lws-display.h

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/*
 * 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.
 */
 
#if !defined(__LWS_DISPLAY_H__)
#define __LWS_DISPLAY_H__
 
typedef int16_t lws_display_list_coord_t;
typedef uint16_t lws_display_scalar;
typedef uint16_t lws_display_rotation_t;
typedef uint32_t lws_display_colour_t;
typedef uint16_t lws_display_palette_idx_t;
 
typedef struct lws_box {
        lws_fx_t                x;
        lws_fx_t                y;
        lws_fx_t                w;
        lws_fx_t                h;
} lws_box_t;
 
struct lws_display_state;
struct lws_display;
 
typedef enum {
        LWSSURF_TRUECOLOR32,
        LWSSURF_565,
        LWSSURF_PALETTE,
        LWSSURF_QUANTIZED_4BPP
} lws_surface_type_t;
 
typedef struct lws_surface_info {
        lws_fx_t                        wh_px[2];
        lws_fx_t                        wh_mm[2];
        const lws_display_colour_t      *palette;
        size_t                          palette_depth;
        lws_surface_type_t              type;
        uint8_t                         greyscale:1; /* line: 0 = RGBA, 1 = YA */
        uint8_t                         partial:1; /* can handle partial */
} lws_surface_info_t;
 
typedef struct lws_greyscale_error {
        int16_t                         rgb[1];
} lws_greyscale_error_t;
 
typedef struct lws_colour_error {
        int16_t                         rgb[3];
} lws_colour_error_t;
 
typedef union {
        lws_greyscale_error_t           grey;   /* when ic->greyscale set */
        lws_colour_error_t              colour; /* when ic->greyscale == 0 */
} lws_surface_error_t;
 
LWS_VISIBLE LWS_EXTERN void
lws_surface_set_px(const lws_surface_info_t *ic, uint8_t *line, int x,
                   const lws_display_colour_t *c);
 
LWS_VISIBLE LWS_EXTERN 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);
 
LWS_VISIBLE LWS_EXTERN 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);
 
/*
 * This is embedded in the actual display implementation object at the top,
 * so a pointer to this can be cast to a pointer to the implementation object
 * by any code that is specific to how it was implemented.
 *
 * Notice for the backlight / display intensity we contain pwm_ops... these can
 * be some other pwm_ops like existing gpio pwm ops, or handled in a customized
 * way like set oled contrast.  Either way, the pwm level is arrived at via a
 * full set of lws_led_sequences capable of generic lws transitions
 */
 
typedef struct lws_display {
        int (*init)(struct lws_display_state *lds);
        const lws_pwm_ops_t             *bl_pwm_ops;
        int (*contrast)(struct lws_display_state *lds, uint8_t contrast);
        int (*blit)(struct lws_display_state *lds, const uint8_t *src,
                    lws_box_t *box, lws_dll2_owner_t *ids);
        int (*power)(struct lws_display_state *lds, int state);
 
        const lws_led_sequence_def_t    *bl_active;
        const lws_led_sequence_def_t    *bl_dim;
        const lws_led_sequence_def_t    *bl_transition;
 
        const char                      *name;
        void                            *variant;
 
        int                             bl_index;
 
        lws_surface_info_t              ic;
 
        uint16_t                        latency_wake_ms;
        /**< ms required after wake from sleep before display usable again...
         * delay bringing up the backlight for this amount of time on wake.
         * This is managed via a sul on the event loop, not blocking. */
        uint16_t                        latency_update_ms;
        /**< nominal update latency in ms */
} lws_display_t;
 
/*
 * This contains dynamic data related to display state
 */
 
enum lws_display_controller_state {
        LWSDISPS_OFF,
        LWSDISPS_AUTODIMMED,      /* is in pre- blanking static dim mode */
        LWSDISPS_BECOMING_ACTIVE, /* waiting for wake latency before active */
        LWSDISPS_ACTIVE,          /* is active */
        LWSDISPS_GOING_OFF        /* dimming then off */
};
 
typedef struct lws_display_state {
 
        lws_sorted_usec_list_t          sul_autodim;
 
        char                            current_url[96];
 
        const lws_display_t             *disp;
        struct lws_context              *ctx;
 
        void                            *priv; /* subclass driver alloc'd priv */
 
        int                             autodim_ms;
        int                             off_ms;
 
        struct lws_led_state            *bl_lcs;
 
        lws_led_state_chs_t             chs;
        /* set of sequencer transition channels */
 
        enum lws_display_controller_state state;
 
        char                            display_busy;
 
} lws_display_state_t;
 
/* Used for async display driver events, eg, EPD refresh completion */
typedef int (*lws_display_completion_t)(lws_display_state_t *lds, int a);
 
/**
 * lws_display_state_init() - initialize display states
 *
 * \param lds: the display state object
 * \param ctx: the lws context
 * \param autodim_ms: ms since last active report to dim display (<0 = never)
 * \param off_ms: ms since dim to turn display off (<0 = never)
 * \param bl_lcs: the led controller instance that has the backlight
 * \param disp: generic display object we belong to
 *
 * This initializes a display's state, and sets up the optional screen auto-dim
 * and blanking on inactive, and gradual brightness change timer.
 *
 *  - auto-dim then off: set autodim to some ms and off_ms to some ms
 *  - auto-dim only: set autodim to some ms and off_ms to -1
 *  - off-only: set autodim to some ms and off_ms to 0
 *  - neither: set both autodim and off_ms to -1
 */
LWS_VISIBLE LWS_EXTERN void
lws_display_state_init(lws_display_state_t *lds, struct lws_context *ctx,
                       int autodim_ms, int off_ms, struct lws_led_state *bl_lcs,
                       const lws_display_t *disp);
 
/**
 * lws_display_state_set_brightness() - gradually change the brightness
 *
 * \param lds: the display state we are changing
 * \param target: the target brightness to transition to
 *
 * Adjusts the brightness gradually twoards the target at 20Hz
 */
LWS_VISIBLE LWS_EXTERN void
lws_display_state_set_brightness(lws_display_state_t *lds,
                                 const lws_led_sequence_def_t *pwmseq);
 
/*
 * lws_display_state_active() - inform the system the display is active
 *
 * \param lds: the display state we are marking as active
 *
 * Resets the auto-dim and auto-off timers and makes sure the display is on and
 * at the active brightness level
 */
LWS_VISIBLE LWS_EXTERN void
lws_display_state_active(lws_display_state_t *lds);
 
/*
 * lws_display_state_off() - turns off the related display
 *
 * \param lds: the display state we are turning off
 *
 * Turns the display to least power mode or completely off if possible.
 * Disables the timers related to dimming and blanking.
 */
LWS_VISIBLE LWS_EXTERN void
lws_display_state_off(lws_display_state_t *lds);
 
#endif