From 69cc94ef23ea2b11c65a4c06e5e17aaea95a973e Mon Sep 17 00:00:00 2001 From: Drew DeVault Date: Sun, 6 Aug 2017 14:43:33 -0400 Subject: Prevent scrolling images indefinitely off-screen With this change, if you scroll the image well beyond the viewport, scrolling any amount in the other direction will immediately bring it back on screen. --- src/viewport.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'src/viewport.c') diff --git a/src/viewport.c b/src/viewport.c index d096a45..036749f 100644 --- a/src/viewport.c +++ b/src/viewport.c @@ -57,12 +57,29 @@ void imv_viewport_scale_to_actual(struct imv_viewport *view, const struct imv_te imv_viewport_center(view, tex); } -void imv_viewport_move(struct imv_viewport *view, int x, int y) +void imv_viewport_move(struct imv_viewport *view, int x, int y, + const struct imv_texture *tex) { view->x += x; view->y += y; view->redraw = 1; view->locked = 1; + int w = (int)((double)tex->width * view->scale); + int h = (int)((double)tex->height * view->scale); + int ww, wh; + SDL_GetWindowSize(view->window, &ww, &wh); + if (view->x < -w) { + view->x = -w; + } + if (view->x > ww) { + view->x = ww; + } + if (view->y < -h) { + view->y = -h; + } + if (view->y > wh) { + view->y = wh; + } } void imv_viewport_zoom(struct imv_viewport *view, const struct imv_texture *tex, enum imv_zoom_source src, int amount) -- cgit v1.2.3