timely-reference/DisplayDriver.cpp

/*
 * Copyright (C) 2019  Max Regan
 *
 * 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 "DisplayDriver.h"
#include "macros.h"
#include "font.h"

namespace BSP {

using Common::Schedule::NextTime;
using Common::ReturnCode;

DisplayDriver::DisplayDriver(Common::Schedule::TaskScheduler &scheduler, SpiDriver &spi)
    : m_scheduler(scheduler)
    , m_spi(spi)
    , m_is_dirty(true)
    , m_dirty_line_min(0)
    , m_dirty_line_max(0)
{
    buffer_init();
}

ReturnCode DisplayDriver::init()
{
        /** Enable Port A,B clock */
        SET(RCC->IOPENR, RCC_IOPENR_IOPBEN);
        /** Enable pin P3 for output */
        SET_TO(GPIOB->MODER,
               GPIO_MODER_MODE3,
               GPIO_MODER_MODE3_0);

        CLR(GPIOB->OTYPER, GPIO_OTYPER_OT_3);
        CLR(GPIOB->PUPDR, GPIO_PUPDR_PUPD3);

        return Common::ReturnCode::OK;


    return ReturnCode::OK;
}

NextTime DisplayDriver::execute()
{
    return NextTime::never();
}

void DisplayDriver::buffer_init()
{
    for (size_t i = 0; i < ARRAY_SIZE(m_buffer.lines); i++) {
        struct display_line *line = &m_buffer.lines[i];
        line->mode = 1; // Update display
        line->line = i;
        for (size_t j = 0; j < ARRAY_SIZE(line->data); j++) {
            line->data[j] = 0xFF;
        }
    }

    m_buffer.dummy = 0;
}

void DisplayDriver::set_dirty(unsigned int y)
{
    if (!m_is_dirty) {
        m_is_dirty = true;
        m_dirty_line_min = y;
        m_dirty_line_max = y;
    } else {
        m_dirty_line_min = MIN(y, m_dirty_line_min);
        m_dirty_line_max = MAX(y, m_dirty_line_max);
    }
}

void DisplayDriver::set_bit(unsigned int x, unsigned int y, uint8_t val)
{
    if (x >= DISPLAY_WIDTH || y >= DISPLAY_HEIGHT) {
        return;
    }

    struct display_line *line = &m_buffer.lines[y];
    uint8_t *byte = &line->data[x >> 3];
    if (val) {
        CLR_POS(*byte, x & 7);
    } else {
        SET_POS(*byte, x & 7);
    }

    set_dirty(y);
}

void DisplayDriver::set_byte(unsigned int x, unsigned int y, uint8_t val)
{
    if (x >= DISPLAY_WIDTH || y >= DISPLAY_HEIGHT) {
        return;
    }

    if (x & 7) {
        return;
    }

    struct display_line *line = &m_buffer.lines[y];
    line->data[x >> 3] = val;
    set_dirty(y);
}

void DisplayDriver::char_at(int *x_off, int y_off, char c, const struct font *font)
{
    const struct glyph *g = glyph_for_char(font, c);
    if (g == NULL) {
        return;
    }

    // TODO: Don't hardcode this
    int byte_cols = (g->cols /  8);
    if (g->cols & 7) {
        byte_cols++;
    }
    if (byte_cols & 1) {
        byte_cols++;
    }
    for (size_t x = 0; x < g->cols; x++) {
        for (size_t y = 0; y < g->rows; y++) {
            int byte_x = x >> 3;
            int byte_y = y;
            uint8_t bit = (g->bitmap[byte_y * byte_cols + byte_x] >> (7 - (x & 7))) & 1;
            /* 16 is font max height */
            set_bit(g->left + *x_off + x, y_off + y + 16 - g->top, bit);
        }
    }
    *x_off += g->advance;
}

void DisplayDriver::string_at(int x_off, int y_off, const char *string, const struct font *font)
{
    int i = 0;
    while (string[i]) {
        char_at(&x_off, y_off, string[i], font);
        i++;
    }
}

void DisplayDriver::refresh()
{
    if (!m_is_dirty) {
        return;
    }

    uint8_t *start = (uint8_t *) &m_buffer.lines[m_dirty_line_min];
    // Data size
    size_t size = sizeof(m_buffer.lines[0]) * (m_dirty_line_max - m_dirty_line_min + 1);
    // Trailer dummy data
    size += 2;

    m_spi.tx_blocking(start, size);
    m_is_dirty = false;
}

void DisplayDriver::clear()
{
    buffer_init();
    m_is_dirty = true;
    m_dirty_line_min = 0;
    m_dirty_line_max = DISPLAY_HEIGHT - 1;
}

//TODO: put me somewhere fonty
const struct glyph *DisplayDriver::glyph_for_char(const struct font *font, char c)
{
    // TODO: This is almost the least efficient way imaginable to implement this
    for (int i = 0; i < font->max; i++) {
        const struct glyph *g = font->glyphs[i];
        if (g == NULL) {
            continue;
        }

        if (g->glyph == c) {
            return g;
        }
    }

    return NULL;
}


}