Fixed X11 line implementation - clip lines that are going to go outside the window.
--- a/src/video/x11/SDL_x11render.c Fri Dec 11 09:57:54 2009 +0000
+++ b/src/video/x11/SDL_x11render.c Fri Dec 11 09:59:36 2009 +0000
@@ -23,6 +23,8 @@
#if SDL_VIDEO_RENDER_X11
+#include <limits.h> /* For INT_MIN and INT_MAX */
+
#include "SDL_x11video.h"
#include "../SDL_rect_c.h"
#include "../SDL_pixels_c.h"
@@ -647,26 +649,134 @@
SDL_Window *window = SDL_GetWindowFromID(renderer->window);
SDL_Rect clip, rect;
unsigned long foreground;
+ XPoint *xpoints, *xpoint;
+ int i, xcount;
+ int minx, miny;
+ int maxx, maxy;
clip.x = 0;
clip.y = 0;
clip.w = window->w;
clip.h = window->h;
- if (data->makedirty) {
- /* Get the smallest rectangle that contains everything */
- SDL_EnclosePoints(points, count, NULL, &rect);
- if (!SDL_IntersectRect(&rect, &clip, &rect)) {
- /* Nothing to draw */
- return 0;
- }
- SDL_AddDirtyRect(&data->dirty, &rect);
- }
-
foreground = renderdrawcolor(renderer, 1);
XSetForeground(data->display, data->gc, foreground);
- /* FIXME: Can we properly handle lines that extend beyond visible space? */
- //XDrawLine(data->display, data->drawable, data->gc, x1, y1, x2, y2);
+
+ xpoint = xpoints = SDL_stack_alloc(XPoint, count);
+ xcount = 0;
+ minx = INT_MAX;
+ miny = INT_MAX;
+ maxx = INT_MIN;
+ maxy = INT_MIN;
+ for (i = 0; i < count; ++i) {
+ int x = points[i].x;
+ int y = points[i].y;
+
+ /* If the point is inside the window, add it to the list */
+ if (x >= 0 && x < window->w && y >= 0 && y < window->h) {
+ if (x < minx) {
+ minx = x;
+ } else if (x > maxx) {
+ maxx = x;
+ }
+ if (y < miny) {
+ miny = y;
+ } else if (y > maxy) {
+ maxy = y;
+ }
+ xpoint->x = (short)x;
+ xpoint->y = (short)y;
+ ++xpoint;
+ ++xcount;
+ continue;
+ }
+
+ /* We need to clip the line segments joined by this point */
+ if (xcount > 0) {
+ int x1 = xpoint[-1].x;
+ int y1 = xpoint[-1].y;
+ int x2 = x;
+ int y2 = y;
+ if (SDL_IntersectRectAndLine(&clip, &x1, &y1, &x2, &y2)) {
+ if (x2 < minx) {
+ minx = x2;
+ } else if (x2 > maxx) {
+ maxx = x2;
+ }
+ if (y2 < miny) {
+ miny = y2;
+ } else if (y2 > maxy) {
+ maxy = y2;
+ }
+ xpoint->x = (short)x2;
+ xpoint->y = (short)y2;
+ ++xpoint;
+ ++xcount;
+ }
+ XDrawLines(data->display, data->drawable, data->gc,
+ xpoints, xcount, CoordModeOrigin);
+ if (xpoints[0].x != x2 || xpoints[0].y != y2) {
+ XDrawPoint(data->display, data->drawable, data->gc, x2, y2);
+ }
+ if (data->makedirty) {
+ SDL_Rect rect;
+
+ rect.x = minx;
+ rect.y = miny;
+ rect.w = (maxx - minx) + 1;
+ rect.h = (maxy - miny) + 1;
+ SDL_AddDirtyRect(&data->dirty, &rect);
+ }
+ xpoint = xpoints;
+ xcount = 0;
+ minx = INT_MAX;
+ miny = INT_MAX;
+ maxx = INT_MIN;
+ maxy = INT_MIN;
+ }
+ if (i < (count-1)) {
+ int x1 = x;
+ int y1 = y;
+ int x2 = points[i+1].x;
+ int y2 = points[i+1].y;
+ if (SDL_IntersectRectAndLine(&clip, &x1, &y1, &x2, &y2)) {
+ if (x1 < minx) {
+ minx = x1;
+ } else if (x1 > maxx) {
+ maxx = x1;
+ }
+ if (y1 < miny) {
+ miny = y1;
+ } else if (y1 > maxy) {
+ maxy = y1;
+ }
+ xpoint->x = (short)x1;
+ xpoint->y = (short)y1;
+ ++xpoint;
+ ++xcount;
+ }
+ }
+ }
+ if (xcount > 1) {
+ int x2 = xpoint[-1].x;
+ int y2 = xpoint[-1].y;
+ XDrawLines(data->display, data->drawable, data->gc, xpoints, xcount,
+ CoordModeOrigin);
+ if (xpoints[0].x != x2 || xpoints[0].y != y2) {
+ XDrawPoint(data->display, data->drawable, data->gc, x2, y2);
+ }
+ if (data->makedirty) {
+ SDL_Rect rect;
+
+ rect.x = minx;
+ rect.y = miny;
+ rect.w = (maxx - minx) + 1;
+ rect.h = (maxy - miny) + 1;
+ SDL_AddDirtyRect(&data->dirty, &rect);
+ }
+ }
+ SDL_stack_free(xpoints);
+
return 0;
}
--- a/src/video/x11/SDL_x11sym.h Fri Dec 11 09:57:54 2009 +0000
+++ b/src/video/x11/SDL_x11sym.h Fri Dec 11 09:59:36 2009 +0000
@@ -95,6 +95,7 @@
SDL_X11_SYM(int,XPending,(Display* a),(a),return)
SDL_X11_SYM(int,XPutImage,(Display* a,Drawable b,GC c,XImage* d,int e,int f,int g,int h,unsigned int i,unsigned int j),(a,b,c,d,e,f,g,h,i,j),return)
SDL_X11_SYM(int,XDrawLines,(Display* a, Drawable b, GC c, XPoint* d, int e, int f),(a,b,c,d,e,f),return)
+SDL_X11_SYM(int,XDrawPoint,(Display* a, Drawable b, GC c, int d, int e),(a,b,c,d,e),return)
SDL_X11_SYM(int,XDrawPoints,(Display* a, Drawable b, GC c, XPoint* d, int e, int f),(a,b,c,d,e,f),return)
SDL_X11_SYM(int,XQueryColors,(Display* a,Colormap b,XColor* c,int d),(a,b,c,d),return)
SDL_X11_SYM(int,XQueryKeymap,(Display* a,char *b),(a,b),return)