qmk-firmware/drivers/painter/tft_panel/qp_tft_panel.c

// Copyright 2021 Nick Brassel (@tzarc)
// SPDX-License-Identifier: GPL-2.0-or-later

#include "color.h"
#include "qp_internal.h"
#include "qp_comms.h"
#include "qp_draw.h"
#include "qp_tft_panel.h"

#define BYTE_SWAP(x) (((((uint16_t)(x)) >> 8) & 0x00FF) | ((((uint16_t)(x)) << 8) & 0xFF00))

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Native pixel format conversion

uint16_t qp_rgb888_to_rgb565(uint8_t r, uint8_t g, uint8_t b) {
    uint16_t rgb565 = (((uint16_t)r) >> 3) << 11 | (((uint16_t)g) >> 2) << 5 | (((uint16_t)b) >> 3);
    return rgb565;
}

uint16_t qp_rgb888_to_rgb565_swapped(uint8_t r, uint8_t g, uint8_t b) {
    uint16_t rgb565 = (((uint16_t)r) >> 3) << 11 | (((uint16_t)g) >> 2) << 5 | (((uint16_t)b) >> 3);
    return BYTE_SWAP(rgb565);
}

uint16_t qp_rgb888_to_bgr565(uint8_t r, uint8_t g, uint8_t b) {
    uint16_t bgr565 = (((uint16_t)b) >> 3) << 11 | (((uint16_t)g) >> 2) << 5 | (((uint16_t)r) >> 3);
    return bgr565;
}

uint16_t qp_rgb888_to_bgr565_swapped(uint8_t r, uint8_t g, uint8_t b) {
    uint16_t bgr565 = (((uint16_t)b) >> 3) << 11 | (((uint16_t)g) >> 2) << 5 | (((uint16_t)r) >> 3);
    return BYTE_SWAP(bgr565);
}

////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Quantum Painter API implementations

// Power control
bool qp_tft_panel_power(painter_device_t device, bool power_on) {
    struct painter_driver_t *                          driver = (struct painter_driver_t *)device;
    struct tft_panel_dc_reset_painter_driver_vtable_t *vtable = (struct tft_panel_dc_reset_painter_driver_vtable_t *)driver->driver_vtable;
    qp_comms_command(device, power_on ? vtable->opcodes.display_on : vtable->opcodes.display_off);
    return true;
}

// Screen clear
bool qp_tft_panel_clear(painter_device_t device) {
    struct painter_driver_t *driver = (struct painter_driver_t *)device;
    driver->driver_vtable->init(device, driver->rotation); // Re-init the LCD
    return true;
}

// Screen flush
bool qp_tft_panel_flush(painter_device_t device) {
    // No-op, as there's no framebuffer in RAM for this device.
    return true;
}

// Viewport to draw to
bool qp_tft_panel_viewport(painter_device_t device, uint16_t left, uint16_t top, uint16_t right, uint16_t bottom) {
    struct painter_driver_t *                          driver = (struct painter_driver_t *)device;
    struct tft_panel_dc_reset_painter_driver_vtable_t *vtable = (struct tft_panel_dc_reset_painter_driver_vtable_t *)driver->driver_vtable;

    // Fix up the drawing location if required
    left += driver->offset_x;
    right += driver->offset_x;
    top += driver->offset_y;
    bottom += driver->offset_y;

    // Check if we need to manually swap the window coordinates based on whether or not we're in a sideways rotation
    if (vtable->swap_window_coords && (driver->rotation == QP_ROTATION_90 || driver->rotation == QP_ROTATION_270)) {
        uint16_t temp;

        temp = left;
        left = top;
        top  = temp;

        temp   = right;
        right  = bottom;
        bottom = temp;
    }

    if (vtable->num_window_bytes == 1) {
        // Set up the x-window
        uint8_t xbuf[2] = {left & 0xFF, right & 0xFF};
        qp_comms_command_databuf(device, vtable->opcodes.set_column_address, xbuf, sizeof(xbuf));

        // Set up the y-window
        uint8_t ybuf[2] = {top & 0xFF, bottom & 0xFF};
        qp_comms_command_databuf(device, vtable->opcodes.set_row_address, ybuf, sizeof(ybuf));
    } else if (vtable->num_window_bytes == 2) {
        // Set up the x-window
        uint8_t xbuf[4] = {left >> 8, left & 0xFF, right >> 8, right & 0xFF};
        qp_comms_command_databuf(device, vtable->opcodes.set_column_address, xbuf, sizeof(xbuf));

        // Set up the y-window
        uint8_t ybuf[4] = {top >> 8, top & 0xFF, bottom >> 8, bottom & 0xFF};
        qp_comms_command_databuf(device, vtable->opcodes.set_row_address, ybuf, sizeof(ybuf));
    }

    // Lock in the window
    qp_comms_command(device, vtable->opcodes.enable_writes);
    return true;
}

// Stream pixel data to the current write position in GRAM
bool qp_tft_panel_pixdata(painter_device_t device, const void *pixel_data, uint32_t native_pixel_count) {
    qp_comms_send(device, pixel_data, native_pixel_count * sizeof(uint16_t));
    return true;
}

// Convert supplied palette entries into their native equivalents
bool qp_tft_panel_palette_convert(painter_device_t device, int16_t palette_size, qp_pixel_t *palette) {
    struct painter_driver_t *                          driver = (struct painter_driver_t *)device;
    struct tft_panel_dc_reset_painter_driver_vtable_t *vtable = (struct tft_panel_dc_reset_painter_driver_vtable_t *)driver->driver_vtable;
    for (int16_t i = 0; i < palette_size; ++i) {
        RGB rgb           = hsv_to_rgb_nocie((HSV){palette[i].hsv888.h, palette[i].hsv888.s, palette[i].hsv888.v});
        palette[i].rgb565 = vtable->rgb888_to_native16bit(rgb.r, rgb.g, rgb.b);
    }
    return true;
}

// Append pixels to the target location, keyed by the pixel index
bool qp_tft_panel_append_pixels(painter_device_t device, uint8_t *target_buffer, qp_pixel_t *palette, uint32_t pixel_offset, uint32_t pixel_count, uint8_t *palette_indices) {
    uint16_t *buf = (uint16_t *)target_buffer;
    for (uint32_t i = 0; i < pixel_count; ++i) {
        buf[pixel_offset + i] = palette[palette_indices[i]].rgb565;
    }
    return true;
}