raspi3-tutorial/0A_pcscreenfont/lfb.c

/*
 * Copyright (C) 2018 bzt (bztsrc@github)
 *
 * 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 "uart.h"
#include "mbox.h"
#include "delays.h"

/* PC Screen Font as used by Linux Console */
typedef struct {
    unsigned int magic;
    unsigned int version;
    unsigned int headersize;
    unsigned int flags;
    unsigned int numglyph;
    unsigned int bytesperglyph;
    unsigned int height;
    unsigned int width;
    unsigned char glyphs;
} __attribute__((packed)) psf_t;
extern volatile unsigned char _binary_font_psf_start;

/* Scalable Screen Font (https://gitlab.com/bztsrc/scalable-font2) */
typedef struct {
    unsigned char  magic[4];
    unsigned int   size;
    unsigned char  type;
    unsigned char  features;
    unsigned char  width;
    unsigned char  height;
    unsigned char  baseline;
    unsigned char  underline;
    unsigned short fragments_offs;
    unsigned int   characters_offs;
    unsigned int   ligature_offs;
    unsigned int   kerning_offs;
    unsigned int   cmap_offs;
} __attribute__((packed)) sfn_t;
extern volatile unsigned char _binary_font_sfn_start;

unsigned int width, height, pitch;
unsigned char *lfb;

/**
 * Set screen resolution to 1024x768
 */
void lfb_init()
{
    /* newer qemu segfaults if we don't wait here a bit */
    wait_msec(100000);

    mbox[0] = 35*4;
    mbox[1] = MBOX_REQUEST;

    mbox[2] = 0x48003;  //set phy wh
    mbox[3] = 8;
    mbox[4] = 8;
    mbox[5] = 1024;         //FrameBufferInfo.width
    mbox[6] = 768;          //FrameBufferInfo.height

    mbox[7] = 0x48004;  //set virt wh
    mbox[8] = 8;
    mbox[9] = 8;
    mbox[10] = 1024;        //FrameBufferInfo.virtual_width
    mbox[11] = 768;         //FrameBufferInfo.virtual_height

    mbox[12] = 0x48009; //set virt offset
    mbox[13] = 8;
    mbox[14] = 8;
    mbox[15] = 0;           //FrameBufferInfo.x_offset
    mbox[16] = 0;           //FrameBufferInfo.y.offset

    mbox[17] = 0x48005; //set depth
    mbox[18] = 4;
    mbox[19] = 4;
    mbox[20] = 32;          //FrameBufferInfo.depth

    mbox[21] = 0x48006; //set pixel order
    mbox[22] = 4;
    mbox[23] = 4;
    mbox[24] = 1;           //RGB, not BGR preferably

    mbox[25] = 0x40001; //get framebuffer, gets alignment on request
    mbox[26] = 8;
    mbox[27] = 8;
    mbox[28] = 4096;        //FrameBufferInfo.pointer
    mbox[29] = 0;           //FrameBufferInfo.size

    mbox[30] = 0x40008; //get pitch
    mbox[31] = 4;
    mbox[32] = 4;
    mbox[33] = 0;           //FrameBufferInfo.pitch

    mbox[34] = MBOX_TAG_LAST;

    if(mbox_call(MBOX_CH_PROP) && mbox[20]==32 && mbox[28]!=0) {
        mbox[28]&=0x3FFFFFFF;
        width=mbox[5];
        height=mbox[6];
        pitch=mbox[33];
        lfb=(void*)((unsigned long)mbox[28]);
    } else {
        uart_puts("Unable to set screen resolution to 1024x768x32\n");
    }
}

/**
 * Display a string using fixed size PSF
 */
void lfb_print(int x, int y, char *s)
{
    // get our font
    psf_t *font = (psf_t*)&_binary_font_psf_start;
    // draw next character if it's not zero
    while(*s) {
        // get the offset of the glyph. Need to adjust this to support unicode table
        unsigned char *glyph = (unsigned char*)&_binary_font_psf_start +
         font->headersize + (*((unsigned char*)s)<font->numglyph?*s:0)*font->bytesperglyph;
        // calculate the offset on screen
        int offs = (y * pitch) + (x * 4);
        // variables
        int i,j, line,mask, bytesperline=(font->width+7)/8;
        // handle carrige return
        if(*s == '\r') {
            x = 0;
        } else
        // new line
        if(*s == '\n') {
            x = 0; y += font->height;
        } else {
            // display a character
            for(j=0;j<font->height;j++){
                // display one row
                line=offs;
                mask=1<<(font->width-1);
                for(i=0;i<font->width;i++){
                    // if bit set, we use white color, otherwise black
                    *((unsigned int*)(lfb + line))=((int)*glyph) & mask?0xFFFFFF:0;
                    mask>>=1;
                    line+=4;
                }
                // adjust to next line
                glyph+=bytesperline;
                offs+=pitch;
            }
            x += (font->width+1);
        }
        // next character
        s++;
    }
}

/**
 * Display a string using proportional SSFN
 */
void lfb_proprint(int x, int y, char *s)
{
    // get our font
    sfn_t *font = (sfn_t*)&_binary_font_sfn_start;
    unsigned char *ptr, *chr, *frg;
    unsigned int c;
    unsigned long o, p;
    int i, j, k, l, m, n;

    while(*s) {
        // UTF-8 to UNICODE code point
        if((*s & 128) != 0) {
            if(!(*s & 32)) { c = ((*s & 0x1F)<<6)|(*(s+1) & 0x3F); s += 1; } else
            if(!(*s & 16)) { c = ((*s & 0xF)<<12)|((*(s+1) & 0x3F)<<6)|(*(s+2) & 0x3F); s += 2; } else
            if(!(*s & 8)) { c = ((*s & 0x7)<<18)|((*(s+1) & 0x3F)<<12)|((*(s+2) & 0x3F)<<6)|(*(s+3) & 0x3F); s += 3; }
            else c = 0;
        } else c = *s;
        s++;
        // handle carrige return
        if(c == '\r') {
            x = 0; continue;
        } else
        // new line
        if(c == '\n') {
            x = 0; y += font->height; continue;
        }
        // find glyph, look up "c" in Character Table
        for(ptr = (unsigned char*)font + font->characters_offs, chr = 0, i = 0; i < 0x110000; i++) {
            if(ptr[0] == 0xFF) { i += 65535; ptr++; }
            else if((ptr[0] & 0xC0) == 0xC0) { j = (((ptr[0] & 0x3F) << 8) | ptr[1]); i += j; ptr += 2; }
            else if((ptr[0] & 0xC0) == 0x80) { j = (ptr[0] & 0x3F); i += j; ptr++; }
            else { if((unsigned int)i == c) { chr = ptr; break; } ptr += 6 + ptr[1] * (ptr[0] & 0x40 ? 6 : 5); }
        }
        if(!chr) continue;
        // uncompress and display fragments
        ptr = chr + 6; o = (unsigned long)lfb + y * pitch + x * 4;
        for(i = n = 0; i < chr[1]; i++, ptr += chr[0] & 0x40 ? 6 : 5) {
            if(ptr[0] == 255 && ptr[1] == 255) continue;
            frg = (unsigned char*)font + (chr[0] & 0x40 ? ((ptr[5] << 24) | (ptr[4] << 16) | (ptr[3] << 8) | ptr[2]) :
                ((ptr[4] << 16) | (ptr[3] << 8) | ptr[2]));
            if((frg[0] & 0xE0) != 0x80) continue;
            o += (int)(ptr[1] - n) * pitch; n = ptr[1];
            k = ((frg[0] & 0x1F) + 1) << 3; j = frg[1] + 1; frg += 2;
            for(m = 1; j; j--, n++, o += pitch)
                for(p = o, l = 0; l < k; l++, p += 4, m <<= 1) {
                    if(m > 0x80) { frg++; m = 1; }
                    if(*frg & m) *((unsigned int*)p) = 0xFFFFFF;
                }
        }
        // add advances
        x += chr[4]+1; y += chr[5];
    }
}