void setCurve(uint8_t c, const pm_int8_t ar[])
{
int8_t * cv = curveAddress(c);
for (uint8_t i=0; i<5; i++) {
cv[i] = pgm_read_byte(&ar[i]);
}
}
CurveInfo curveInfo(uint8_t idx)
{
CurveInfo result;
result.crv = curveAddress(idx);
int8_t *next = curveAddress(idx+1);
uint8_t size = next - result.crv;
if ((size & 1) == 0) {
result.points = (size / 2) + 1;
result.custom = true;
}
else {
result.points = size;
result.custom = false;
}
return result;
}
int intpol(int x, uint8_t idx) // -100, -75, -50, -25, 0 ,25 ,50, 75, 100
{
#if defined(XCURVES)
CurveInfo &crv = g_model.curves[idx];
int8_t *points = curveAddress(idx);
uint8_t count = crv.points+5;
bool custom = (crv.type == CURVE_TYPE_CUSTOM);
#else
CurveInfo crv = curveInfo(idx);
int8_t *points = crv.crv;
uint8_t count = crv.points;
bool custom = crv.custom;
#endif
int16_t erg = 0;
x += RESXu;
if (x <= 0) {
erg = (int16_t)points[0] * (RESX/4);
}
else if (x >= (RESX*2)) {
erg = (int16_t)points[count-1] * (RESX/4);
}
else {
uint16_t a=0, b=0;
uint8_t i;
if (custom) {
for (i=0; i<count-1; i++) {
a = b;
b = (i==count-2 ? 2*RESX : RESX + calc100toRESX(points[count+i]));
if ((uint16_t)x<=b) break;
}
}
else {
uint16_t d = (RESX * 2) / (count-1);
i = (uint16_t)x / d;
a = i * d;
b = a + d;
}
erg = (int16_t)points[i]*(RESX/4) + ((int32_t)(x-a) * (points[i+1]-points[i]) * (RESX/4)) / ((b-a));
}
return erg / 25; // 100*D5/RESX;
}
/* The following is a hermite cubic spline.
The basis functions can be found here:
http://en.wikipedia.org/wiki/Cubic_Hermite_spline
The tangents are computed via the 'cubic monotone' rules (allowing for local-maxima)
*/
int16_t hermite_spline(int16_t x, uint8_t idx)
{
CurveInfo &crv = g_model.curves[idx];
int8_t *points = curveAddress(idx);
uint8_t count = crv.points+5;
bool custom = (crv.type == CURVE_TYPE_CUSTOM);
if (x < -RESX)
x = -RESX;
else if (x > RESX)
x = RESX;
for (int i=0; i<count-1; i++) {
s32 p0x, p3x;
if (custom) {
p0x = (i>0 ? calc100toRESX(points[count+i-1]) : -RESX);
p3x = (i<count-2 ? calc100toRESX(points[count+i]) : RESX);
}
else {
p0x = -RESX + (i*2*RESX)/(count-1);
p3x = -RESX + ((i+1)*2*RESX)/(count-1);
}
if (x >= p0x && x <= p3x) {
s32 p0y = calc100toRESX(points[i]);
s32 p3y = calc100toRESX(points[i+1]);
s32 m0 = compute_tangent(&crv, points, i);
s32 m3 = compute_tangent(&crv, points, i+1);
s32 y;
s32 h = p3x - p0x;
s32 t = (h > 0 ? (MMULT * (x - p0x)) / h : 0);
s32 t2 = t * t / MMULT;
s32 t3 = t2 * t / MMULT;
s32 h00 = 2*t3 - 3*t2 + MMULT;
s32 h10 = t3 - 2*t2 + t;
s32 h01 = -2*t3 + 3*t2;
s32 h11 = t3 - t2;
y = p0y * h00 + h * (m0 * h10 / MMULT) + p3y * h01 + h * (m3 * h11 / MMULT);
y /= MMULT;
return y;
}
}
return 0;
}
static int luaModelGetCurve(lua_State *L)
{
unsigned int idx = luaL_checkunsigned(L, 1);
if (idx < MAX_CURVES) {
CurveInfo & curveInfo = g_model.curves[idx];
lua_newtable(L);
lua_pushtablezstring(L, "name", g_model.curveNames[idx]);
lua_pushtableinteger(L, "type", curveInfo.type);
lua_pushtableboolean(L, "smooth", curveInfo.smooth);
lua_pushtableinteger(L, "points", curveInfo.points+5);
lua_pushstring(L, "y");
lua_newtable(L);
int8_t * point = curveAddress(idx);
for (int i=0; i<curveInfo.points+5; i++) {
lua_pushinteger(L, i);
lua_pushinteger(L, *point++);
lua_settable(L, -3);
}
lua_settable(L, -3);
if (curveInfo.type == CURVE_TYPE_CUSTOM) {
lua_pushstring(L, "x");
lua_newtable(L);
lua_pushinteger(L, 0);
lua_pushinteger(L, 0);
lua_settable(L, -3);
for (int i=0; i<curveInfo.points+3; i++) {
lua_pushinteger(L, i+1);
lua_pushinteger(L, *point++);
lua_settable(L, -3);
}
lua_pushinteger(L, curveInfo.points+4);
lua_pushinteger(L, 100);
lua_settable(L, -3);
lua_settable(L, -3);
}
}
else {
lua_pushnil(L);
}
return 1;
}
