Skip to content

Commit

Permalink
Forward differencing test
Browse files Browse the repository at this point in the history
  • Loading branch information
@dpt
dpt committed Feb 11, 2024
1 parent 745e6c4 commit 2bcf232
Showing 1 changed file with 127 additions and 57 deletions.
184 changes: 127 additions & 57 deletions libraries/framebuf/curve/test/curve-test.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -177,12 +177,12 @@ static void stop_sdl(sdlstate_t *state)
/* ----------------------------------------------------------------------- */

#define BLOBSZ (8)
#define NSETS (5)
#define MAXCONTROLPTS (2 + 3 + 4 + 5 + 6)
#define NSETS (6)
#define MAXCONTROLPTS (2 + 3 + 4 + 5 + 6 + 4)
#define MINSEGMENTS (1)
#define MAXSEGMENTS (128)
#define BORDER (64)
#define UNIT (96)
#define BORDER (32)
#define UNIT (32)

/* ----------------------------------------------------------------------- */

Expand All @@ -194,18 +194,21 @@ static const struct
Quadratic,
Cubic,
Quartic,
Quintic
Quintic,
FwdDiffCubic
}
kind;
int npoints;
int offset;
}
curves[] =
{
{ Linear, 0 },
{ Quadratic, 0 + 2 },
{ Cubic, 0 + 2 + 3 },
{ Quartic, 0 + 2 + 3 + 4 },
{ Quintic, 0 + 2 + 3 + 4 + 5 },
{ Linear, 2, 0 },
{ Quadratic, 3, 0 + 2 },
{ Cubic, 4, 0 + 2 + 3 },
{ Quartic, 5, 0 + 2 + 3 + 4 },
{ Quintic, 6, 0 + 2 + 3 + 4 + 5 },
{ FwdDiffCubic, 4, 0 + 2 + 3 + 4 + 5 + 6 }
};

/* ----------------------------------------------------------------------- */
Expand Down Expand Up @@ -259,6 +262,62 @@ static point_t jitter_off(point_t p)

/* ----------------------------------------------------------------------- */

void calcBezier(point_t p1, point_t p2, point_t p3, point_t p4,
int nsteps, point_t *points)
{
float cx = 3 * (p2.x - p1.x);
float cy = 3 * (p2.y - p1.y);

float bx = 3 * (p3.x - p2.x) - cx;
float by = 3 * (p3.y - p2.y) - cy;

float ax = p4.x - p1.x - cx - bx;
float ay = p4.y - p1.y - cy - by;

float h = 1.0f / nsteps;
float hh = h * h;
float hhh = hh * h;

// first difference
float d1x = ax * hhh + bx * hh + cx * h;
float d1y = ay * hhh + by * hh + cy * h;

// second
float d2x = 6 * ax * hhh + 2 * bx * hh;
float d2y = 6 * ay * hhh + 2 * by * hh;

// third
float d3x = 6 * ax * hhh;
float d3y = 6 * ay * hhh;

float currentX = p1.x;
float currentY = p1.y;

points[0].x = currentX;
points[0].y = currentY;

// skip first and last points
for (int i = 1; i < nsteps; i++)
{
currentX += d1x;
currentY += d1y;

d1x += d2x;
d1y += d2y;

d2x += d3x;
d2y += d3y;

points[i].x = currentX;
points[i].y = currentY;
}

points[nsteps].x = p4.x;
points[nsteps].y = p4.y;
}

/* ----------------------------------------------------------------------- */

static void setup_all_curves(curveteststate_t *state)
{
int cpi;
Expand All @@ -269,11 +328,11 @@ static void setup_all_curves(curveteststate_t *state)
int lefthand;
int i;

cpi = 0; /* control point index */
y = 0;
npoints = 2;
cpi = 0; /* control point index */
y = BORDER;
for (set = 0; set < NSETS; set++)
{
npoints = curves[set].npoints;
width = (npoints - 1) * UNIT;
lefthand = (state->scr_width - width) / 2;

Expand All @@ -284,8 +343,7 @@ static void setup_all_curves(curveteststate_t *state)
cpi++;
}

y += state->section_height + BLOBSZ;
npoints++;
y += state->section_height;
}
}

Expand All @@ -298,10 +356,11 @@ static void draw_all_control_points(curveteststate_t *state)
box_t b;
colour_t colour;

cpi = 0;
npoints = 2;
cpi = 0;
for (set = 0; set < NSETS; set++)
{
npoints = curves[set].npoints;

for (i = 0; i < npoints; i++)
{
b.x0 = state->control_points[cpi].x - BLOBSZ / 2;
Expand All @@ -317,7 +376,6 @@ static void draw_all_control_points(curveteststate_t *state)

cpi++;
}
npoints++;
}
}

Expand Down Expand Up @@ -367,51 +425,63 @@ static void calc_all_curves(curveteststate_t *state)
{
o = curves[set].offset;

for (i = 0; i < state->nsegments + 1; i++)
if (curves[set].kind == FwdDiffCubic)
{
t = 65536 * i / state->nsegments;

switch (curves[set].kind)
calcBezier(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
state->jitterfn(state->control_points[o + 2]),
state->jitterfn(state->control_points[o + 3]),
state->nsegments,
&state->draw_points[0]);
}
else
{
for (i = 0; i < state->nsegments + 1; i++)
{
case Linear:
state->draw_points[i] = curve_point_on_line(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
t);
break;

case Quadratic:
state->draw_points[i] = curve_bezier_point_on_quad(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
state->jitterfn(state->control_points[o + 2]),
t);
break;

case Cubic:
state->draw_points[i] = curve_bezier_point_on_cubic(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
state->jitterfn(state->control_points[o + 2]),
state->jitterfn(state->control_points[o + 3]),
t);
break;

case Quartic:
state->draw_points[i] = curve_bezier_point_on_quartic(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
state->jitterfn(state->control_points[o + 2]),
state->jitterfn(state->control_points[o + 3]),
state->jitterfn(state->control_points[o + 4]),
t);
break;
t = 65536 * i / state->nsegments;

switch (curves[set].kind)
{
case Linear:
state->draw_points[i] = curve_point_on_line(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
t);
break;

case Quintic:
state->draw_points[i] = curve_bezier_point_on_quintic(state->jitterfn(state->control_points[o + 0]),
case Quadratic:
state->draw_points[i] = curve_bezier_point_on_quad(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
state->jitterfn(state->control_points[o + 2]),
t);
break;

case Cubic:
state->draw_points[i] = curve_bezier_point_on_cubic(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
state->jitterfn(state->control_points[o + 2]),
state->jitterfn(state->control_points[o + 3]),
state->jitterfn(state->control_points[o + 4]),
state->jitterfn(state->control_points[o + 5]),
t);
break;
break;

case Quartic:
state->draw_points[i] = curve_bezier_point_on_quartic(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
state->jitterfn(state->control_points[o + 2]),
state->jitterfn(state->control_points[o + 3]),
state->jitterfn(state->control_points[o + 4]),
t);
break;

case Quintic:
state->draw_points[i] = curve_bezier_point_on_quintic(state->jitterfn(state->control_points[o + 0]),
state->jitterfn(state->control_points[o + 1]),
state->jitterfn(state->control_points[o + 2]),
state->jitterfn(state->control_points[o + 3]),
state->jitterfn(state->control_points[o + 4]),
state->jitterfn(state->control_points[o + 5]),
t);
break;
}
}
}

Expand Down Expand Up @@ -474,7 +544,7 @@ static result_t curve_interactive_test(curveteststate_t *state)
box_reset(&state->overalldirty);
state->jitterfn = &jitter_off;

state->section_height = (state->scr_height - (NSETS - 1) * BLOBSZ) / NSETS; /* divide screen into chunks */
state->section_height = (state->scr_height - 2 * BORDER) / NSETS; /* divide screen into chunks */

setup_all_curves(state);

Expand Down

0 comments on commit 2bcf232

Please sign in to comment.