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mirror of https://github.com/pdf2htmlEX/pdf2htmlEX.git synced 2024-12-22 13:00:08 +00:00

rewrite the line merging code, to ease future optimizations

This commit is contained in:
Lu Wang 2013-04-05 18:25:46 +08:00
parent cf636fd41f
commit 111edcec47

View File

@ -295,33 +295,33 @@ void HTMLRenderer::check_state_change(GfxState * state)
bool merged = false;
double dx = 0;
double dy = 0;
if(tm_equal(old_tm, cur_text_tm, 4))
{
double lhs1 = cur_text_tm[4] - old_tm[4] - old_tm[2] * (draw_ty - cur_ty) - old_tm[0] * (draw_tx - cur_tx);
double lhs2 = cur_text_tm[5] - old_tm[5] - old_tm[3] * (draw_ty - cur_ty) - old_tm[1] * (draw_tx - cur_tx);
double lhs1 = cur_text_tm[4] - old_tm[4] - old_tm[0] * (draw_tx - cur_tx) - old_tm[2] * (draw_ty - cur_ty);
double lhs2 = cur_text_tm[5] - old_tm[5] - old_tm[1] * (draw_tx - cur_tx) - old_tm[3] * (draw_ty - cur_ty);
if(equal(old_tm[0] * lhs2, old_tm[1] * lhs1))
/*
* Now the equation system becomes
*
* lhs1 = OldTM[0] * dx + OldTM[2] * dy
* lhs2 = OldTM[1] * dx + OldTM[3] * dy
*/
double det = old_tm[0] * old_tm[3] - old_tm[1] * old_tm[2];
if(!equal(det, 0))
{
if(!equal(old_tm[0], 0))
double inverted[4];
inverted[0] = old_tm[3] / det;
inverted[1] = -old_tm[1] / det;
inverted[2] = -old_tm[2] / det;
inverted[3] = old_tm[0] / det;
dx = inverted[0] * lhs1 + inverted[2] * lhs2;
dy = inverted[1] * lhs1 + inverted[3] * lhs2;
if(equal(dy, 0))
{
dx = lhs1 / old_tm[0];
merged = true;
}
else if (!equal(old_tm[1], 0))
{
dx = lhs2 / old_tm[1];
merged = true;
}
else
{
if((equal(lhs1,0)) && (equal(lhs2,0)))
{
// free
dx = 0;
merged = true;
}
// else fail
}
}
//else no solution
}