bool mapHandleEvent(SDL_Event *event) {
switch (event->type) {
case SDL_MOUSEMOTION:
// Drag the map with the right mouse button
if (event->motion.state & SDL_BUTTON_RMASK) {
map.offset.x += event->motion.x - map.dragPos.x;
map.offset.y += event->motion.y - map.dragPos.y;
SDL_WarpMouseInWindow(engine.window, map.dragPos.x, map.dragPos.y);
}
// Update block selection
map.selEnd = (Vector){
eucDiv(event->motion.x - map.offset.x, TILE_SIZE*map.zoom),
eucDiv(event->motion.y - map.offset.y, TILE_SIZE*map.zoom),
};
if (!(event->motion.state & SDL_BUTTON_LMASK)) {
map.selStart = map.selEnd;
}
break;
case SDL_MOUSEBUTTONDOWN:
if (event->button.button == SDL_BUTTON_RIGHT) {
// Capture cursor for map dragging
SDL_GetMouseState(&map.dragPos.x, &map.dragPos.y);
SDL_ShowCursor(0);
}
break;
case SDL_MOUSEBUTTONUP:
if (event->button.button == SDL_BUTTON_LEFT) {
// Holding in SHIFT deselects the block
SDL_Keymod mod = SDL_GetModState();
if (mod & KMOD_SHIFT) {
mapDeselect();
}
else {
mapSelect();
}
map.selStart = map.selEnd;
}
else if (event->button.button == SDL_BUTTON_RIGHT) {
// Uncapture cursor
SDL_ShowCursor(1);
}
break;
case SDL_KEYDOWN:
if (event->key.keysym.sym == SDLK_1) {
map.zoom = 1;
}
else if (event->key.keysym.sym == SDLK_2) {
map.zoom = 2;
}
}
return true;
}
void leastEntryAlgo(float A[][M][maxDegree+1], float P[][N][maxDegree+1], float Pinv[][N][maxDegree+1], float Q[][M][maxDegree+1], float Qinv[][M][maxDegree+1]) {
int n, m; // used in for loops over rows, columns respectively
int p; // used in for loops over polynomial array
int tempN, tempM, tempMin; //used to store temporary locations in A
int finished = 0; // bool to decide if while loop is over
int tempRowEntry, tempColEntry, tempMult, tempEntry;
int diag = 0;
float q[maxDegree+1];
// for finishedRows and finishedColumns,
// set entry i to -1 if row/col i is not finished, or
// set entry i to i if row/col i is finished
int finishedRows[N];
int finishedColumns[M];
//initializes finishedRows and finishedColumns
for(n = 0; n < N; ++n) {
finishedRows[n] = -1;
}
for(m = 0; m < M; ++m) {
finishedColumns[m] = -1;
}
// begin the least entry algorithm
while (finished == 0) {
// resets tempM and tempN to -1
tempM = -1;
tempN = -1;
// finds least non-zero entry, stores it in tempN, tempM
findLeastEntry(A, finishedRows, finishedColumns, &tempN, &tempM, &finished);
/* the loop should never break here; this if statement
is more or less a "just in case" used when developing */
if(finished == 1) { break; }
// resets tempRowEntry and tempColEntry to -1
tempRowEntry = -1;
tempColEntry = -1;
/* checks if we can do row operations. by convention established
(arbitrarily) in this program, we do row oeprations when we can */
if(contains(finishedColumns, M, tempM) == 0) {
// finds an entry for the least entry to reduce
for(n = 0; n < N; ++n) {
if(equalsZero(A[n][tempM]) == 0 && n != tempN) {
tempRowEntry = n;
break;
}
}
/* if there is no good entry to operate on, break the loop
in practice this would never happen, but convienient for dev. */
if (tempRowEntry == -1) { break; }
/* sets the vector q (in the sense of a = b*q + r)
so we can use it to do row operations */
eucDiv(A[tempRowEntry][tempM], A[tempN][tempM], q);
rowOperations2(A, P, Pinv, tempRowEntry, tempN, q);
}
// if we cannot do row operations, we do column operations
else {
for(m = 0; m < M; ++m) {
if(equalsZero(A[tempN][m]) == 0 && m != tempM) {
tempColEntry = m;
break;
}
}
if (tempColEntry == -1) { break; }
eucDiv(A[tempN][tempColEntry], A[tempN][tempM], q);
columnOperations2(A, Q, Qinv, tempColEntry, tempM, q);
}
// updates rows and colums that are finished
updateFinishedRows(A, finishedRows);
updateFinishedColumns(A, finishedColumns);
finished = done(finishedRows, finishedColumns, N, M);
}
// now we can compute the rank
rank = getRank(A);
/* perform type 3 operations to order the
non-zero elements onto the diagonals
*/
orderDiagonals(A, P, Pinv, Q, Qinv);
// make all polynomials monic
makeAllMonic(A, P, Pinv);
// computation trick: transpose Q and Pinv so they are correct
transposeM(Qinv);
transposeN(Pinv);
}
