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Fix "Cairo: Scaled images draw with wrong size" (#537)

This commit is contained in:
ManoloFLTK 2022-11-17 07:14:20 +01:00
parent 2dae18da09
commit 167a3268c9
1 changed files with 6 additions and 14 deletions
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20
src/drivers/Cairo/Fl_Cairo_Graphics_Driver.cxx
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@ -761,26 +761,18 @@ void Fl_Cairo_Graphics_Driver::draw_cached_pattern_(Fl_Image *img, cairo_pattern
int Hs = Fl_Scalable_Graphics_Driver::floor(Y - cy + img->h(), s) - Ys;
if (Ws == 0 || Hs == 0) return;
cairo_save(cairo_);
if (cx || cy || W < img->w() || H < img->h()) { // clip when necessary
cairo_rectangle(cairo_, X-0.5, Y-0.5, W+1, H+1);
cairo_clip(cairo_);
}
cairo_rectangle(cairo_, X - 0.5, Y - 0.5, W + 0.5, H + 0.5);
cairo_clip(cairo_);
// remove any scaling and the current "0.5" translation useful for lines but bad for images
matrix.xx = matrix.yy = 1;
matrix.x0 -= 0.5 * s; matrix.y0 -= 0.5 * s;
cairo_set_matrix(cairo_, &matrix);
if (img->d() >= 1) cairo_set_source(cairo_, pat);
int offset = 0;
if (Ws >= img->data_w()*1.09 || Hs >= img->data_h()*1.09) {
// When enlarging while drawing, 1 pixel around target area seems unpainted,
// so we increase a bit the target area and move it int(s) pixels to left and top.
Ws = (img->w()+2)*s, Hs = (img->h()+2)*s;
offset = int(s);
}
//fprintf(stderr,"WHs=%dx%d dataWH=%dx%d s=%.1f offset=%d\n",Ws,Hs,img->data_w(),img->data_h(),s,offset);
cairo_pattern_set_filter(pat, Fl_RGB_Image::scaling_algorithm() == FL_RGB_SCALING_BILINEAR ?
CAIRO_FILTER_GOOD : CAIRO_FILTER_FAST);
cairo_pattern_set_extend(pat, CAIRO_EXTEND_PAD);
cairo_matrix_init_scale(&matrix, double(img->data_w())/Ws, double(img->data_h())/Hs);
cairo_matrix_translate(&matrix, -Xs + offset, -Ys + offset);
cairo_matrix_translate(&matrix, -Xs , -Ys );
cairo_pattern_set_matrix(pat, &matrix);
if (img->d() >= 1) cairo_paint(cairo_);
else cairo_mask(cairo_, pat);