diff options
Diffstat (limited to 'src/drivers/Xlib')
| -rw-r--r-- | src/drivers/Xlib/Fl_Xlib_Graphics_Driver.H | 15 | ||||
| -rw-r--r-- | src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx | 1 | ||||
| -rw-r--r-- | src/drivers/Xlib/Fl_Xlib_Graphics_Driver_rect.cxx | 139 |
3 files changed, 39 insertions, 116 deletions
diff --git a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.H b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.H index 0870ebb2f..66b270b05 100644 --- a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.H +++ b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.H @@ -59,8 +59,7 @@ private: int stack_x_[20], stack_y_[20]; // translation stack allowing cumulative translations int line_delta_; virtual void set_current_(); -protected: - int xmin, ymin, xmax, ymax; // ranges of valid x/y coordinates, see set_clip_range() + int clip_max_; // +/- x/y coordinate limit (16-bit coordinate space) protected: virtual void draw_unscaled(Fl_Pixmap *pxm, float s, int XP, int YP, int WP, int HP, int cx, int cy); virtual void draw_unscaled(Fl_Bitmap *pxm, float s, int XP, int YP, int WP, int HP, int cx, int cy); @@ -155,9 +154,12 @@ protected: // --- clipped drawing (after scaling, with real screen coordinates) // --- currently specific to Fl_Xlib_Graphics_Driver (16-bit coordinate clipping) - // clip one coordinate (x or y) --- correct axis (x/y) is important ! - virtual int clip_x(int x); - virtual int clip_y(int y); + // clipping limits + virtual int clip_max() { return clip_max_; } + virtual int clip_min() { return -clip_max_; } + + // clip one coordinate (x or y) + virtual int clip_xy(int x); // clip one line virtual int clip_line(int &x1, int &y1, int &x2, int &y2); @@ -168,9 +170,6 @@ protected: // draw a line after clipping (if visible) virtual void draw_clipped_line(int x1, int y1, int x2, int y2); - // set_clip_range() - set valid coordinate range (16-bit or current window) - virtual void set_clip_range(); - // --- clipping void push_clip(int x, int y, int w, int h); int clip_box(int x, int y, int w, int h, int &X, int &Y, int &W, int &H); diff --git a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx index 41b90ec29..3a04ecb18 100644 --- a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx +++ b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver.cxx @@ -59,6 +59,7 @@ Fl_Xlib_Graphics_Driver::Fl_Xlib_Graphics_Driver(void) { #endif offset_x_ = 0; offset_y_ = 0; depth_ = 0; + clip_max_ = 32760; // clipping limit (2**15 - 8) } Fl_Xlib_Graphics_Driver::~Fl_Xlib_Graphics_Driver() { diff --git a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_rect.cxx b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_rect.cxx index a01c4042a..1080bd360 100644 --- a/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_rect.cxx +++ b/src/drivers/Xlib/Fl_Xlib_Graphics_Driver_rect.cxx @@ -41,58 +41,6 @@ // Note: the current (default) approach is to clip to the current window // boundaries instead. This can avoid drawing unecessary (invisible) objects. -#define MAXK (32760) // 2 ** 15 - K (8) - -#define CLIP_TO_WINDOW (0) // Default: 1 (clip to window), see below - -/* - Sets the coordinate space limits for clipping. - - We have two choices: - - - the entire 16-bit coordinate space (CLIP_TO_WINDOW = 0) - - the current window (Default: CLIP_TO_WINDOW != 0) - - The current approach is to use window coordinates. The macro CLIP_TO_WINDOW - (above) can be set to 0 to clip to the entire 16-bit coordinate space - instead. This can be done for testing purposes or if it turns out that - window clipping doesn't work as expected. - AlbrechtS, 09 Mar 2018 - - Implementation note: to optimize setting the clip area this could be done - when drawing starts, maybe in make_current() or something like that. - This is left for a later step. -*/ -void Fl_Xlib_Graphics_Driver::set_clip_range() { - -#if (CLIP_TO_WINDOW) // should be true (the default) - - Fl_Window *win = Fl_Window::current(); // get current window - - xmax = win->w() * scale_ + line_width_ + 1; - ymax = win->h() * scale_ + line_width_ + 1; - xmin = 0 - line_width_ - 1; - ymin = 0 - line_width_ - 1; - - // the following checks are likely unnecessary, but with large scaling - // factors ... (a little paranoid) - - if (xmax > MAXK) xmax = MAXK; - if (ymax > MAXK) ymax = MAXK; - if (xmin < -MAXK) xmin = -MAXK; - if (ymin < -MAXK) ymin = -MAXK; - -#else // use full X (16-bit) coordinate space - - xmax = MAXK; - ymax = xmax; - xmin = -xmax; - ymin = -xmax; - -#endif // CLIP_TO_WINDOW - -} // set_clip_range() - /* Liang-Barsky line clipping algorithm. For documentation see: https://en.wikipedia.org/wiki/Liang-Barsky_algorithm . @@ -114,18 +62,16 @@ void Fl_Xlib_Graphics_Driver::set_clip_range() { int Fl_Xlib_Graphics_Driver::clip_line(int &x1, int &y1, int &x2, int &y2) { - set_clip_range(); - // define variables float p1 = float(-(x2 - x1)); float p2 = float(-p1); float p3 = float(-(y2 - y1)); float p4 = float(-p3); - float q1 = float(x1 - xmin); - float q2 = float(xmax - x1); - float q3 = float(y1 - ymin); - float q4 = float(ymax - y1); + float q1 = float(x1 - clip_min()); + float q2 = float(clip_max() - x1); + float q3 = float(y1 - clip_min()); + float q4 = float(clip_max() - y1); float posmin = 1; // positive minimum float negmax = 0; // negative maximum @@ -156,6 +102,9 @@ int Fl_Xlib_Graphics_Driver::clip_line(int &x1, int &y1, int &x2, int &y2) { } } + if (negmax > posmin) // line outside clipping window + return 1; // clipped + // compute new points (note: order is important!) x2 = int(x1 + p2 * posmin); @@ -208,12 +157,12 @@ int Fl_Xlib_Graphics_Driver::clip_line(int &x1, int &y1, int &x2, int &y2) { /* clip_rect() returns 1 if the area is invisible (clipped) because ... - (a) w <= 0 or h <= 0 i.e. nothing is visible - (b) x+w < xmin or y+h < ymin i.e. left of or above visible area - (c) x > xmax or y > ymax i.e. right of or below visible area + (a) w <= 0 or h <= 0 i.e. nothing is visible + (b) x+w < clip_min() or y+h < clip_min() i.e. left of or above visible area + (c) x > clip_max() or y > clip_max() i.e. right of or below visible area - xmin, ymin, xmax, and ymax are the minimal and maximal X coordinate - values or the window bounds as defined above. + clip_min() and clip_max() are the minimal and maximal x/y coordinate values + used for clipping. In the above cases x, y, w, and h are not changed and the return value is 1 (clipped). @@ -223,69 +172,43 @@ int Fl_Xlib_Graphics_Driver::clip_line(int &x1, int &y1, int &x2, int &y2) { Use this for clipping rectangles as in fl_rect() and fl_rectf(). It is fast and convenient. - - Todo: Test for exact (filled) rectangle and border limits. If coordinates - are modified (clipped) borders should not be visible if they would be - outside the window, for instance: - - fl_line_style(FL_SOLID, 5); // line width = 5 - fl_rect(-6, 0, 100, 100); // left border should not be visible - fl_rect(-1, 0, 100, 100); // left border should be partially visible - - This is no problem with 16-bit clipping but might be relevant with - window clipping. The same applies to the bottom and right borders, resp.. */ int Fl_Xlib_Graphics_Driver::clip_rect(int &x, int &y, int &w, int &h) { - set_clip_range(); - - if (w <= 0 || h <= 0) return 1; // (a) - if (x+w < xmin || y+h < ymin) return 1; // (b) - if (x > xmax || y > ymax) return 1; // (c) + if (w <= 0 || h <= 0) return 1; // (a) + if (x+w < clip_min() || y+h < clip_min()) return 1; // (b) + if (x > clip_max() || y > clip_max()) return 1; // (c) - if (x < xmin) { w -= (xmin-x); x = xmin; } - if (y < ymin) { h -= (ymin-y); y = ymin; } - if (x+w > xmax) w = xmax - x; - if (y+h > ymax) h = ymax - y; + if (x < clip_min()) { w -= (clip_min()-x); x = clip_min(); } + if (y < clip_min()) { h -= (clip_min()-y); y = clip_min(); } + if (x+w > clip_max()) w = clip_max() - x; + if (y+h > clip_max()) h = clip_max() - y; return 0; } /* - clip_x() and clip_y() return a coordinate value clipped to the 16-bit - coordinate space or the current window (see above). + clip_xy() returns a single coordinate value clipped to the 16-bit + coordinate space. This can be used to draw horizontal and vertical lines that can be - handled by X11. Each single coordinate value can be clipped individually + handled by X. Each single coordinate value can be clipped individually and the result can be used directly, e.g. in fl_xyline() and fl_yxline(). Note 1: this can't be used for arbitrary lines (neither horizontal nor vertical). Note 2: may be changed since Fl_Xlib_Graphics_Driver::clip_line() exists. */ -int Fl_Xlib_Graphics_Driver::clip_x(int x) { +int Fl_Xlib_Graphics_Driver::clip_xy(int x) { - set_clip_range(); - - if (x < xmin) - x = xmin; - else if (x > xmax) - x = xmax; + if (x < clip_min()) + x = clip_min(); + else if (x > clip_max()) + x = clip_max(); return x; } -int Fl_Xlib_Graphics_Driver::clip_y(int y) { - - set_clip_range(); - - if (y < ymin) - y = ymin; - else if (y > ymax) - y = ymax; - return y; -} - // Missing X call: (is this the fastest way to init a 1-rectangle region?) // Windows equivalent exists, implemented inline in win32.H @@ -360,8 +283,8 @@ void Fl_Xlib_Graphics_Driver::xyline_unscaled(float x, float y, float x1) { x+=offset_x_*scale_; y+=offset_y_*scale_; x1 += offset_x_*scale_; int tw = line_width_ ? line_width_ : 1; // true line width if (x > x1) { float exch = x; x = x1; x1 = exch; } - int ix = clip_x(x+line_delta_); if (scale_ >= 2) ix -= int(scale_/2); - int iy = clip_y(y+line_delta_); + int ix = clip_xy(x+line_delta_); if (scale_ >= 2) ix -= int(scale_/2); + int iy = clip_xy(y+line_delta_); // make sure that line output by xyline(a,b,c) extends to pixel just at left of where xyline(c+1,b,d) begins int ix1 = int(x1/scale_+1.5)*scale_-1; ix1 += line_delta_; if (scale_ >= 4) ix1 -= 1; @@ -375,8 +298,8 @@ void Fl_Xlib_Graphics_Driver::yxline_unscaled(float x, float y, float y1) { x+=offset_x_*scale_; y+=offset_y_*scale_; y1 += offset_y_*scale_; int tw = line_width_ ? line_width_ : 1; // true line width if (y > y1) { float exch = y; y = y1; y1 = exch; } - int ix = clip_x(x+line_delta_); - int iy = clip_y(y+line_delta_); if (scale_ >= 2) iy -= int(scale_/2); + int ix = clip_xy(x+line_delta_); + int iy = clip_xy(y+line_delta_); if (scale_ >= 2) iy -= int(scale_/2); int iy1 = int(y1/scale_+1.5)*scale_-1; // make sure that line output by yxline(a,b,c) extends to pixel just above where yxline(a,c+1,d) begins iy1 += line_delta_; if (scale_ >= 4) iy1 -= 1; |