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#include <string.h>
#include "pam.h"
#include "shhopt.h"
#include "mallocvar.h"
struct cmdlineInfo {
tuple colorTopLeft;
tuple colorTopRight;
tuple colorBottomLeft;
tuple colorBottomRight;
unsigned depth;
unsigned int cols;
unsigned int rows;
unsigned int maxval;
};
static void
parseCommandLine(int argc, char **argv,
struct cmdlineInfo * const cmdlineP) {
/*----------------------------------------------------------------------------
Convert program invocation arguments (argc,argv) into a format the
program can use easily, struct cmdlineInfo. Validate arguments along
the way and exit program with message if invalid.
Note that some string information we return as *cmdlineP is in the storage
argv[] points to.
-----------------------------------------------------------------------------*/
optEntry * option_def;
/* Instructions to OptParseOptions3 on how to parse our options.
*/
optStruct3 opt;
unsigned int maxvalSpec;
unsigned int option_def_index;
MALLOCARRAY_NOFAIL(option_def, 100);
option_def_index = 0;
OPTENT3(0, "maxval", OPT_UINT, &cmdlineP->maxval, &maxvalSpec, 0);
opt.opt_table = option_def;
opt.short_allowed = FALSE; /* We have no short (old-fashioned) options */
opt.allowNegNum = FALSE; /* We have no parms that are negative numbers */
optParseOptions3(&argc, argv, opt, sizeof(opt), 0);
/* Uses and sets argc, argv, and some of *cmdlineP and others. */
if (!maxvalSpec)
cmdlineP->maxval = 255;
else {
if (cmdlineP->maxval > PAM_OVERALL_MAXVAL)
pm_error("The value you specified for -maxval (%u) is too big. "
"Max allowed is %u", cmdlineP->maxval,
PAM_OVERALL_MAXVAL);
if (cmdlineP->maxval < 1)
pm_error("You cannot specify 0 for -maxval");
}
if (argc-1 != 6) {
pm_error("Need 6 arguments: colorTopLeft, colorTopRight, "
"colorBottomLeft, colorBottomRight, width, height");
} else {
cmdlineP->colorTopLeft = pnm_parsecolor(argv[1], cmdlineP->maxval);
cmdlineP->colorTopRight = pnm_parsecolor(argv[2], cmdlineP->maxval);
cmdlineP->colorBottomLeft = pnm_parsecolor(argv[3], cmdlineP->maxval);
cmdlineP->colorBottomRight = pnm_parsecolor(argv[4], cmdlineP->maxval);
cmdlineP->cols = atoi(argv[5]);
cmdlineP->rows = atoi(argv[6]);
if (cmdlineP->cols <= 0)
pm_error("width argument must be a positive number. You "
"specified '%s'", argv[5]);
if (cmdlineP->rows <= 0)
pm_error("height argument must be a positive number. You "
"specified '%s'", argv[6]);
}
}
static void
freeCmdline(struct cmdlineInfo const cmdline) {
pnm_freepamtuple(cmdline.colorTopLeft);
pnm_freepamtuple(cmdline.colorTopRight);
pnm_freepamtuple(cmdline.colorBottomLeft);
pnm_freepamtuple(cmdline.colorBottomRight);
}
static void
interpolate(struct pam * const pamP,
tuple * const tuplerow,
tuple const first,
tuple const last) {
unsigned int plane;
for (plane = 0; plane < pamP->depth; ++plane) {
int const spread = last[plane] - first[plane];
int col;
if (INT_MAX / pamP->width < abs(spread))
pm_error("Arithmetic overflow. You must reduce the width of "
"the image (now %u) or the range of color values "
"(%u in plane %u) so that their "
"product is less than %d",
pamP->width, abs(spread), plane, INT_MAX);
for (col = 0; col < pamP->width; ++col)
tuplerow[col][plane] =
first[plane] + (spread * col / (int)pamP->width);
}
}
static int
isgray(struct pam * const pamP,
tuple const color) {
return (pamP->depth == 1)
|| ((pamP->depth == 3)
&& (color[PAM_RED_PLANE] == color[PAM_GRN_PLANE])
&& (color[PAM_RED_PLANE] == color[PAM_BLU_PLANE]));
}
static tuple *
createEdge(const struct pam * const pamP,
tuple const topColor,
tuple const bottomColor) {
/*----------------------------------------------------------------------------
Create a left or right edge, interpolating from top to bottom.
-----------------------------------------------------------------------------*/
struct pam interpPam;
tuple * tupleRow;
interpPam = *pamP; /* initial value */
interpPam.width = pamP->height;
interpPam.height = 1;
tupleRow = pnm_allocpamrow(&interpPam);
interpolate(&interpPam, tupleRow, topColor, bottomColor);
return tupleRow;
}
int
main(int argc, char *argv[]) {
struct cmdlineInfo cmdline;
struct pam pam;
tuple * tupleRow;
tuple * leftEdge;
tuple * rightEdge;
unsigned int row;
pnm_init(&argc, argv);
parseCommandLine(argc, argv, &cmdline);
pam.size = sizeof pam;
pam.len = PAM_STRUCT_SIZE(tuple_type);
pam.file = stdout;
pam.plainformat = 0;
pam.width = cmdline.cols;
pam.height = cmdline.rows;
pam.maxval = cmdline.maxval;
pam.bytes_per_sample = pnm_bytespersample(pam.maxval);
pam.format = PAM_FORMAT;
if (isgray(&pam, cmdline.colorTopLeft)
&& isgray(&pam, cmdline.colorTopRight)
&& isgray(&pam, cmdline.colorBottomLeft)
&& isgray(&pam, cmdline.colorBottomRight)) {
pam.depth = 1;
strcpy(pam.tuple_type, PAM_PGM_TUPLETYPE);
} else {
pam.depth = 3;
strcpy(pam.tuple_type, PAM_PPM_TUPLETYPE);
}
pnm_writepaminit(&pam);
tupleRow = pnm_allocpamrow(&pam);
leftEdge = createEdge(&pam,
cmdline.colorTopLeft, cmdline.colorBottomLeft);
rightEdge = createEdge(&pam,
cmdline.colorTopRight, cmdline.colorBottomRight);
/* interpolate each row between the left edge and the right edge */
for (row = 0; row < pam.height; ++row) {
interpolate(&pam, tupleRow, leftEdge[row], rightEdge[row]);
pnm_writepamrow(&pam, tupleRow);
}
pm_close(stdout);
pnm_freepamrow(rightEdge);
pnm_freepamrow(leftEdge);
pnm_freepamrow(tupleRow);
freeCmdline(cmdline);
return 0;
}
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