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fbink.c
12801 lines (11843 loc) · 456 KB
/
fbink.c
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/*
FBInk: FrameBuffer eInker, a library to print text & images to an eInk Linux framebuffer
Copyright (C) 2018-2024 NiLuJe <ninuje@gmail.com>
SPDX-License-Identifier: GPL-3.0-or-later
----
Some (the 8/16/24/32bpp put_pixel_* variants) Linux framebuffer writing routines based on: fbtestfnt.c & fbtest6.c, from
https://raspberrycompote.blogspot.com/2014/04/low-level-graphics-on-raspberry-pi-text.html &
https://raspberrycompote.blogspot.com/2013/03/low-level-graphics-on-raspberry-pi-part_8.html
Original works by J-P Rosti (a.k.a -rst- and 'Raspberry Compote'),
Licensed under the Creative Commons Attribution 3.0 Unported License
(http://creativecommons.org/licenses/by/3.0/deed.en_US)
Ordered dithering routine (dither_o8x8) completely based on ImageMagick's implementation,
(OrderedDitherImage @ https://github.com/ImageMagick/ImageMagick/blob/master/MagickCore/threshold.c),
Copyright 1999-2019 ImageMagick Studio LLC,
Licensed under the ImageMagick License,
(https://imagemagick.org/script/license.php)
----
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 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
#include "fbink.h"
#include "fbink_internal.h"
#ifdef FBINK_WITH_IMAGE
# define STB_IMAGE_IMPLEMENTATION
// Make it private, we don't need it anywhere else
# define STB_IMAGE_STATIC
// Disable HDR, as well as the linear light API, to avoid pulling in libm
# define STBI_NO_HDR
# define STBI_NO_LINEAR
// We want SIMD for JPEG decoding (... if we can actually use it)!
// It's not the end of the world if we can't, the speed gains are minimal (~5%).
# ifdef __ARM_NEON
# define STBI_NEON
# endif
// We don't care about those formats (PhotoShop, AutoDesk)
# define STBI_NO_PSD
# define STBI_NO_PIC
// We can't use stbi_failure_reason as it's not thread-safe, so ditch the strings
# define STBI_NO_FAILURE_STRINGS
// Prevent attempting to decode ginormous images
# define STBI_MAX_DIMENSIONS (1 << 13)
// Disable a bunch of very verbose but mostly harmless warnings
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wunknown-pragmas"
# pragma clang diagnostic ignored "-Wunknown-warning-option"
# pragma GCC diagnostic ignored "-Wcast-qual"
# pragma GCC diagnostic ignored "-Wcast-align"
# pragma GCC diagnostic ignored "-Wconversion"
# pragma GCC diagnostic ignored "-Wsign-conversion"
# pragma GCC diagnostic ignored "-Wduplicated-branches"
# pragma GCC diagnostic ignored "-Wunused-function"
# pragma GCC diagnostic ignored "-Wsign-compare"
# pragma GCC diagnostic ignored "-Wunused-but-set-variable"
# pragma GCC diagnostic ignored "-Wsuggest-attribute=pure"
# include "stb/stb_image.h"
# pragma GCC diagnostic pop
#endif
#ifdef FBINK_WITH_OPENTYPE
# define STB_TRUETYPE_IMPLEMENTATION
// Make it private, we don't need it anywhere else
# define STBTT_STATIC
// stb_truetype is.... noisy
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wunknown-pragmas"
# pragma clang diagnostic ignored "-Wunknown-warning-option"
# pragma GCC diagnostic ignored "-Wcast-qual"
# pragma GCC diagnostic ignored "-Wconversion"
# pragma GCC diagnostic ignored "-Wsign-conversion"
# pragma GCC diagnostic ignored "-Wunused-function"
# pragma GCC diagnostic ignored "-Wsuggest-attribute=pure"
# include "stb/stb_truetype.h"
# pragma GCC diagnostic pop
#endif
// Return the library version as devised at library compile-time
const char*
fbink_version(void)
{
return FBINK_VERSION;
}
// Return the target platform of the current library build
FBINK_TARGET_T
fbink_target(void)
{
#if defined(FBINK_FOR_LINUX)
return FBINK_TARGET_LINUX;
#elif defined(FBINK_FOR_KOBO)
return FBINK_TARGET_KOBO;
#elif defined(FBINK_FOR_KINDLE)
return FBINK_TARGET_KINDLE;
#elif defined(FBINK_FOR_LEGACY)
return FBINK_TARGET_KINDLE_LEGACY;
#elif defined(FBINK_FOR_CERVANTES)
return FBINK_TARGET_CERVANTES;
#elif defined(FBINK_FOR_REMARKABLE)
return FBINK_TARGET_REMARKABLE;
#elif defined(FBINK_FOR_POCKETBOOK)
return FBINK_TARGET_POCKETBOOK;
#else
// Unreachable
return FBINK_TARGET_MAX;
#endif
}
// Return the feature set of the current library build
uint32_t
fbink_features(void)
{
#ifndef FBINK_MINIMAL
uint32_t features = FBINK_FEATURE_FULL;
#else
uint32_t features = FBINK_FEATURE_MINIMAL;
# ifdef FBINK_WITH_DRAW
features |= FBINK_FEATURE_DRAW;
# endif
# ifdef FBINK_WITH_BITMAP
features |= FBINK_FEATURE_BITMAP;
# endif
# ifdef FBINK_WITH_FONTS
features |= FBINK_FEATURE_FONTS;
# endif
# ifdef FBINK_WITH_UNIFONT
features |= FBINK_FEATURE_UNIFONT;
# endif
# ifdef FBINK_WITH_OPENTYPE
features |= FBINK_FEATURE_OPENTYPE;
# endif
# ifdef FBINK_WITH_IMAGE
features |= FBINK_FEATURE_IMAGE;
# endif
# ifdef FBINK_WITH_BUTTON_SCAN
features |= FBINK_FEATURE_BUTTON_SCAN;
# endif
# ifdef FBINK_WITH_INPUT
features |= FBINK_FEATURE_INPUT;
# endif
#endif // !FBINK_MINIMAL
return features;
}
#ifdef FBINK_WITH_DRAW
// #RGB -> BGR565
static inline __attribute__((const, always_inline, hot)) uint16_t
pack_bgr565(uint8_t r, uint8_t g, uint8_t b)
{
// ((r / 8) * 2048) + ((g / 4) * 32) + (b / 8);
return (uint16_t) (((r >> 3U) << 11U) | ((g >> 2U) << 5U) | (b >> 3U));
}
// #RGB -> RGB565
static inline __attribute__((const, always_inline, hot)) uint16_t
pack_rgb565(uint8_t r, uint8_t g, uint8_t b)
{
// ((b / 8) * 2048) + ((g / 4) * 32) + (r / 8);
return (uint16_t) (((b >> 3U) << 11U) | ((g >> 2U) << 5U) | (r >> 3U));
}
# ifdef FBINK_WITH_DRAW
// Pack an FBInkPixel accordingly for the target pixel format
static __attribute__((pure)) FBInkPixel
pack_pixel_from_rgba(uint8_t r, uint8_t g, uint8_t b, uint8_t a)
{
FBInkPixel px;
switch (deviceQuirks.pixelFormat) {
case FBINK_PXFMT_Y4:
case FBINK_PXFMT_Y8:
// NOTE: We inline stbi__compute_y to avoid needing to depend on FBINK_WITH_IMAGE
px.gray8 = (uint8_t) (((r * 77U) + (g * 150U) + (29U * b)) >> 8U);
break;
case FBINK_PXFMT_BGR565:
px.rgb565 = pack_bgr565(r, g, b);
break;
case FBINK_PXFMT_RGB565:
px.rgb565 = pack_rgb565(r, g, b);
break;
case FBINK_PXFMT_BGR24:
case FBINK_PXFMT_BGRA:
case FBINK_PXFMT_BGR32:
default:
px.bgra.color.b = b;
px.bgra.color.g = g;
px.bgra.color.r = r;
px.bgra.color.a = a;
break;
case FBINK_PXFMT_RGB24:
case FBINK_PXFMT_RGBA:
case FBINK_PXFMT_RGB32:
px.rgba.color.r = r;
px.rgba.color.g = g;
px.rgba.color.b = b;
px.rgba.color.a = a;
break;
}
return px;
}
static __attribute__((pure)) FBInkPixel
pack_pixel_from_y8(uint8_t v)
{
FBInkPixel px;
switch (deviceQuirks.pixelFormat) {
case FBINK_PXFMT_Y4:
case FBINK_PXFMT_Y8:
px.gray8 = v;
break;
case FBINK_PXFMT_BGR565:
case FBINK_PXFMT_RGB565:
px.rgb565 = pack_rgb565(v, v, v);
break;
case FBINK_PXFMT_BGR24:
case FBINK_PXFMT_BGRA:
case FBINK_PXFMT_BGR32:
case FBINK_PXFMT_RGB24:
case FBINK_PXFMT_RGBA:
case FBINK_PXFMT_RGB32:
default:
px.bgra.color.b = v;
px.bgra.color.g = v;
px.bgra.color.r = v;
px.bgra.color.a = 0xFFu;
break;
}
return px;
}
# endif // FBINK_WITH_DRAW
// Helper functions to 'plot' a specific pixel in a given color to the framebuffer
static inline __attribute__((always_inline, hot)) void
put_pixel_Gray4(const FBInkCoordinates* restrict coords, const FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
// note: x / 2 as every byte holds 2 pixels
const size_t pix_offset = (coords->x >> 1U) + (coords->y * fInfo.line_length);
// NOTE: Squash 8bpp to 4bpp:
// (v >> 4)
// or: v * 16 / 256
// First, we'll need the current full byte to make sure we never clobber a nibble...
const uint8_t b = *((unsigned char*) (fbPtr + pix_offset));
// We can't address nibbles directly, so this takes some shenanigans...
if ((coords->x & 0x01u) == 0U) {
// Even pixel: high nibble
// ORed to avoid clobbering our odd pixel
*((unsigned char*) (fbPtr + pix_offset)) = (unsigned char) ((b & 0x0Fu) | (px->gray8 & 0xF0u));
// Squash to 4bpp, and write to the top/left nibble
// or: ((v >> 4) << 4)
} else {
// Odd pixel: low nibble
// ORed to avoid clobbering our even pixel
*((unsigned char*) (fbPtr + pix_offset)) = (unsigned char) ((b & 0xF0u) | (px->gray8 >> 4U));
}
}
static inline __attribute__((always_inline, hot)) void
put_pixel_Gray8(const FBInkCoordinates* restrict coords, const FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
const size_t pix_offset = coords->x + (coords->y * fInfo.line_length);
// now this is about the same as 'fbp[pix_offset] = value'
*((unsigned char*) (fbPtr + pix_offset)) = px->gray8;
}
static inline __attribute__((always_inline)) void
put_pixel_BGR24(const FBInkCoordinates* restrict coords, const FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
// note: x * 3 as every pixel is 3 consecutive bytes
const size_t pix_offset = (coords->x * 3U) + (coords->y * fInfo.line_length);
// now this is about the same as 'fbp[pix_offset] = value'
// NOTE: Technically legitimate warning. In practice, we always pass RGB32 pixels in 24bpp codepaths.
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wunknown-pragmas"
# pragma clang diagnostic ignored "-Wunknown-warning-option"
# pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
*((unsigned char*) (fbPtr + pix_offset)) = px->bgra.color.b;
*((unsigned char*) (fbPtr + pix_offset + 1U)) = px->bgra.color.g;
*((unsigned char*) (fbPtr + pix_offset + 2U)) = px->bgra.color.r;
# pragma GCC diagnostic pop
}
static inline __attribute__((always_inline)) void
put_pixel_RGB24(const FBInkCoordinates* restrict coords, const FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
// note: x * 3 as every pixel is 3 consecutive bytes
const size_t pix_offset = (coords->x * 3U) + (coords->y * fInfo.line_length);
// now this is about the same as 'fbp[pix_offset] = value'
// NOTE: Technically legitimate warning. In practice, we always pass RGB32 pixels in 24bpp codepaths.
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wunknown-pragmas"
# pragma clang diagnostic ignored "-Wunknown-warning-option"
# pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
*((unsigned char*) (fbPtr + pix_offset)) = px->rgba.color.r;
*((unsigned char*) (fbPtr + pix_offset + 1U)) = px->rgba.color.g;
*((unsigned char*) (fbPtr + pix_offset + 2U)) = px->rgba.color.b;
# pragma GCC diagnostic pop
}
static inline __attribute__((always_inline, hot)) void
put_pixel_RGB32(const FBInkCoordinates* restrict coords, const FBInkPixel* restrict px)
{
// calculate the scanline's byte offset inside the buffer
const size_t scanline_offset = (size_t) coords->y * fInfo.line_length;
// write the four bytes at once
// NOTE: We rely on pointer arithmetic rules to handle the pixel offset inside the scanline,
// i.e., if we add x *after* the cast, that's an addition of x uint32_t elements, meaning x times 4 bytes,
// which is exactly what we want ;).
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wcast-align"
*((uint32_t*) (fbPtr + scanline_offset) + coords->x) = px->p;
# pragma GCC diagnostic pop
}
static inline __attribute__((always_inline, hot)) void
put_pixel_RGB565(const FBInkCoordinates* restrict coords, const FBInkPixel* restrict px)
{
// calculate the scanline's byte offset inside the buffer
const size_t scanline_offset = (size_t) coords->y * fInfo.line_length;
// write the two bytes at once, much to GCC's dismay...
// NOTE: Input pixel *has* to be properly packed to BGR565/RGB565 first (via pack_bgr565/pack_rgb565, c.f., put_pixel)!
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wcast-align"
*((uint16_t*) (fbPtr + scanline_offset) + coords->x) = px->rgb565;
# pragma GCC diagnostic pop
}
#endif // FBINK_WITH_DRAW
#if defined(FBINK_FOR_KOBO) || defined(FBINK_FOR_CERVANTES) || defined(FBINK_FOR_POCKETBOOK)
// Handle rotation quirks...
static void
rotate_coordinates_pickel(FBInkCoordinates* restrict coords)
{
// Rotate the coordinates to account for pickel's rotation...
const unsigned short int rx = coords->y;
const unsigned short int ry = (unsigned short int) (screenWidth - coords->x - 1);
// NOTE: This codepath is not production ready, it was just an experiment to wrap my head around framebuffer rotation...
// In particular, only CW has been actually confirmed to behave properly (to handle the isNTX16bLandscape quirk),
// and region rotation is NOT handled properly/at all.
// TL;DR: This is for documentation purposes only, never build w/ MATHS defined ;).
# ifdef FBINK_WITH_MATHS_ROTA
uint8_t rotation = FB_ROTATE_CW;
// i.e., θ (c.f., https://en.wikipedia.org/wiki/Cartesian_coordinate_system#Rotation)
double rangle = ((rotation * 90) * M_PI / 180.0);
double fxp = coords->x * cos(rangle) - coords->y * sin(rangle);
double fyp = coords->x * sin(rangle) + coords->y * cos(rangle);
LOG("(fxp, fyp) -> (%f, %f)", fxp, fyp);
unsigned short int xp;
unsigned short int yp;
switch (rotation) {
case FB_ROTATE_CW:
xp = (unsigned short int) lround(-fxp);
yp = (unsigned short int) lround(vInfo.yres - 1 - fyp);
break;
case FB_ROTATE_UD:
// NOTE: IIRC, this pretty much ends up with (x', y') being equal to (y, x).
xp = (unsigned short int) lround(-fyp);
yp = (unsigned short int) lround(-fxp);
break;
case FB_ROTATE_CCW:
xp = (unsigned short int) lround(vInfo.xres - 1 - fxp);
yp = (unsigned short int) lround(-fyp);
break;
default:
xp = (unsigned short int) lround(fxp);
yp = (unsigned short int) lround(fyp);
break;
}
LOG("(x, y) -> (%hu, %hu) vs. (rx, ry) -> (%hu, %hu) vs. (x', y') -> (%hu, %hu)",
coords->x,
coords->y,
rx,
ry,
xp,
yp);
coords->x = xp;
coords->y = yp;
# else
coords->x = rx;
coords->y = ry;
# endif
}
#endif // FBINK_FOR_KOBO || FBINK_FOR_CERVANTES || FBINK_FOR_POCKETBOOK
#if defined(FBINK_FOR_KOBO) || defined(FBINK_FOR_CERVANTES)
static void
rotate_coordinates_boot(FBInkCoordinates* restrict coords)
{
// Rotate the coordinates to account for the native boot rotation...
// NOTE: See the note is fbink_init, this is based on a replicated boot modeset,
// which apparently doesn't exactly match the *real* boot modeset... -_-".
const unsigned short int rx = (unsigned short int) (screenHeight - coords->y - 1);
const unsigned short int ry = coords->x;
coords->x = rx;
coords->y = ry;
}
# ifdef FBINK_WITH_BUTTON_SCAN
// NOTE: Do *not* trust this to do the right thing, see utils/finger_trace.c instead!
// This is basically left as-is for archeological purposes only,
// the only caller is in button_scan, which was kind of a crazy experiment to begin with ;).
static void
rotate_touch_coordinates(FBInkCoordinates* restrict coords)
{
unsigned short int rx = coords->x;
unsigned short int ry = coords->y;
uint32_t rotation = vInfo.rotate;
// NOTE: Try to take into account the various rotation quirks, depending on the device...
// c.f., mxc_epdc_fb_check_var @ drivers/video/mxc/mxc_epdc_fb.c OR drivers/video/fbdev/mxc/mxc_epdc_v2_fb.c
if (deviceQuirks.ntxRotaQuirk == NTX_ROTA_ODD_INVERTED) {
// On the Forma, only Portrait orientations are inverted...
// When I say Portrait/Landscape, that's how the device *looks*, which doesn't match the FB_ROTATE_* constants...
// i.e., in Nickel, *visually*, UR is 3, CW is 2, UD is 1, CCW is 0,
// and when sending ioctls, UR returns 0 (match), CW returns 3 (^= 2), UD returns 2 (match), CCW returns 1 (^= 2).
if (rotation & 0x01u) {
// Rotation constant is odd (i.e., CW or CCW), invert it.
rotation ^= 2U;
}
// NOTE: Plato goes with a simple rotation = (4 - rotation) % 4; which does the exact same thing,
// I just have a harder time wrapping my head around it ;).
// Plus, I'm inclined to believe a simple branch would be faster than a modulo.
} else if (deviceQuirks.ntxRotaQuirk == NTX_ROTA_ALL_INVERTED) {
// On *some* devices with a 6.8" panel, *every* orientation is inverted...
rotation ^= 2U;
} else if (deviceQuirks.ntxRotaQuirk == NTX_ROTA_SANE) {
// NOTE: This is for the Libra, but I don't have access to that device to double-check...
// And I probably never will, see the deprecation comment above this function ;).
// The reasoning being to try to match the Forma's behavior:
// UR -> 3 ^ 2 -> CW / CW -> 2 -> UD / UD -> 1 ^ 2 -> CCW / CCW -> 0 -> UR
// The format being: *effective* orientation (i.e., user-facing) -> actual fb rotate value -> input transform
// Wich means we essentially want:
// UR -> CW / CW -> UD / UD -> CCW / CCW -> UR
// Given the fact that the Libra's panel is finally Portrait, and kept @ UR (boot, pickel & nickel),
// effective orientation & fb rotate value should always match,
// that means we just need to shift by +90°, one CW rotation.
// I suspect this bit of insanity was actually mangled back in for backwards compatibility w/ NTX shenanigans...
rotation = (rotation + 1U) & 3U;
}
// NOTE: Should match *most* Kobo devices...
// c.f., https://patchwork.openembedded.org/patch/149258
// NOTE: See also create_and_get_mt_pdata @ drivers/input/touchscreen/cyttsp5_devtree.c,
// there may be method to this madness...
switch (rotation) {
case FB_ROTATE_UR:
// NOP!
break;
case FB_ROTATE_CW:
rx = coords->y;
ry = (unsigned short int) (screenWidth - coords->x - 1);
break;
case FB_ROTATE_UD:
rx = (unsigned short int) (screenWidth - coords->x - 1);
ry = (unsigned short int) (screenHeight - coords->y - 1);
break;
case FB_ROTATE_CCW:
rx = (unsigned short int) (screenHeight - coords->y - 1);
ry = coords->x;
break;
}
// NOTE: The H2O²r1 (possibly r2 as well), on the other hand, is a special snowflake...
// (It'll need a dedicated deviceQuirks).
// c.f., https://www.mobileread.com/forums/showpost.php?p=3766627&postcount=236
// & https://github.com/baskerville/plato/commit/5181eaf0b48a9e1201b6ea5751c2af108512f74f
// & https://github.com/baskerville/plato/commit/bf7af35eef9c29250d206687738b4888f40ecab1
/*
switch(rotation) {
case FB_ROTATE_UR:
rx = coords->x;
ry = (unsigned short int) (screenHeight - coords->y - 1);
break;
case FB_ROTATE_CW:
rx = (unsigned short int) (screenHeight - coords->y - 1);
ry = (unsigned short int) (screenWidth - coords->x - 1);
break;
case FB_ROTATE_UD:
rx = (unsigned short int) (screenWidth - coords->x - 1);
ry = coords->y;
break;
case FB_ROTATE_CCW:
rx = coords->y;
ry = coords->x;
break;
}
*/
coords->x = rx;
coords->y = ry;
}
# endif // FBINK_WITH_BUTTON_SCAN
#endif // FBINK_FOR_KOBO || FBINK_FOR_CERVANTES
static void
rotate_coordinates_nop(FBInkCoordinates* restrict coords __attribute__((unused)))
{
// NOP!
// May be smarter than one might think on armv7-a,
// (quoting http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.100069_0610_01_en/pge1425898111637.html
// "NOP is not necessarily a time-consuming NOP.
// The processor might remove it from the pipeline before it reaches the execution stage."),
// which might explain why this isn't worse than branching (i.e., what we did before
// https://github.com/NiLuJe/FBInk/commit/75407d4a44d7bfc7705665ad4ec9ecad0d03a368).
}
#ifdef FBINK_WITH_DRAW
// Handle a few sanity checks...
// NOTE: If you can, prefer using the right put_pixel_* function directly.
// While the bounds checking is generally rather cheap,
// (i.e., (*fxpPutPixel) is only marginally faster than put_pixel()),
// the overhead of going through the function pointers is rather large
// (i.e., put_pixel() can be twice as slow as put_pixel_*()).
// On the oldest of our target HW, it's often *slightly* faster than branching or switching, though ;).
// But on modern processors, even on our target HW, branching should eventually take the lead, though,
// and in this case (ha!) appears to behave *noticeably* better than switching...
// Which is why we now branch via an if ladder, as it should offer marginally better performance on newer devices.
static inline __attribute__((always_inline, hot)) void
put_pixel(FBInkCoordinates coords, const FBInkPixel* restrict px, bool is_rgb565)
{
// Handle rotation now, so we can properly validate if the pixel is off-screen or not ;).
// fbink_init() takes care of setting this global pointer to the right function...
// NOTE: In this case, going through the function pointer is *noticeably* faster than branching...
(*fxpRotateCoords)(&coords);
// NOTE: Discard off-screen pixels!
// For instance, when we have a halfcell offset in conjunction with a !isPerfectFit pixel offset,
// when we're padding and centering, the final whitespace of right-padding will have its last
// few pixels (the exact amount being half of the dead zone width) pushed off-screen...
// And, of course, anything using hoffset or voffset can happily push stuff OOB ;).
if (unlikely(coords.x >= vInfo.xres || coords.y >= vInfo.yres)) {
# ifdef DEBUG
// NOTE: This is only enabled in Debug builds because it can be pretty verbose,
// and does not necessarily indicate an actual issue, as we've just explained...
LOG("Put: discarding off-screen pixel @ (%hu, %hu) (out of %ux%u bounds)",
coords.x,
coords.y,
vInfo.xres,
vInfo.yres);
# endif
return;
}
// NOTE: Hmm, here, an if ladder appears to be ever so *slightly* faster than going through the function pointer...
if (deviceQuirks.pixelFormat == FBINK_PXFMT_Y4) {
put_pixel_Gray4(&coords, px);
} else if (likely(deviceQuirks.pixelFormat == FBINK_PXFMT_Y8)) {
put_pixel_Gray8(&coords, px);
} else if (vInfo.bits_per_pixel == 16U) {
// Do we need to pack the pixel, first?
if (is_rgb565) {
// Nope :)
put_pixel_RGB565(&coords, px);
} else {
// Yep :(
FBInkPixel packed_px;
// NOTE: Technically legitimate warning. In practice, we always pass RGB32 pixels in 16bpp codepaths.
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wunknown-pragmas"
# pragma clang diagnostic ignored "-Wunknown-warning-option"
# pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
if (likely(deviceQuirks.pixelFormat == FBINK_PXFMT_BGR565)) {
packed_px.rgb565 = pack_bgr565(px->bgra.color.r, px->bgra.color.g, px->bgra.color.b);
} else {
packed_px.rgb565 = pack_rgb565(px->rgba.color.r, px->rgba.color.g, px->rgba.color.b);
}
# pragma GCC diagnostic pop
put_pixel_RGB565(&coords, &packed_px);
}
} else if (unlikely(deviceQuirks.pixelFormat == FBINK_PXFMT_BGR24)) {
put_pixel_BGR24(&coords, px);
} else if (unlikely(deviceQuirks.pixelFormat == FBINK_PXFMT_RGB24)) {
put_pixel_RGB24(&coords, px);
} else if (likely(vInfo.bits_per_pixel == 32U)) {
put_pixel_RGB32(&coords, px);
}
}
// Helper functions to 'get' a specific pixel's color from the framebuffer
// c.f., FBGrab convert* functions
// (http://trac.ak-team.com/trac/browser/niluje/Configs/trunk/Kindle/Misc/FBGrab/fbgrab.c#L402)
// as well as KOReader's routines
// (https://github.com/koreader/koreader-base/blob/b3e72affd0e1ba819d92194b229468452c58836f/ffi/blitbuffer.lua#L292)
static inline __attribute__((always_inline, hot)) void
get_pixel_Gray4(const FBInkCoordinates* restrict coords, FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
// note: x / 2 as every byte holds 2 pixels
const size_t pix_offset = (coords->x >> 1U) + (coords->y * fInfo.line_length);
// NOTE: Expand 4bpp to 8bpp:
// (v * 0x11)
// Byte to nibble (c.f., https://en.wikipedia.org/wiki/Nibble)
// Hi:
// (((b) >> 4) & 0x0F)
// Lo:
// ((b) & 0x0F)
// We'll need the full byte first...
const uint8_t b = *((const unsigned char*) (fbPtr + pix_offset));
if ((coords->x & 0x01u) == 0U) {
// Even pixel: high nibble
const uint8_t v = (b & 0xF0u);
px->gray8 = (v | (v >> 4U));
// pull the top/left nibble, expanded to 8bit
// or: (uint8_t)((((b) >> 4) & 0x0F) * 0x11);
} else {
// Odd pixel: low nibble
px->gray8 = (uint8_t) ((b & 0x0Fu) * 0x11u);
// or: pull the low/right nibble, expanded to 8bit
}
// NOTE: c.f., FBInkPixel typedef in fbink_types.h for details on the union shenanigans...
// In short: gray8 -> gray4.hi -> bgra.color.b
// gray4.lo -> bgra.color.g
}
static inline __attribute__((always_inline, hot)) void
get_pixel_Gray8(const FBInkCoordinates* restrict coords, FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
const size_t pix_offset = coords->x + (coords->y * fInfo.line_length);
px->gray8 = *((unsigned char*) (fbPtr + pix_offset));
}
static inline __attribute__((always_inline)) void
get_pixel_BGR24(const FBInkCoordinates* restrict coords, FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
// note: x * 3 as every pixel is 3 consecutive bytes
const size_t pix_offset = (coords->x * 3U) + (coords->y * fInfo.line_length);
px->bgra.color.b = *((unsigned char*) (fbPtr + pix_offset));
px->bgra.color.g = *((unsigned char*) (fbPtr + pix_offset + 1U));
px->bgra.color.r = *((unsigned char*) (fbPtr + pix_offset + 2U));
}
static inline __attribute__((always_inline)) void
get_pixel_RGB24(const FBInkCoordinates* restrict coords, FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
// note: x * 3 as every pixel is 3 consecutive bytes
const size_t pix_offset = (coords->x * 3U) + (coords->y * fInfo.line_length);
px->rgba.color.r = *((unsigned char*) (fbPtr + pix_offset));
px->rgba.color.g = *((unsigned char*) (fbPtr + pix_offset + 1U));
px->rgba.color.b = *((unsigned char*) (fbPtr + pix_offset + 2U));
}
static inline __attribute__((always_inline, hot)) void
get_pixel_RGB32(const FBInkCoordinates* restrict coords, FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
const size_t scanline_offset = (size_t) coords->y * fInfo.line_length;
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wcast-align"
px->p = *((uint32_t*) (fbPtr + scanline_offset) + coords->x);
# pragma GCC diagnostic pop
// NOTE: We generally don't care about alpha, we always assume it's opaque, as that's how it behaves.
// We *do* pickup the actual alpha value, here, though.
}
static inline __attribute__((always_inline, hot)) void
get_pixel_BGR565(const FBInkCoordinates* restrict coords, FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
const size_t scanline_offset = (size_t) coords->y * fInfo.line_length;
// NOTE: We're honoring the fb's bitfield offsets here (B: 0, G: >> 5, R: >> 11)
// Like put_pixel_RGB565, read those two consecutive bytes at once
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wcast-align"
const uint16_t v = *((const uint16_t*) (fbPtr + scanline_offset) + coords->x);
# pragma GCC diagnostic pop
// NOTE: Unpack to RGB32, because we have no use for BGR565, it's terrible.
// NOTE: c.f., https://stackoverflow.com/q/2442576
// I feel that this approach tracks better with what we do in pack_bgr565,
// and I have an easier time following it than the previous approach ported from KOReader.
// Both do exactly the same thing, though ;).
const uint8_t r = (uint8_t) ((v & 0xF800u) >> 11U); // 11111000 00000000 = 0xF800
const uint8_t g = (v & 0x07E0u) >> 5U; // 00000111 11100000 = 0x07E0
const uint8_t b = (v & 0x001Fu); // 00000000 00011111 = 0x001F
px->bgra.color.r = (uint8_t) ((r << 3U) | (r >> 2U));
px->bgra.color.g = (uint8_t) ((g << 2U) | (g >> 4U));
px->bgra.color.b = (uint8_t) ((b << 3U) | (b >> 2U));
}
static inline __attribute__((always_inline, hot)) void
get_pixel_RGB565(const FBInkCoordinates* restrict coords, FBInkPixel* restrict px)
{
// calculate the pixel's byte offset inside the buffer
const size_t scanline_offset = (size_t) coords->y * fInfo.line_length;
// NOTE: We're honoring the fb's bitfield offsets here (R: 0, G: >> 5, B: >> 11)
// Like put_pixel_RGB565, read those two consecutive bytes at once
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wcast-align"
const uint16_t v = *((const uint16_t*) (fbPtr + scanline_offset) + coords->x);
# pragma GCC diagnostic pop
// NOTE: Unpack to RGB32, because we have no use for RGB565, it's terrible.
// NOTE: c.f., https://stackoverflow.com/q/2442576
// I feel that this approach tracks better with what we do in pack_rgb565,
// and I have an easier time following it than the previous approach ported from KOReader.
// Both do exactly the same thing, though ;).
const uint8_t b = (uint8_t) ((v & 0xF800u) >> 11U); // 11111000 00000000 = 0xF800
const uint8_t g = (v & 0x07E0u) >> 5U; // 00000111 11100000 = 0x07E0
const uint8_t r = (v & 0x001Fu); // 00000000 00011111 = 0x001F
px->rgba.color.r = (uint8_t) ((r << 3U) | (r >> 2U));
px->rgba.color.g = (uint8_t) ((g << 2U) | (g >> 4U));
px->rgba.color.b = (uint8_t) ((b << 3U) | (b >> 2U));
}
// Handle a few sanity checks...
static inline __attribute__((always_inline, hot)) void
get_pixel(FBInkCoordinates coords, FBInkPixel* restrict px)
{
// Handle rotation now, so we can properly validate if the pixel is off-screen or not ;).
// fbink_init() takes care of setting this global pointer to the right function...
(*fxpRotateCoords)(&coords);
// NOTE: Discard off-screen pixels!
// For instance, when we have a halfcell offset in conjunction with a !isPerfectFit pixel offset,
// when we're padding and centering, the final whitespace of right-padding will have its last
// few pixels (the exact amount being half of the dead zone width) pushed off-screen...
// And, of course, anything using hoffset or voffset can happily push stuff OOB ;).
if (unlikely(coords.x >= vInfo.xres || coords.y >= vInfo.yres)) {
# ifdef DEBUG
// NOTE: This is only enabled in Debug builds because it can be pretty verbose,
// and does not necessarily indicate an actual issue, as we've just explained...
LOG("Put: discarding off-screen pixel @ (%hu, %hu) (out of %ux%u bounds)",
coords.x,
coords.y,
vInfo.xres,
vInfo.yres);
# endif
return;
}
// NOTE: Hmm, here, an if ladder appears to be ever so *slightly* faster than going through the function pointer...
if (deviceQuirks.pixelFormat == FBINK_PXFMT_Y4) {
get_pixel_Gray4(&coords, px);
} else if (likely(deviceQuirks.pixelFormat == FBINK_PXFMT_Y8)) {
get_pixel_Gray8(&coords, px);
} else if (deviceQuirks.pixelFormat == FBINK_PXFMT_BGR565) {
get_pixel_BGR565(&coords, px);
} else if (unlikely(deviceQuirks.pixelFormat == FBINK_PXFMT_RGB565)) {
get_pixel_RGB565(&coords, px);
} else if (unlikely(deviceQuirks.pixelFormat == FBINK_PXFMT_BGR24)) {
get_pixel_BGR24(&coords, px);
} else if (unlikely(deviceQuirks.pixelFormat == FBINK_PXFMT_RGB24)) {
get_pixel_RGB24(&coords, px);
} else if (likely(vInfo.bits_per_pixel == 32U)) {
get_pixel_RGB32(&coords, px);
}
}
// Helper functions to draw a rectangle in a given color
static __attribute__((hot)) void
fill_rect_Gray4(unsigned short int x,
unsigned short int y,
unsigned short int w,
unsigned short int h,
const FBInkPixel* restrict px)
{
// Go with pixel plotting @ 4bpp to keep this simple...
for (unsigned short int cy = 0U; cy < h; cy++) {
for (unsigned short int cx = 0U; cx < w; cx++) {
const FBInkCoordinates coords = {
.x = (unsigned short int) (x + cx),
.y = (unsigned short int) (y + cy),
};
put_pixel_Gray4(&coords, px);
}
}
# ifdef DEBUG
LOG("Filled a #%02hhX %hux%hu rectangle @ (%hu, %hu)", px->gray8, w, h, x, y);
# endif
}
static __attribute__((hot)) void
fill_rect_Gray4_checked(unsigned short int x,
unsigned short int y,
unsigned short int w,
unsigned short int h,
const FBInkPixel* restrict px)
{
// Bounds-checking, to ensure the memset won't do stupid things...
// Do signed maths, to account for the fact that x or y might already be OOB!
if (unlikely(x + w > screenWidth)) {
w = (unsigned short int) MAX(0, (w - ((x + w) - (int) screenWidth)));
# ifdef DEBUG
LOG("Chopped rectangle width to %hu", w);
# endif
}
if (unlikely(y + h > screenHeight)) {
h = (unsigned short int) MAX(0, (h - ((y + h) - (int) screenHeight)));
# ifdef DEBUG
LOG("Chopped rectangle height to %hu", h);
# endif
}
// Abort early if that left us with an empty rectangle ;).
if (unlikely(w == 0U || h == 0U)) {
# ifdef DEBUG
LOG("Skipped empty %hux%hu rectangle @ (%hu, %hu)", w, h, x, y);
# endif
return;
}
return fill_rect_Gray4(x, y, w, h, px);
}
# ifdef FBINK_FOR_POCKETBOOK
static __attribute__((hot)) void
fill_rect_Gray8(unsigned short int x,
unsigned short int y,
unsigned short int w,
unsigned short int h,
const FBInkPixel* restrict px)
{
// NOTE: We may require fxpRotateRegion on PB :(.
struct mxcfb_rect region = {
.top = y,
.left = x,
.width = w,
.height = h,
};
(*fxpRotateRegion)(®ion);
for (size_t j = region.top; j < region.top + region.height; j++) {
uint8_t* p = fbPtr + (fInfo.line_length * j) + (region.left);
memset(p, px->gray8, region.width);
}
# ifdef DEBUG
LOG("Filled a #%02hhX %hux%hu rectangle @ (%hu, %hu)", px->gray8, w, h, x, y);
# endif
}
# else
static __attribute__((hot)) void
fill_rect_Gray8(unsigned short int x,
unsigned short int y,
unsigned short int w,
unsigned short int h,
const FBInkPixel* restrict px)
{
// NOTE: fxpRotateRegion is never set at 8bpp :).
for (size_t j = y; j < y + h; j++) {
uint8_t* p = fbPtr + (fInfo.line_length * j) + (x);
memset(p, px->gray8, w);
}
# ifdef DEBUG
LOG("Filled a #%02hhX %hux%hu rectangle @ (%hu, %hu)", px->gray8, w, h, x, y);
# endif
}
# endif
static __attribute__((hot)) void
fill_rect_Gray8_checked(unsigned short int x,
unsigned short int y,
unsigned short int w,
unsigned short int h,
const FBInkPixel* restrict px)
{
// Bounds-checking, to ensure the memset won't do stupid things...
// Do signed maths, to account for the fact that x or y might already be OOB!
if (unlikely(x + w > screenWidth)) {
w = (unsigned short int) MAX(0, (w - ((x + w) - (int) screenWidth)));
# ifdef DEBUG
LOG("Chopped rectangle width to %hu", w);
# endif
}
if (unlikely(y + h > screenHeight)) {
h = (unsigned short int) MAX(0, (h - ((y + h) - (int) screenHeight)));
# ifdef DEBUG
LOG("Chopped rectangle height to %hu", h);
# endif
}
// Abort early if that left us with an empty rectangle ;).
if (unlikely(w == 0U || h == 0U)) {
# ifdef DEBUG
LOG("Skipped empty %hux%hu rectangle @ (%hu, %hu)", w, h, x, y);
# endif
return;
}
return fill_rect_Gray8(x, y, w, h, px);
}
static __attribute__((hot)) void
fill_rect_RGB565(unsigned short int x,
unsigned short int y,
unsigned short int w,
unsigned short int h,
const FBInkPixel* restrict px)
{
// Things are a bit trickier @ 16bpp, because except for black or white, we're not sure the requested color
// will be composed of two indentical bytes when packed as RGB565... -_-".
// NOTE: Silver lining: as fill_rect was originally designed to only ever be fed eInk palette colors,
// we have a guarantee that the input pixel is already packed, so we can use px->rgb565 ;).
struct mxcfb_rect region = {
.top = y,
.left = x,
.width = w,
.height = h,
};
(*fxpRotateRegion)(®ion);
// And that's a cheap-ass manual memset16, let's hope the compiler can do something fun with that...
// That's the exact pattern used by the Linux kernel (c.f., memset16 @ lib/string.c), so, here's hoping ;).
for (size_t j = region.top; j < region.top + region.height; j++) {
const size_t scanline_offset = fInfo.line_length * j;
# pragma GCC diagnostic push
# pragma GCC diagnostic ignored "-Wcast-align"
uint16_t* restrict p = (uint16_t*) (fbPtr + scanline_offset) + region.left;
# pragma GCC diagnostic pop
size_t px_count = region.width;
while (px_count--) {
*p++ = px->rgb565;
}
}
# ifdef DEBUG
LOG("Filled a #%02hhX %hux%hu rectangle @ (%hu, %hu)", px->gray8, w, h, x, y);
# endif
}
static __attribute__((hot)) void
fill_rect_RGB565_checked(unsigned short int x,
unsigned short int y,
unsigned short int w,
unsigned short int h,
const FBInkPixel* restrict px)
{
// Bounds-checking, to ensure the memset won't do stupid things...
// Do signed maths, to account for the fact that x or y might already be OOB!
// NOTE: Unlike put_pixel, we check against screenWidth/screenHeight instead of xres/yres because we're doing this
// *before* fxpRotateRegion!
if (unlikely(x + w > screenWidth)) {
w = (unsigned short int) MAX(0, (w - ((x + w) - (int) screenWidth)));
# ifdef DEBUG
LOG("Chopped rectangle width to %hu", w);
# endif
}
if (unlikely(y + h > screenHeight)) {
h = (unsigned short int) MAX(0, (h - ((y + h) - (int) screenHeight)));
# ifdef DEBUG
LOG("Chopped rectangle height to %hu", h);
# endif
}
// Abort early if that left us with an empty rectangle ;).
if (unlikely(w == 0U || h == 0U)) {
# ifdef DEBUG
LOG("Skipped empty %hux%hu rectangle @ (%hu, %hu)", w, h, x, y);
# endif
return;