libwebsockets/lib/drivers/display/lws-display.c
Andy Green e3dca87f23 lws_display: add display list / DLO support
This adds optional display list support to lws_display, using DLOs (Display
List Objects).  DLOs for rectangle / rounded rectangle (with circle as the
degenerate case), PNGs, JPEG and compressed, antialiased bitmapped fonts
and text primitives are provided.

Logical DLOs are instantiated on heap and listed into an lws_display_list
owner, DLOs handle attributes like position, bounding box, colour +
opacity, and local error diffusion backing buffer.

When the display list is complete, it can be rasterized a line at a time,
with scoped error diffusion resolved, such that no allocation for the
framebuffer is required at any point.  DLOs are freed as the rasterization
moves beyond their bounding box.

Adds a platform registry binding names and other metadata to lws_display
fonts / PNGs / JPEGs.  Provides registration, destruction and best match
selection apis.
2022-03-25 08:18:29 +00:00

444 lines
12 KiB
C

/*
* lws abstract display
*
* Copyright (C) 2019 - 2022 Andy Green <andy@warmcat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include <private-lib-core.h>
static void
sul_autodim_cb(lws_sorted_usec_list_t *sul)
{
lws_display_state_t *lds = lws_container_of(sul, lws_display_state_t,
sul_autodim);
int next_ms = -1;
/* we fire both to dim and to blank... if already in dim state, blank */
switch (lds->state) {
case LWSDISPS_BECOMING_ACTIVE:
lws_display_state_set_brightness(lds, lds->disp->bl_active);
lds->state = LWSDISPS_ACTIVE;
next_ms = lds->autodim_ms;
break;
case LWSDISPS_ACTIVE:
/* active -> autodimmed */
lds->state = LWSDISPS_AUTODIMMED;
next_ms = lds->off_ms;
lws_display_state_set_brightness(lds, lds->disp->bl_dim);
break;
case LWSDISPS_AUTODIMMED:
/* dimmed -> OFF */
lws_display_state_set_brightness(lds, &lws_pwmseq_static_off);
lds->state = LWSDISPS_GOING_OFF;
next_ms = 600;
break;
case LWSDISPS_GOING_OFF:
/* off dimming completed, actual display OFF */
lws_display_state_off(lds);
return;
default:
return;
}
if (next_ms >= 0)
lws_sul_schedule(lds->ctx, 0, &lds->sul_autodim, sul_autodim_cb,
next_ms * LWS_US_PER_MS);
}
void
lws_display_state_init(lws_display_state_t *lds, struct lws_context *ctx,
int dim_ms, int off_ms, struct lws_led_state *bl_lcs,
const lws_display_t *disp)
{
memset(lds, 0, sizeof(*lds));
lds->disp = disp;
lds->ctx = ctx;
lds->autodim_ms = dim_ms;
lds->off_ms = off_ms;
lds->bl_lcs = bl_lcs;
lds->state = LWSDISPS_OFF;
if (lds->bl_lcs)
lws_led_transition(lds->bl_lcs, "backlight", &lws_pwmseq_static_off,
&lws_pwmseq_static_on);
disp->init(lds);
}
void
lws_display_state_set_brightness(lws_display_state_t *lds,
const lws_led_sequence_def_t *pwmseq)
{
if (lds->bl_lcs)
lws_led_transition(lds->bl_lcs, "backlight", pwmseq,
lds->disp->bl_transition);
}
void
lws_display_state_active(lws_display_state_t *lds)
{
int waiting_ms;
if (lds->state == LWSDISPS_OFF) {
/* power us up */
lds->disp->power(lds, 1);
lds->state = LWSDISPS_BECOMING_ACTIVE;
waiting_ms = lds->disp->latency_wake_ms;
} else {
if (lds->state != LWSDISPS_ACTIVE && lds->bl_lcs)
lws_display_state_set_brightness(lds,
lds->disp->bl_active);
lds->state = LWSDISPS_ACTIVE;
waiting_ms = lds->autodim_ms;
}
/* reset the autodim timer */
if (waiting_ms >= 0)
lws_sul_schedule(lds->ctx, 0, &lds->sul_autodim, sul_autodim_cb,
waiting_ms * LWS_US_PER_MS);
}
void
lws_display_state_off(lws_display_state_t *lds)
{
/* if no control over backlight, don't bother power down display
* since it would continue to emit, just show all-white or whatever */
if (lds->bl_lcs)
lds->disp->power(lds, 0);
lws_sul_cancel(&lds->sul_autodim);
lds->state = LWSDISPS_OFF;
}
int
lws_display_alloc_diffusion(const lws_surface_info_t *ic, lws_surface_error_t **se)
{
size_t size, gsize = ic->greyscale ? sizeof(lws_greyscale_error_t) :
sizeof(lws_colour_error_t), by;
if (*se)
return 0;
/* defer creation of dlo's 2px-high dlo-width, 2 bytespp or 6 bytespp
* error diffusion buffer */
by = ((ic->wh_px[0].whole + 15) / 8) * 8;
size = gsize * 2u * (unsigned int)by;
lwsl_info("%s: alloc'd %u for width %d\n", __func__, (unsigned int)size,
(int)ic->wh_px[0].whole);
se[0] = lws_zalloc(size, __func__);
if (!se[0])
return 1;
se[1] = (lws_surface_error_t *)(((uint8_t *)se[0]) + (size / 2));
return 0;
}
static void
dist_err_grey(const lws_greyscale_error_t *in, lws_greyscale_error_t *out,
int sixteenths)
{
out->rgb[0] = (int16_t)(out->rgb[0] +
(int16_t)((sixteenths * in->rgb[0]) / 16));
}
static void
dist_err_col(const lws_colour_error_t *in, lws_colour_error_t *out,
int sixteenths)
{
out->rgb[0] = (int16_t)(out->rgb[0] +
(int16_t)((sixteenths * in->rgb[0]) / 16));
out->rgb[1] = (int16_t)(out->rgb[1] +
(int16_t)((sixteenths * in->rgb[1]) / 16));
out->rgb[2] = (int16_t)(out->rgb[2] +
(int16_t)((sixteenths * in->rgb[2]) / 16));
}
void
dist_err_floyd_steinberg_grey(int n, int width, lws_greyscale_error_t *gedl_this,
lws_greyscale_error_t *gedl_next)
{
if (n < width - 1) {
dist_err_grey(&gedl_this[n], &gedl_this[n + 1], 7);
dist_err_grey(&gedl_this[n], &gedl_next[n + 1], 1);
}
if (n)
dist_err_grey(&gedl_this[n], &gedl_next[n - 1], 3);
dist_err_grey(&gedl_this[n], &gedl_next[n], 5);
gedl_this[n].rgb[0] = 0;
}
void
dist_err_floyd_steinberg_col(int n, int width, lws_colour_error_t *edl_this,
lws_colour_error_t *edl_next)
{
if (n < width - 1) {
dist_err_col(&edl_this[n], &edl_this[n + 1], 7);
dist_err_col(&edl_this[n], &edl_next[n + 1], 1);
}
if (n)
dist_err_col(&edl_this[n], &edl_next[n - 1], 3);
dist_err_col(&edl_this[n], &edl_next[n], 5);
edl_this[n].rgb[0] = 0;
edl_this[n].rgb[1] = 0;
edl_this[n].rgb[2] = 0;
}
/*
* #include <stdio.h>
* #include <math.h>
*
* void
* main(void)
* {
* int n;
*
* for (n = 0; n < 256; n++) {
* double d = (double)n / 255.0;
*
* printf("0x%02X, ", (unsigned int)(pow(d, (2.2)) * 255));
* }
*
* }
*/
static const uint8_t gamma2_2[] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x01,
0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02, 0x02,
0x02, 0x02, 0x03, 0x03, 0x03, 0x03, 0x03, 0x04,
0x04, 0x04, 0x04, 0x05, 0x05, 0x05, 0x05, 0x06,
0x06, 0x06, 0x07, 0x07, 0x07, 0x08, 0x08, 0x08,
0x09, 0x09, 0x09, 0x0A, 0x0A, 0x0A, 0x0B, 0x0B,
0x0C, 0x0C, 0x0D, 0x0D, 0x0D, 0x0E, 0x0E, 0x0F,
0x0F, 0x10, 0x10, 0x11, 0x11, 0x12, 0x12, 0x13,
0x13, 0x14, 0x15, 0x15, 0x16, 0x16, 0x17, 0x17,
0x18, 0x19, 0x19, 0x1A, 0x1B, 0x1B, 0x1C, 0x1D,
0x1D, 0x1E, 0x1F, 0x1F, 0x20, 0x21, 0x21, 0x22,
0x23, 0x24, 0x24, 0x25, 0x26, 0x27, 0x28, 0x28,
0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2D, 0x2E, 0x2F,
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E,
0x3F, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
0x48, 0x49, 0x4A, 0x4B, 0x4D, 0x4E, 0x4F, 0x50,
0x51, 0x52, 0x54, 0x55, 0x56, 0x57, 0x58, 0x5A,
0x5B, 0x5C, 0x5D, 0x5F, 0x60, 0x61, 0x63, 0x64,
0x65, 0x67, 0x68, 0x69, 0x6B, 0x6C, 0x6D, 0x6F,
0x70, 0x72, 0x73, 0x75, 0x76, 0x77, 0x79, 0x7A,
0x7C, 0x7D, 0x7F, 0x80, 0x82, 0x83, 0x85, 0x87,
0x88, 0x8A, 0x8B, 0x8D, 0x8E, 0x90, 0x92, 0x93,
0x95, 0x97, 0x98, 0x9A, 0x9C, 0x9D, 0x9F, 0xA1,
0xA2, 0xA4, 0xA6, 0xA8, 0xA9, 0xAB, 0xAD, 0xAF,
0xB0, 0xB2, 0xB4, 0xB6, 0xB8, 0xBA, 0xBB, 0xBD,
0xBF, 0xC1, 0xC3, 0xC5, 0xC7, 0xC9, 0xCB, 0xCD,
0xCF, 0xD1, 0xD3, 0xD5, 0xD7, 0xD9, 0xDB, 0xDD,
0xDF, 0xE1, 0xE3, 0xE5, 0xE7, 0xE9, 0xEB, 0xED,
0xEF, 0xF1, 0xF4, 0xF6, 0xF8, 0xFA, 0xFC, 0xFF
};
lws_display_palette_idx_t
lws_display_palettize_grey(const lws_surface_info_t *ic,
const lws_display_colour_t *palette, size_t pdepth,
lws_display_colour_t c, lws_greyscale_error_t *ectx)
{
int best = 0x7fffffff, best_idx = 0;
lws_colour_error_t da, d, ea;
int sum, y;
size_t n;
/* put the most desirable colour (adjusted for existing error) in d */
d.rgb[0] = (int)gamma2_2[LWSDC_R(c)];
da.rgb[0] = d.rgb[0] + ectx->rgb[0];
if (da.rgb[0] < 0)
da.rgb[0] = 0;
if (da.rgb[0] > 255)
da.rgb[0] = 255;
if (ic->type == LWSSURF_565) {
y = d.rgb[0] >> 3;
ectx->rgb[0] = (int16_t)((int)da.rgb[0] - y);
return (lws_display_palette_idx_t)y;
}
/*
* Choose a palette colour considering the error diffusion adjustments
*/
for (n = 0; n < pdepth; n++) {
y = LWSDC_ALPHA(palette[n]);
ea.rgb[0] = (int16_t)((int)da.rgb[0] - (int)(LWSDC_R(palette[n])));
sum = ea.rgb[0] < 0 ? -ea.rgb[0] : ea.rgb[0];
if (sum < best) {
best_idx = (int)n;
best = sum;
}
}
/* report the error between the unadjusted colour and what we chose */
ectx->rgb[0] = (int16_t)((int)da.rgb[0] - (int)(LWSDC_R(palette[best_idx])));
return (lws_display_palette_idx_t)best_idx;
}
/*
* For error disffusion, it's better to use YUV and prioritize reducing error
* in Y (lumience)
*/
#if 0
static void
rgb_to_yuv(uint8_t *yuv, const uint8_t *rgb)
{
yuv[0] = 16 + ((257 * rgb[0]) / 1000) + ((504 * rgb[1]) / 1000) +
((98 * rgb[2]) / 1000);
yuv[1] = 128 - ((148 * rgb[0]) / 1000) - ((291 * rgb[1]) / 1000) +
((439 * rgb[2]) / 1000);
yuv[2] = 128 + ((439 * rgb[0]) / 1000) - ((368 * rgb[1]) / 1000) -
((71 * rgb[2]) / 1000);
}
static void
yuv_to_rgb(uint8_t *rgb, const uint8_t *_yuv)
{
unsigned int yuv[3];
yuv[0] = _yuv[0] - 16;
yuv[1] = _yuv[1] - 128;
yuv[2] = _yuv[2] - 128;
rgb[0] = ((1164 * yuv[0]) / 1000) + ((1596 * yuv[2]) / 1000);
rgb[1] = ((1164 * yuv[0]) / 1090) - ((392 * yuv[1]) / 1000) -
((813 * yuv[2]) / 1000);
rgb[2] = ((1164 * yuv[0]) / 1000) + ((2017 * yuv[1]) / 1000);
}
#endif
lws_display_palette_idx_t
lws_display_palettize_col(const lws_surface_info_t *ic,
const lws_display_colour_t *palette, size_t pdepth,
lws_display_colour_t c, lws_colour_error_t *ectx)
{
int best = 0x7fffffff, best_idx = 0, yd;
lws_colour_error_t da, d;
uint8_t ya[3];
size_t n;
int y, ch;
/* put the most desirable colour (adjusted for existing error) in d */
d.rgb[0] = (int)gamma2_2[LWSDC_R(c)];
da.rgb[0] = d.rgb[0] + ectx->rgb[0];
if (da.rgb[0] < 0)
da.rgb[0] = 0;
if (da.rgb[0] > 255)
da.rgb[0] = 255;
yd = da.rgb[0];
d.rgb[1] = (int)gamma2_2[LWSDC_G(c)];
d.rgb[2] = (int)gamma2_2[LWSDC_B(c)];
da.rgb[1] = d.rgb[1] + ectx->rgb[1];
if (da.rgb[1] < 0)
da.rgb[1] = 0;
if (da.rgb[1] > 255)
da.rgb[1] = 255;
da.rgb[2] = d.rgb[2] + ectx->rgb[2];
if (da.rgb[2] < 0)
da.rgb[2] = 0;
if (da.rgb[2] > 255)
da.rgb[2] = 255;
yd = RGB_TO_Y(da.rgb[0], da.rgb[1], da.rgb[2]);
if (ic->type == LWSSURF_565) {
ya[0] = d.rgb[0] >> 3;
ectx->rgb[0] = (int16_t)((int)da.rgb[0] - (ya[0] << 3));
ya[1] = d.rgb[1] >> 2;
ectx->rgb[1] = (int16_t)((int)da.rgb[1] - (ya[1] << 2));
ya[2] = d.rgb[2] >> 3;
ectx->rgb[2] = (int16_t)((int)da.rgb[2] - (ya[2] << 3));
return (lws_display_palette_idx_t)((ya[0] << 11) | (ya[1] << 5) | (ya[2]));
}
/*
* Choose a palette colour considering the error diffusion adjustments,
* separately choose the best Y match and the best RGB match
*/
for (n = 0; n < pdepth; n++) {
lws_colour_error_t ea;
int sum;
y = LWSDC_ALPHA(palette[n]);
ea.rgb[0] = (int16_t)((int)da.rgb[0] - (int)(LWSDC_R(palette[n])));
ea.rgb[1] = (int16_t)((int)da.rgb[1] - (int)(LWSDC_G(palette[n])));
ea.rgb[2] = (int16_t)((int)da.rgb[2] - (int)(LWSDC_B(palette[n])));
/* Best considering luma match */
sum = (yd > y ? (yd - y) : (y - yd));
/*
* Best considering RGB matching
*/
sum += ((ea.rgb[0] < 0 ? -ea.rgb[0] : ea.rgb[0]) +
(ea.rgb[1] < 0 ? -ea.rgb[1] : ea.rgb[1]) +
(ea.rgb[2] < 0 ? -ea.rgb[2] : ea.rgb[2]));
if (sum < best) {
best_idx = (int)n;
best = sum;
}
}
ch = best_idx;
/* report the error between the adjusted colour and what we chose */
ectx->rgb[0] = (int16_t)((int)da.rgb[0] - (int)(LWSDC_R(palette[ch])));
ectx->rgb[1] = (int16_t)((int)da.rgb[1] - (int)(LWSDC_G(palette[ch])));
ectx->rgb[2] = (int16_t)((int)da.rgb[2] - (int)(LWSDC_B(palette[ch])));
return (lws_display_palette_idx_t)ch;
}