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Looks like my projects default to C11 (with GNU extensions) these daysstephen_usher wrote: 18 Oct 2023 19:41 Erm, what standard of C is that? GCC 2.95.2 won't compile it as there are variable definitions interspersed with the code. That's not valid for ANSI C (C89?).
I was using gcc 4.6.4 which doesn't allow declarations in loops, but does within code blocks.SpacedCowboy wrote: 18 Oct 2023 19:55 That's fair :)
Badwolf reposted the code above with changes that seemed to fix (actually, I'm going to use "fix") the issues, reading through it earlier. I noticed he'd declared loop variables outside the for() statement etc.
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/*/
// main.c
// aspiral
//
// Created by ThrudTheBarbarian on 10/17/23.
/*/
#include <unistd.h>
#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include "gem.h"
#ifdef QGEM
#include "gemio.h"
#include "gemmsg.h"
#include "rscfile.h"
#include "vdi.h"
#endif
/*****************************************************************************\
|* Forward declarations
\*****************************************************************************/
void plotArchimedesSpiral(int handle, int offX, int offY, int transparent);
/*****************************************************************************\
|* Archimedes spiral as a line-drawing demo
\*****************************************************************************/
int main(int argc, const char * argv[])
{
int16_t workIn[16];
int16_t workOut[128];
int16_t handle;
for (int i=0; i<16; i++)
workIn[i] = -1;
workIn[0] = 1;
workIn[2] = 2;
/*************************************************************************\
|* Connect to the display, clear it, and ensure we're in graphics mode
\*************************************************************************/
v_opnvwk(workIn, &handle, workOut);
v_clrwk();
vq_exit_cur(handle);
plotArchimedesSpiral(handle, 0,0, 1);
plotArchimedesSpiral(handle, 320,0, 0);
}
/*****************************************************************************\
|* Plot algorithm
\*****************************************************************************/
void plotArchimedesSpiral(int handle, int offX, int offY, int transparent)
{
struct timeval stt, end, dt;
/*************************************************************************\
|* Set up the parameters
\*************************************************************************/
const int kSize = 144;
int xp = kSize;
float xr = 4.71238905f;
float xf = xr / xp;
float zt, zs, xl, xt, yy, x1, y1;
int zi, xi;
int16_t pxy[4];
int16_t black[3] = {0,0,0};
char buf[128];
gettimeofday(&stt, NULL);
vsl_color(handle, 0);
/*************************************************************************\
|* Draw the plot
\*************************************************************************/
for (zi = -64; zi < 64; zi++)
{
zt = zi * 2.25f;
zs = zt * zt;
xl = (int)(sqrtf(kSize * kSize - zs) + 0.5f);
for (xi = -xl; xi<xl; xi++)
{
xt = sqrt(xi*xi + zs) * xf;
yy = (sin(xt) + sin(xt*3) * 0.4) * 56;
x1 = offX + xi + zi + 160;
y1 = offY + 90 - yy + zi;
vs_pixrgb(handle, x1, y1, black);
if (transparent == 0)
{
pxy[0] = (int16_t)x1
pxy[1] = (int16_t)(y1+1)
pxy[2] = (int16_t)x1;
pxy[3] = 191};
v_pline(handle, 2, pxy);
}
}
}
/*************************************************************************\
|* Show how long it took
\*************************************************************************/
gettimeofday(&end, NULL);
timersub(&end, &stt, &dt);
sprintf(buf, "Time taken: %d.%06d secs", (int)dt.tv_sec, (int)dt.tv_usec);
vst_alignment(handle, ALGN_CENTER, ALGN_BASELINE, NULL, NULL);
v_justified(handle, offX, offY + 220, 320, 0,0, buf);
}
stephen_usher wrote: 18 Oct 2023 22:38 OK, not tried it on a real machine yet but this should hopefully be C89 compliant:
So I tried to take what you did and what Stephen did, set my compiler to be C89 and the version checked in now compiles for me. I'm not sure just how C89-like clang is, but it did throw up some warnings which I fixed. I also addedBadwolf wrote: 18 Oct 2023 20:16 I was using gcc 4.6.4 which doesn't allow declarations in loops, but does within code blocks.
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/*****************************************************************************\
|* Define a constant so we know it's our version of GEM
\*****************************************************************************/
#ifndef QGEM
# define QGEM 1
#endif
Yeah, it's just the original algorithm from Analog - it overdraws in white from the next line down to the bottom of the screen, which has the effect of "hidden line removal".Badwolf wrote: 18 Oct 2023 20:16 I hadn't quite twigged what you were doing with the transparent option, so I ended up commenting that out and not implementing the lines to the bottom. Easy to put back.
Whoops - thanks, good catch - fixed. I also removed the hackery that allowed a direct pixel-set with an RGB value (since I always have a 1080p @ 32-bit screen, being able to plot a pixel without a bunch of setup was nice, and avoiding several round-trips because of each function call was nice too :)) - anyway, the new figures I get are:Badwolf wrote: 18 Oct 2023 20:16 PS. I think the parameter order in your implementation of vt_justified was wrong, but I ended up going with gtext anyway.
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int16_t black[3] = { 0, 0, 0 };