fabs/rotate-me-fast
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Factorize the computation of the source point.

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This commit is contained in:
Fabien Freling 2014-07-02 22:38:57 +02:00
parent 7e33e85909
commit e86dbe0f36
1 changed files with 9 additions and 16 deletions
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25
rotation.cpp
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@ -761,16 +761,10 @@ void rotate_pixel(TiledImage<W, H> const& src, TiledImage<W, H>& rotated,
// special case if we can directly map the src to the dest // special case if we can directly map the src to the dest
if (x_delta == 0 && y_delta == 0) if (x_delta == 0 && y_delta == 0)
{ {
// cout << "we can directly map, w00t" << endl;
uint8_t* rot_tile = rotated.tiles[rot_tile_index]; uint8_t* rot_tile = rotated.tiles[rot_tile_index];
memcpy(&rot_tile[rot_index], src_index_1, 3 * sizeof (uint8_t)); memcpy(&rot_tile[rot_index], src_index_1, 3 * sizeof (uint8_t));
return; return;
} }
// cout << "src rotated point: " << src_rotated_point << endl;
// cout << "src rotated point y: " << src_rotated_point.y << endl;
// cout << "src rotated point y int: " << (int) src_rotated_point.y << endl;
// cout << "x delta = " << x_delta << endl;
// cout << "y delta = " << y_delta << endl;
uint8_t const* src_index_2 = src.access_pixel((int) src_rotated_point.x + 1, (int) src_rotated_point.y); uint8_t const* src_index_2 = src.access_pixel((int) src_rotated_point.x + 1, (int) src_rotated_point.y);
uint8_t const* src_index_3 = src.access_pixel((int) src_rotated_point.x, (int) src_rotated_point.y + 1); uint8_t const* src_index_3 = src.access_pixel((int) src_rotated_point.x, (int) src_rotated_point.y + 1);
@ -842,18 +836,14 @@ TiledImage<W, H> rotate(TiledImage<W, H> const& src, double angle)
for (unsigned int j = 0; j < H; ++j) for (unsigned int j = 0; j < H; ++j)
{ {
int const y_index = y * H + j; int const y_index = y * H + j;
int x_index = x * W;
DPoint src_rotated_point(rot_origin_in_src.x + x_index * src_delta_x.x + y_index * src_delta_y.x,
rot_origin_in_src.y + x_index * src_delta_x.y + y_index * src_delta_y.y);
for (unsigned int i = 0; i < W; ++i) for (unsigned int i = 0; i < W; ++i, ++x_index)
{ {
// cout << "rotated: tile[" << x << ", " << y << "] point(" << i << ", " << j << ")" << endl;
unsigned int const rot_index = (j * W + i) * 3; unsigned int const rot_index = (j * W + i) * 3;
int const x_index = x * W + i;
Point const rot_point(x_index, y_index); Point const rot_point(x_index, y_index);
DPoint src_rotated_point(rot_origin_in_src.x + x_index * src_delta_x.x + y_index * src_delta_y.x,
rot_origin_in_src.y + x_index * src_delta_x.y + y_index * src_delta_y.y);
// cout << "rotated tile index: " << rot_tile_index << endl;
// cout << "src point: " << src_rotated_point << endl;
if (src_rotated_point.x < 0 || src_rotated_point.x > src.width if (src_rotated_point.x < 0 || src_rotated_point.x > src.width
|| src_rotated_point.y < 0 || src_rotated_point.y > src.height) || src_rotated_point.y < 0 || src_rotated_point.y > src.height)
@ -863,6 +853,9 @@ TiledImage<W, H> rotate(TiledImage<W, H> const& src, double angle)
src_rotated_point, src_rotated_point,
rot_tile_index, rot_index); rot_tile_index, rot_index);
src_rotated_point.x += src_delta_x.x;
src_rotated_point.y += src_delta_x.y;
} }
} }
} }
@ -1036,9 +1029,9 @@ int main(int argc, char* argv[])
} }
Image img(argv[1]); Image img(argv[1]);
TiledImage<16, 16> tiled_img(argv[1]); TiledImage<32, 32> tiled_img(argv[1]);
for (double rotation = 0; rotation < 360; rotation += 450) for (double rotation = 0; rotation < 360; rotation += 45)
{ {
// No tile // No tile
auto const before = chrono::high_resolution_clock::now(); auto const before = chrono::high_resolution_clock::now();