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upiwin/buildutils/mkgfx.c
Amy Bowersox d1369964d7 The code has to be GPL'd, because the license of the BCM2835 library requires 
it.  Add the license document and the header on all source files.
2019-12-12 09:24:58 -07:00

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/*
* UPIWIN - Micro Pi Windowing Framework Kernel
* Copyright (C) 2019 Amy Bowersox/Erbosoft Metaverse Design Solutions
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*-------------------------------------------------------------------------
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <png.h>
typedef unsigned char uch;
typedef unsigned short ush;
typedef unsigned long ulg;
#ifndef png_jmpbuf
#define png_jmpbuf(png_ptr) ((png_ptr)->jmpbuf)
#endif
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
png_uint_32 width, height;
int bit_depth, color_type;
uch *image_data = NULL;
/* returns 0 on success, -1 on error */
int readpng_init(const char *fname, FILE *infile, ulg *pWidth, ulg *pHeight)
{
uch sig[8];
fread(sig, 1, 8, infile);
if (!png_check_sig(sig, 8))
{
fprintf(stderr, "%s: invalid PNG file signature\n", fname);
return -1;
}
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr)
{
fprintf(stderr, "%s: out of memory\n", fname);
return -1;
}
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
{
png_destroy_read_struct(&png_ptr, NULL, NULL);
fprintf(stderr, "%s: out of memory\n", fname);
return -1;
}
if (setjmp(png_jmpbuf(png_ptr)))
{
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
fprintf(stderr, "%s: bad header in PNG image\n", fname);
return -1;
}
png_init_io(png_ptr, infile);
png_set_sig_bytes(png_ptr, 8);
png_read_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, NULL, NULL, NULL);
*pWidth = width;
*pHeight = height;
return 0;
}
/* returns -1 on error, 0 otherwise (out vars not touched if we can't find background */
int readpng_get_bgcolor(const char *fname, uch *red, uch *green, uch *blue)
{
png_color_16p pBackground;
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
fprintf(stderr, "%s: unspecified error in background reading\n", fname);
return -1;
}
if (!png_get_valid(png_ptr, info_ptr, PNG_INFO_bKGD))
return 0;
png_get_bKGD(png_ptr, info_ptr, &pBackground);
if (bit_depth == 16)
{
*red = pBackground->red >> 8;
*green = pBackground->green >> 8;
*blue = pBackground->blue >> 8;
}
else if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
{
if (bit_depth == 1)
*red = *green = *blue = pBackground->gray ? 255 : 0;
else if (bit_depth == 2)
*red = *green = *blue = (255/3) * pBackground->gray;
else /* bit_depth == 4 */
*red = *green = *blue = (255/15) * pBackground->gray;
}
else
{
*red = (uch)pBackground->red;
*green = (uch)pBackground->green;
*blue = (uch)pBackground->blue;
}
return 0;
}
/* display_exponent == LUT_exponent * CRT_exponent */
uch *readpng_get_image(const char *fname, double display_exponent, int *pChannels, ulg *pRowbytes)
{
double gamma;
png_uint_32 i, rowbytes;
png_bytepp row_pointers = NULL;
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
fprintf(stderr, "%s: unspecified error in image data reading\n", fname);
return NULL;
}
if (color_type == PNG_COLOR_TYPE_PALETTE)
png_set_expand(png_ptr);
if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
png_set_expand(png_ptr);
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
png_set_expand(png_ptr);
if (bit_depth == 16)
png_set_strip_16(png_ptr);
if (color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png_ptr);
if (png_get_gAMA(png_ptr, info_ptr, &gamma))
png_set_gamma(png_ptr, display_exponent, gamma);
png_read_update_info(png_ptr, info_ptr);
*pRowbytes = rowbytes = png_get_rowbytes(png_ptr, info_ptr);
*pChannels = (int)png_get_channels(png_ptr, info_ptr);
if ((image_data = (uch *)malloc(rowbytes*height)) == NULL)
{
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
fprintf(stderr, "%s: could not allocate image buffer\n", fname);
return NULL;
}
if ((row_pointers = (png_bytepp)malloc(height*sizeof(png_bytep))) == NULL)
{
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
free(image_data);
image_data = NULL;
fprintf(stderr, "%s: could not allocate image row buffer\n", fname);
return NULL;
}
fprintf(stderr, "image %s: chans=%d rowbytes=%u height=%u\n", fname, *pChannels,
rowbytes, height);
for (i = 0; i < height; ++i)
row_pointers[i] = image_data + i * rowbytes;
png_read_image(png_ptr, row_pointers);
free(row_pointers);
row_pointers = NULL;
png_read_end(png_ptr, NULL);
return image_data;
}
void readpng_cleanup(int free_image_data)
{
if (free_image_data && image_data)
{
free(image_data);
image_data = NULL;
}
if (png_ptr && info_ptr)
{
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
png_ptr = NULL;
info_ptr = NULL;
}
}
int do_convert(const char *infilename, const char *outfilename)
{
ulg image_width, image_height, image_rowbytes, row, i;
FILE *fpin;
uch *image_data, *src;
uint16_t bred = 0, bgreen = 0, bblue = 0, buf = 0;
int image_channels, fdout;
uch bg_red=0, bg_green=0, bg_blue=0, br, bg, bb, ba;
double display_exponent = 2.2; /* a guesstimate */
if (!(fpin = fopen(infilename, "rb")))
{
fprintf(stderr, "%s: could not open file\n", infilename);
return -1;
}
if (readpng_init(infilename, fpin, &image_width, &image_height))
{
readpng_cleanup(1);
fclose(fpin);
return -1;
}
if (readpng_get_bgcolor(infilename, &bg_red, &bg_green, &bg_blue))
{
readpng_cleanup(1);
fclose(fpin);
return -1;
}
image_data = readpng_get_image(infilename, display_exponent, &image_channels, &image_rowbytes);
readpng_cleanup(0);
fclose(fpin);
if (!image_data)
return -1;
if ((fdout = creat(outfilename, S_IREAD|S_IWRITE)) < 0)
{
free(image_data);
fprintf(stderr, "%s: could not open file\n", outfilename);
return -1;
}
for (row = 0; row < image_height; ++row)
{
src = image_data + (row * image_rowbytes);
for (i = image_width; i > 0; --i)
{
if (image_channels == 3)
{
bred = *src++;
bgreen = *src++;
bblue = *src++;
}
else if (image_channels == 4)
{
br = *src++;
bg = *src++;
bb = *src++;
ba = *src++;
if (ba == 255)
{
bred = br;
bgreen = bg;
bblue = bb;
}
else if (ba == 0)
{
bred = bg_red;
bgreen = bg_green;
bblue = bg_blue;
}
else
{
png_composite(bred, br, ba, bg_red);
png_composite(bgreen, bg, ba, bg_green);
png_composite(bblue, bb, ba, bg_blue);
}
}
bred = (bred >> 3) & 0x1F;
bgreen = (bgreen >> 2) & 0x3F;
bblue = (bblue >> 3) & 0x1F;
buf = (bred << 11) | (bgreen << 5) | bblue;
if (write(fdout, &buf, sizeof(uint16_t)) < 0)
{
close(fdout);
free(image_data);
fprintf(stderr, "%s: error writing image data\n", outfilename);
return -1;
}
}
}
close(fdout);
free(image_data);
return 0;
}
int main(int argc, char *argv[])
{
if (argc < 3)
{
fprintf(stderr, "usage: mksplash inputfile outputfile\n");
return EXIT_FAILURE;
}
if (do_convert(argv[1], argv[2]))
return EXIT_FAILURE;
return EXIT_SUCCESS;
}
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