bitmaps,
* so lcd_bmp() do expect even rows.
*/
#define ALPHA_COLOR_FONT_DEPTH 2
#define ALPHA_COLOR_LOOKUP_SHIFT (1 << ALPHA_COLOR_FONT_DEPTH)
#define ALPHA_COLOR_LOOKUP_SIZE ((1 << ALPHA_COLOR_LOOKUP_SHIFT) - 1)
#define ALPHA_COLOR_PIXEL_PER_BYTE (8 >> ALPHA_COLOR_FONT_DEPTH)
#define ALPHA_COLOR_PIXEL_PER_WORD (32 >> ALPHA_COLOR_FONT_DEPTH)
#ifdef CPU_ARM
#define BLEND_INIT do {} while (0)
#define BLEND_START(acc, color, alpha) \
asm volatile("mul %0, %1, %2" : "=&r" (acc) : "r" (color), "r" (alpha))
#define BLEND_CONT(acc, color, alpha) \
asm volatile("mla %0, %1, %2, %0" : "+&r" (acc) : "r" (color), "r" (alpha))
#define BLEND_OUT(acc) do {} while (0)
#elif defined(CPU_COLDFIRE)
#define ALPHA_BITMAP_READ_WORDS
#define BLEND_INIT coldfire_set_macsr(EMAC_UNSIGNED)
#define BLEND_START(acc, color, alpha) \
asm volatile("mac.l %0, %1, %%acc0" :: "%d" (color), "d" (alpha))
#define BLEND_CONT BLEND_START
#define BLEND_OUT(acc) asm volatile("movclr.l %%acc0, %0" : "=d" (acc))
#else
#define BLEND_INIT do {} while (0)
#define BLEND_START(acc, color, alpha) ((acc) = (color) * (alpha))
#define BLEND_CONT(acc, color, alpha) ((acc) += (color) * (alpha))
#define BLEND_OUT(acc) do {} while (0)
#endif
/* Blend the given two colors */
static inline unsigned blend_two_colors(unsigned c1, unsigned c2, unsigned a)
{
a += a >> (ALPHA_COLOR_LOOKUP_SHIFT - 1);
#if (LCD_PIXELFORMAT == RGB565SWAPPED)
c1 = swap16(c1);
c2 = swap16(c2);
#endif
unsigned c1l = (c1 | (c1 << 16)) & 0x07e0f81f;
unsigned c2l = (c2 | (c2 << 16)) & 0x07e0f81f;
unsigned p;
BLEND_START(p, c1l, a);
BLEND_CONT(p, c2l, ALPHA_COLOR_LOOKUP_SIZE + 1 - a);
BLEND_OUT(p);
p = (p >> ALPHA_COLOR_LOOKUP_SHIFT) & 0x07e0f81f;
p |= (p >> 16);
#if (LCD_PIXELFORMAT == RGB565SWAPPED)
return swap16(p);
#else
return p;
#endif
}
/* Blend the given color with the value from the alpha_color_lookup table */
static inline unsigned blend_color(unsigned c, unsigned a)
{
return blend_two_colors(c, current_vp->fg_pattern, a);
}
/* Blend an image with an alpha channel
* if image is NULL, drawing will happen according to the drawmode
* src is the alpha channel (4bit per pixel) */
static void ICODE_ATTR lcd_alpha_bitmap_part_mix(const fb_data* image,
const unsigned char *src, int src_x,
int src_y, int x, int y,
int width, int height,
int stride_image, int stride_src)
{
fb_data *dst, *dst_row;
const fb_data *image_row;
unsigned dmask = 0x00000000;
int drmode = current_vp->drawmode;
/* nothing to draw? */
if ((width <= 0) || (height <= 0) || (x >= current_vp->width) ||
(y >= current_vp->height) || (x + width <= 0) || (y + height <= 0))
return;
/* initialize blending */
BLEND_INIT;
/* clipping */
if (x < 0)
{
width += x;
src_x -= x;
x = 0;
}
if (y < 0)
{
height += y;
src_y -= y;
y = 0;
}
if (x + width > current_vp->width)
width = current_vp->width - x;
if (y + height > current_vp->height)
height = current_vp->height - y;
/* adjust for viewport */
x += current_vp->x;
y += current_vp->y;
#if defined(HAVE_VIEWPORT_CLIP)
/********************* Viewport on screen clipping ********************/
/* nothing to draw? */
if ((x >= LCD_WIDTH) || (y >= LCD_HEIGHT)
|| (x + width <= 0) || (y + height <= 0))
return;
/* clip image in viewport in screen */
if (x < 0)
{
width += x;
src_x -= x;
x = 0;
}
if (y < 0)
{
height += y;
src_y -= y;
y = 0;
}
if (x + width > LCD_WIDTH)
width = LCD_WIDTH - x;
if (y + height > LCD_HEIGHT)
height = LCD_HEIGHT - y;
#endif
if (drmode & DRMODE_INVERSEVID)
{
dmask = 0xffffffff;
drmode &= DRMODE_SOLID; /* mask out inversevid */
}
/* sourcing from an image ignore drawmode.
* Set to DRMODE_BG as we use its code path in the switch below */
if (image != NULL)
{
drmode = DRMODE_BG;
}
if (drmode == DRMODE_BG)
{
dmask = ~dmask;
}
dst_row = LCDADDR(x, y);
int col, row = height;
unsigned data, pixels;
unsigned skip_end = (stride_src - width);
unsigned skip_start = src_y * stride_src + src_x;
unsigned skip_start_image = STRIDE_MAIN(src_y * stride_image + src_x,
src_x * stride_image + src_y);
#ifdef ALPHA_BITMAP_READ_WORDS
uint32_t *src_w = (uint32_t *)((uintptr_t)src & ~3);
skip_start += ALPHA_COLOR_PIXEL_PER_BYTE * ((uintptr_t)src & 3);
src_w += skip_start / ALPHA_COLOR_PIXEL_PER_WORD;
data = letoh32(*src_w++) ^ dmask;
pixels = skip_start % ALPHA_COLOR_PIXEL_PER_WORD;
#else
src += skip_start / ALPHA_COLOR_PIXEL_PER_BYTE;
data = *src ^ dmask;
pixels = skip_start % ALPHA_COLOR_PIXEL_PER_BYTE;
#endif
data >>= pixels * ALPHA_COLOR_LOOKUP_SHIFT;
#ifdef ALPHA_BITMAP_READ_WORDS
pixels = 8 - pixels;
#endif
if (image)
image += skip_start_image;
image_row = image;
/* go through the rows and update each pixel */
do
{
col = width;
dst = dst_row;
dst_row += ROW_INC;
if (image_row) {
image = image_row;
image_row += STRIDE_MAIN(stride_image,1);
}
else
image = dst;
#ifdef ALPHA_BITMAP_READ_WORDS
#define UPDATE_SRC_ALPHA do { \
if (--pixels) \
data >>= ALPHA_COLOR_LOOKUP_SHIFT; \
else \
{ \
data = letoh32(*src_w++) ^ dmask; \
pixels = ALPHA_COLOR_PIXEL_PER_WORD; \
} \
} while (0)
#elif ALPHA_COLOR_PIXEL_PER_BYTE == 2
#define UPDATE_SRC_ALPHA do { \
if (pixels ^= 1) \
data >>= ALPHA_COLOR_LOOKUP_SHIFT; \
else \
data = *(++src) ^ dmask; \
} while (0)
#else
#define UPDATE_SRC_ALPHA do { \
if (pixels = (++pixels % ALPHA_COLOR_PIXEL_PER_BYTE)) \
data >>= ALPHA_COLOR_LOOKUP_SHIFT; \
else \
data = *(++src) ^ dmask; \
} while (0)
#endif
/* we don't want to have this in our inner
* loop and the codesize increase is minimal */
switch (drmode)
{
case DRMODE_COMPLEMENT:
do
{
*dst = blend_two_colors(*dst, ~(*dst),
data & ALPHA_COLOR_LOOKUP_SIZE );
dst += COL_INC;
UPDATE_SRC_ALPHA;
}
while (--col);
break;
case DRMODE_BG:
if(lcd_backdrop)
{
uintptr_t bo = lcd_backdrop_offset;
do
{
*dst = blend_two_colors(*(fb_data *)((uintptr_t)dst + bo),
*image, data & ALPHA_COLOR_LOOKUP_SIZE );
dst += COL_INC;
image += STRIDE_MAIN(1, stride_image);
UPDATE_SRC_ALPHA;
}
while (--col);
}
else
{
do
{
*dst = blend_two_colors(current_vp->bg_pattern,
*image, data & ALPHA_COLOR_LOOKUP_SIZE );
dst += COL_INC;
image += STRIDE_MAIN(1, stride_image);
UPDATE_SRC_ALPHA;
}
while (--col);
}
break;
case DRMODE_FG:
do
{
*dst = blend_color(*dst, data & ALPHA_COLOR_LOOKUP_SIZE );
dst += COL_INC;
UPDATE_SRC_ALPHA;
}
while (--col);
break;
case DRMODE_SOLID:
if(lcd_backdrop)
{
uintptr_t bo = lcd_backdrop_offset;
do
{
*dst = blend_color(*(fb_data *)((uintptr_t)dst + bo),
data & ALPHA_COLOR_LOOKUP_SIZE );
dst += COL_INC;
UPDATE_SRC_ALPHA;
}
while (--col);
}
else
{
do
{
*dst = blend_color(current_vp->bg_pattern,
data & ALPHA_COLOR_LOOKUP_SIZE );
dst += COL_INC;
UPDATE_SRC_ALPHA;
}
while (--col);
}
break;
}
#ifdef ALPHA_BITMAP_READ_WORDS
if (skip_end < pixels)
{
pixels -= skip_end;
data >>= skip_end * ALPHA_COLOR_LOOKUP_SHIFT;
} else {
pixels = skip_end - pixels;
src_w += pixels / ALPHA_COLOR_PIXEL_PER_WORD;
pixels %= ALPHA_COLOR_PIXEL_PER_WORD;
data = letoh32(*src_w++) ^ dmask;
data >>= pixels * ALPHA_COLOR_LOOKUP_SHIFT;
pixels = 8 - pixels;
}
#else
if (skip_end)
{
pixels += skip_end;
if (pixels >= ALPHA_COLOR_PIXEL_PER_BYTE)
{
src += pixels / ALPHA_COLOR_PIXEL_PER_BYTE;
pixels %= ALPHA_COLOR_PIXEL_PER_BYTE;
data = *src ^ dmask;
data >>= pixels * ALPHA_COLOR_LOOKUP_SHIFT;
} else
data >>= skip_end * ALPHA_COLOR_LOOKUP_SHIFT;
}
#endif
} while (--row);
}
/* draw alpha bitmap for anti-alias font */
void ICODE_ATTR lcd_alpha_bitmap_part(const unsigned char *src, int src_x,
int src_y, int stride, int x, int y,
int width, int height)
{
lcd_alpha_bitmap_part_mix(NULL, src, src_x, src_y, x, y, width, height, 0, stride);
}
/* Draw a partial bitmap (mono or native) including alpha channel */
void ICODE_ATTR lcd_bmp_part(const struct bitmap* bm, int src_x, int src_y,
int x, int y, int width, int height)
{
int bitmap_stride = STRIDE_MAIN(bm->width, bm->height);
if (bm->format == FORMAT_MONO)
lcd_mono_bitmap_part(bm->data, src_x, src_y, bitmap_stride, x, y, width, height);
else if (bm->alpha_offset > 0)
lcd_alpha_bitmap_part_mix((fb_data*)bm->data, bm->data+bm->alpha_offset,
src_x, src_y, x, y, width, height,
bitmap_stride, ALIGN_UP(bm->width, 2));
else
lcd_bitmap_transparent_part((fb_data*)bm->data,
src_x, src_y, bitmap_stride, x, y, width, height);
}
/* Draw a native bitmap with alpha channel */
void ICODE_ATTR lcd_bmp(const struct bitmap *bmp, int x, int y)
{
lcd_bmp_part(bmp, 0, 0, x, y, bmp->width, bmp->height);
}
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