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WIP 2-point perspective

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Works okay assuming vanishing points form a horizontal line,
but that won't always be the case.
This commit is contained in:
Bill Kendrick 2023-12-21 00:32:03 -08:00
parent f68909c70e
commit a72e5b9b42
1 changed files with 50 additions and 4 deletions
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54
magic/src/n_pt_persp.c
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@ -5,7 +5,7 @@
by Bill Kendrick <bill@newbreedsoftware.com>
December 12, 2023 - December 17, 2023
December 12, 2023 - December 21, 2023
*/
@ -181,7 +181,7 @@ int n_pt_persp_init(magic_api * api, Uint32 disabled_features ATTRIBUTE_UNUSED)
int n_pt_persp_get_tool_count(magic_api * api ATTRIBUTE_UNUSED)
{
return 2; // FIXME
return 4; // FIXME
//return (NUM_TOOLS);
}
@ -401,8 +401,54 @@ void n_pt_persp_work(magic_api * api, int which,
} else if (which == TOOL_2PT_DRAW) {
/* 2-point perspective */
/* FIXME */
return;
x1 = line_start_x;
y1 = line_start_y;
if (abs(line_start_x - x) <= SNAP) {
/* Vertical */
x2 = x1;
y2 = y;
} else if (abs(line_start_y - y) <= SNAP) {
/* Horizontal */
x2 = x;
y2 = y1;
} else {
int ok, i;
/* Diagonal */
ok = 0;
for (i = 0; i < 2 && ok == 0; i++) {
slope = ((float) y1 - (float) a2_pt_y[i]) / ((float) x1 - (float) a2_pt_x[i]);
x2 = x;
y2 = line_start_y + (slope * (x - line_start_x));
/* Don't go past our cursor's Y */
if ((y < line_start_y && y2 < y) ||
(y > line_start_y && y2 > y)) {
if (slope != 0.0) {
y2 = y;
x2 = ((y - line_start_y) / slope) + line_start_x;
}
}
/* Wrong side? Use the point 2 */
slope2 = ((float) line_start_y - (float) y) / ((float) line_start_x - (float) x);
if ((slope2 > 0.00 && slope < 0.00) ||
(slope2 < 0.00 && slope > 0.00)) {
ok = 0;
if (i == 1) {
/* Worst case, snap to horizontal */
x2 = x;
y2 = y1;
}
} else {
ok = 1;
}
}
}
} else if (which == TOOL_3PT_DRAW) {
/* 3-point perspective */