Date: Sat, 3 Jan 2009 22:11:18 -0500
authorSam Lantinga <slouken@libsdl.org>
Sun, 04 Jan 2009 19:33:21 +0000
changeset 29947563b99e9a49
parent 2993 2fad80c77c17
child 2995 b3f23a4b4547
Date: Sat, 3 Jan 2009 22:11:18 -0500
From: "Donny Viszneki"
Subject: Re: [SDL] Want to help with SDL 1.3?

>> > For example, here's a good quick project for someone from the TODO list:
>> > * Add diagonal line clipping to SDL_IntersectRectAndLine()

Just wanted to point out that the patch is available at
http://codebad.com/rect-line-ix.patch

I hereby grant Sam Lantinga an irrevocable non-exclusive distribution
license to this patch to do with as he wishes.
src/video/SDL_rect.c
test/Makefile.in
test/testintersections.c
     1.1 --- a/src/video/SDL_rect.c	Sun Jan 04 19:26:50 2009 +0000
     1.2 +++ b/src/video/SDL_rect.c	Sun Jan 04 19:33:21 2009 +0000
     1.3 @@ -148,13 +148,13 @@
     1.4          return SDL_TRUE;
     1.5      }
     1.6  
     1.7 -    /* Check to see if entire line is outside rect */
     1.8 +    /* Check to see if entire line is to one side of rect */
     1.9      if ((x1 < rectx1 && x2 < rectx1) || (x1 > rectx2 && x2 > rectx2) ||
    1.10          (y1 < recty1 && y2 < recty2) || (y1 > recty2 && y2 > recty2)) {
    1.11          return SDL_FALSE;
    1.12      }
    1.13  
    1.14 -    if (y1 = y2) {
    1.15 +    if (y1 == y2) {
    1.16          /* Horizontal line, easy to clip */
    1.17          if (x1 < rectx1) {
    1.18              *X1 = rectx1;
    1.19 @@ -184,7 +184,92 @@
    1.20          return SDL_TRUE;
    1.21      }
    1.22  
    1.23 -    /* FIXME: need code to clip diagonal line to rect */
    1.24 +    else
    1.25 +    {
    1.26 +    /* The task of clipping a line with finite slope ratios in a fixed-
    1.27 +     * precision coordinate space is not as immediately simple as it is
    1.28 +     * with coordinates of arbitrary precision. If the ratio of slopes
    1.29 +     * between the input line segment and the result line segment is not
    1.30 +     * a whole number, you have in fact *moved* the line segment a bit,
    1.31 +     * and there can be no avoiding it without more precision
    1.32 +     */
    1.33 +        int *x_result_[] = {X1, X2, NULL}, **x_result = x_result_;
    1.34 +        int *y_result_[] = {Y1, Y2, NULL}, **y_result = y_result_;
    1.35 +        SDL_bool intersection = SDL_FALSE;
    1.36 +        double b, m, left, right, bottom, top;
    1.37 +        int xl, xh, yl, yh;
    1.38 +
    1.39 +        /* solve mx+b line formula */
    1.40 +        m = (double)(y1-y2) / (double)(x1-x2);
    1.41 +        b = y2 - m * (double) x2;
    1.42 +
    1.43 +        /* find some linear intersections */
    1.44 +        left = (m * (double) rectx1) + b;
    1.45 +        right = (m * (double) rectx2) + b;
    1.46 +        top = (recty1 - b) / m;
    1.47 +        bottom = (recty2 - b) / m;
    1.48 +
    1.49 +        /* sort end-points' x and y components individually */
    1.50 +        if (x1 < x2) {
    1.51 +            xl = x1;
    1.52 +            xh = x2;
    1.53 +        } else {
    1.54 +            xl = x2;
    1.55 +            xh = x1;
    1.56 +        }
    1.57 +        if (y1 < y2) {
    1.58 +            yl = y1;
    1.59 +            yh = y2;
    1.60 +        } else {
    1.61 +            yl = y2;
    1.62 +            yh = y1;
    1.63 +        }
    1.64 +
    1.65 +#define RISING(a, b, c) (((a)<=(b))&&((b)<=(c)))
    1.66 +
    1.67 +        /* check for a point that's entirely inside the rect */
    1.68 +        if (RISING(rectx1, x1, rectx2) && RISING(recty1, y1, recty2)) {
    1.69 +            x_result++;
    1.70 +            y_result++;
    1.71 +            intersection = SDL_TRUE;
    1.72 +        } else /* it was determined earlier that *both* end-points are not contained */
    1.73 +
    1.74 +        if (RISING(rectx1, x2, rectx2) && RISING(recty1, y2, recty2)) {
    1.75 +            **(x_result++) = x2;
    1.76 +            **(y_result++) = y2;
    1.77 +            intersection = SDL_TRUE;
    1.78 +        }
    1.79 +
    1.80 +        if (RISING(recty1, left, recty2) && RISING(xl, rectx1, xh)) {
    1.81 +            **(x_result++) = rectx1;
    1.82 +            **(y_result++) = (int) left;
    1.83 +            intersection = SDL_TRUE;
    1.84 +        }
    1.85 +
    1.86 +        if (*x_result == NULL) return intersection;
    1.87 +        if (RISING(recty1, right, recty2) && RISING(xl, rectx2, xh)) {
    1.88 +            **(x_result++) = rectx2;
    1.89 +            **(y_result++) = (int) right;
    1.90 +            intersection = SDL_TRUE;
    1.91 +        }
    1.92 +
    1.93 +        if (*x_result == NULL) return intersection;
    1.94 +        if (RISING(rectx1, top, rectx2) && RISING(yl, recty1, yh)) {
    1.95 +            **(x_result++) = (int) top;
    1.96 +            **(y_result++) = recty1;
    1.97 +            intersection = SDL_TRUE;
    1.98 +        }
    1.99 +
   1.100 +        if (*x_result == NULL) return intersection;
   1.101 +        if (RISING(rectx1, bottom, rectx2) && RISING(yl, recty2, yh)) {
   1.102 +            **(x_result++) = (int) bottom;
   1.103 +            **(y_result++) = recty2;
   1.104 +            intersection = SDL_TRUE;
   1.105 +        }
   1.106 +
   1.107 +        return intersection;
   1.108 +    }
   1.109 +
   1.110      return SDL_FALSE;
   1.111  }
   1.112  
     2.1 --- a/test/Makefile.in	Sun Jan 04 19:26:50 2009 +0000
     2.2 +++ b/test/Makefile.in	Sun Jan 04 19:33:21 2009 +0000
     2.3 @@ -7,7 +7,7 @@
     2.4  CFLAGS  = @CFLAGS@
     2.5  LIBS	= @LIBS@
     2.6  
     2.7 -TARGETS = checkkeys$(EXE) graywin$(EXE) loopwave$(EXE) testaudioinfo$(EXE) testmultiaudio$(EXE) testalpha$(EXE) testbitmap$(EXE) testblitspeed$(EXE) testcdrom$(EXE) testcursor$(EXE) testdraw2$(EXE) testdyngl$(EXE) testerror$(EXE) testfile$(EXE) testgamma$(EXE) testgl$(EXE) testgl2$(EXE) testhread$(EXE) testiconv$(EXE) testjoystick$(EXE) testkeys$(EXE) testlock$(EXE) testoverlay2$(EXE) testoverlay$(EXE) testpalette$(EXE) testplatform$(EXE) testsem$(EXE) testsprite$(EXE) testsprite2$(EXE) testtimer$(EXE) testver$(EXE) testvidinfo$(EXE) testwin$(EXE) testwm$(EXE) testwm2$(EXE) threadwin$(EXE) torturethread$(EXE) testloadso$(EXE) testhaptic$(EXE) testmmousetablet$(EXE) 
     2.8 +TARGETS = checkkeys$(EXE) graywin$(EXE) loopwave$(EXE) testaudioinfo$(EXE) testmultiaudio$(EXE) testalpha$(EXE) testbitmap$(EXE) testblitspeed$(EXE) testcdrom$(EXE) testcursor$(EXE) testintersections$(EXE) testdraw2$(EXE) testdyngl$(EXE) testerror$(EXE) testfile$(EXE) testgamma$(EXE) testgl$(EXE) testgl2$(EXE) testhread$(EXE) testiconv$(EXE) testjoystick$(EXE) testkeys$(EXE) testlock$(EXE) testoverlay2$(EXE) testoverlay$(EXE) testpalette$(EXE) testplatform$(EXE) testsem$(EXE) testsprite$(EXE) testsprite2$(EXE) testtimer$(EXE) testver$(EXE) testvidinfo$(EXE) testwin$(EXE) testwm$(EXE) testwm2$(EXE) threadwin$(EXE) torturethread$(EXE) testloadso$(EXE) testhaptic$(EXE) testmmousetablet$(EXE)
     2.9  
    2.10  all: Makefile $(TARGETS)
    2.11  
    2.12 @@ -44,6 +44,9 @@
    2.13  testcursor$(EXE): $(srcdir)/testcursor.c
    2.14  	$(CC) -o $@ $? $(CFLAGS) $(LIBS)
    2.15  
    2.16 +testintersections$(EXE): $(srcdir)/testintersections.c $(srcdir)/common.c
    2.17 +	$(CC) -o $@ $(srcdir)/testintersections.c $(srcdir)/common.c $(CFLAGS) $(LIBS)
    2.18 +
    2.19  testdraw2$(EXE): $(srcdir)/testdraw2.c $(srcdir)/common.c
    2.20  	$(CC) -o $@ $(srcdir)/testdraw2.c $(srcdir)/common.c $(CFLAGS) $(LIBS)
    2.21  
     3.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     3.2 +++ b/test/testintersections.c	Sun Jan 04 19:33:21 2009 +0000
     3.3 @@ -0,0 +1,342 @@
     3.4 +
     3.5 +/* Simple program:  draw as many random objects on the screen as possible */
     3.6 +
     3.7 +#include <stdlib.h>
     3.8 +#include <stdio.h>
     3.9 +#include <time.h>
    3.10 +
    3.11 +#include "common.h"
    3.12 +
    3.13 +#define SWAP(typ,a,b) do{typ t=a;a=b;b=t;}while(0)
    3.14 +#define NUM_OBJECTS	100
    3.15 +
    3.16 +static CommonState *state;
    3.17 +static int num_objects;
    3.18 +static SDL_bool cycle_color;
    3.19 +static SDL_bool cycle_alpha;
    3.20 +static int cycle_direction = 1;
    3.21 +static int current_alpha = 255;
    3.22 +static int current_color = 255;
    3.23 +static SDL_BlendMode blendMode = SDL_BLENDMODE_NONE;
    3.24 +
    3.25 +void
    3.26 +DrawPoints(SDL_WindowID window)
    3.27 +{
    3.28 +    int i;
    3.29 +    int x, y;
    3.30 +    int window_w, window_h;
    3.31 +
    3.32 +    /* Query the sizes */
    3.33 +    SDL_GetWindowSize(window, &window_w, &window_h);
    3.34 +
    3.35 +    SDL_SetRenderDrawBlendMode(blendMode);
    3.36 +    for (i = 0; i < num_objects * 4; ++i) {
    3.37 +        /* Cycle the color and alpha, if desired */
    3.38 +        if (cycle_color) {
    3.39 +            current_color += cycle_direction;
    3.40 +            if (current_color < 0) {
    3.41 +                current_color = 0;
    3.42 +                cycle_direction = -cycle_direction;
    3.43 +            }
    3.44 +            if (current_color > 255) {
    3.45 +                current_color = 255;
    3.46 +                cycle_direction = -cycle_direction;
    3.47 +            }
    3.48 +        }
    3.49 +        if (cycle_alpha) {
    3.50 +            current_alpha += cycle_direction;
    3.51 +            if (current_alpha < 0) {
    3.52 +                current_alpha = 0;
    3.53 +                cycle_direction = -cycle_direction;
    3.54 +            }
    3.55 +            if (current_alpha > 255) {
    3.56 +                current_alpha = 255;
    3.57 +                cycle_direction = -cycle_direction;
    3.58 +            }
    3.59 +        }
    3.60 +        SDL_SetRenderDrawColor(255, (Uint8) current_color,
    3.61 +                               (Uint8) current_color, (Uint8) current_alpha);
    3.62 +
    3.63 +        x = rand() % window_w;
    3.64 +        y = rand() % window_h;
    3.65 +        SDL_RenderPoint(x, y);
    3.66 +    }
    3.67 +    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
    3.68 +}
    3.69 +
    3.70 +#define MAX_LINES 16
    3.71 +int num_lines = 0;
    3.72 +SDL_Rect lines[MAX_LINES];
    3.73 +static int add_line(int x1, int y1, int x2, int y2) {
    3.74 +    if (num_lines >= MAX_LINES) return 0;
    3.75 +    if ((x1 == x2) && (y1 == y2)) return 0;
    3.76 +
    3.77 +    printf("adding line (%d, %d), (%d, %d)\n", x1, y1, x2, y2);
    3.78 +    lines[num_lines].x = x1;
    3.79 +    lines[num_lines].y = y1;
    3.80 +    lines[num_lines].w = x2;
    3.81 +    lines[num_lines].h = y2;
    3.82 +
    3.83 +    return ++num_lines;
    3.84 +}
    3.85 +
    3.86 +
    3.87 +void
    3.88 +DrawLines(SDL_WindowID window)
    3.89 +{
    3.90 +    int i;
    3.91 +    int x1, y1, x2, y2;
    3.92 +    int window_w, window_h;
    3.93 +
    3.94 +    /* Query the sizes */
    3.95 +    SDL_GetWindowSize(window, &window_w, &window_h);
    3.96 +
    3.97 +    SDL_SetRenderDrawBlendMode(blendMode);
    3.98 +    for (i = 0; i < num_lines; ++i) {
    3.99 +        SDL_SetRenderDrawColor(255, 255, 255, 255);
   3.100 +
   3.101 +        if (i == -1) {
   3.102 +            SDL_RenderLine(0, 0, window_w - 1, window_h - 1);
   3.103 +            SDL_RenderLine(0, window_h - 1, window_w - 1, 0);
   3.104 +            SDL_RenderLine(0, window_h / 2, window_w - 1, window_h / 2);
   3.105 +            SDL_RenderLine(window_w / 2, 0, window_w / 2, window_h - 1);
   3.106 +        } else {
   3.107 +            SDL_RenderLine(lines[i].x, lines[i].y, lines[i].w, lines[i].h);
   3.108 +        }
   3.109 +    }
   3.110 +    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
   3.111 +}
   3.112 +
   3.113 +#define MAX_RECTS 16
   3.114 +int num_rects = 0;
   3.115 +SDL_Rect rects[MAX_RECTS];
   3.116 +static int add_rect(int x1, int y1, int x2, int y2) {
   3.117 +    if (num_rects >= MAX_RECTS) return 0;
   3.118 +    if ((x1 == x2) || (y1 == y2)) return 0;
   3.119 +
   3.120 +    if (x1 > x2) SWAP(int, x1, x2);
   3.121 +    if (y1 > y2) SWAP(int, y1, y2);
   3.122 +
   3.123 +    printf("adding rect (%d, %d), (%d, %d) [%dx%d]\n", x1, y1, x2, y2, x2-x1, y2-y1);
   3.124 +
   3.125 +    rects[num_rects].x = x1;
   3.126 +    rects[num_rects].y = y1;
   3.127 +    rects[num_rects].w = x2 - x1;
   3.128 +    rects[num_rects].h = y2 - y1;
   3.129 +
   3.130 +    return ++num_rects;
   3.131 +}
   3.132 +
   3.133 +static void
   3.134 +DrawRects(SDL_WindowID window)
   3.135 +{
   3.136 +    int i;
   3.137 +    int window_w, window_h;
   3.138 +
   3.139 +    /* Query the sizes */
   3.140 +    SDL_GetWindowSize(window, &window_w, &window_h);
   3.141 +
   3.142 +    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
   3.143 +    for (i = 0; i < num_rects; ++i) {
   3.144 +        SDL_SetRenderDrawColor(255, 127, 0, 255);
   3.145 +        SDL_RenderFill(&rects[i]);
   3.146 +    }
   3.147 +    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
   3.148 +}
   3.149 +
   3.150 +static void
   3.151 +DrawRectLineIntersections(SDL_WindowID window)
   3.152 +{
   3.153 +    int i, j, window_w, window_h;
   3.154 +
   3.155 +    /* Query the sizes */
   3.156 +    SDL_GetWindowSize(window, &window_w, &window_h);
   3.157 +
   3.158 +    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
   3.159 +
   3.160 +    for (i = 0; i < num_rects; i++)
   3.161 +    for (j = 0; j < num_lines; j++) {
   3.162 +        int x1, y1, x2, y2;
   3.163 +        SDL_Rect r;
   3.164 +        
   3.165 +        r = rects[i];
   3.166 +        x1 = lines[j].x;
   3.167 +        y1 = lines[j].y;
   3.168 +        x2 = lines[j].w;
   3.169 +        y2 = lines[j].h;
   3.170 +
   3.171 +        if (SDL_IntersectRectAndLine(&r, &x1, &y1, &x2, &y2)) {
   3.172 +            SDL_SetRenderDrawColor(0, 255, 55, 255);
   3.173 +            SDL_RenderLine(x1, y1, x2, y2);
   3.174 +        }
   3.175 +    }
   3.176 +
   3.177 +    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
   3.178 +}
   3.179 +
   3.180 +static void
   3.181 +DrawRectRectIntersections(SDL_WindowID window)
   3.182 +{
   3.183 +    int i, j;
   3.184 +
   3.185 +    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
   3.186 +
   3.187 +    for (i = 0; i < num_rects; i++)
   3.188 +    for (j = i+1; j < num_rects; j++) {
   3.189 +        SDL_Rect r;
   3.190 +        if (SDL_IntersectRect(&rects[i], &rects[j], &r)) {
   3.191 +            SDL_SetRenderDrawColor(255, 200, 0, 255);
   3.192 +            SDL_RenderFill(&r);
   3.193 +        }
   3.194 +    }
   3.195 +
   3.196 +    SDL_SetRenderDrawBlendMode(SDL_BLENDMODE_NONE);
   3.197 +}
   3.198 +
   3.199 +int
   3.200 +main(int argc, char *argv[])
   3.201 +{
   3.202 +    int mouse_begin_x = -1, mouse_begin_y = -1;
   3.203 +    int i, done;
   3.204 +    SDL_Event event;
   3.205 +    Uint32 then, now, frames;
   3.206 +
   3.207 +    /* Initialize parameters */
   3.208 +    num_objects = NUM_OBJECTS;
   3.209 +
   3.210 +    /* Initialize test framework */
   3.211 +    state = CommonCreateState(argv, SDL_INIT_VIDEO);
   3.212 +    if (!state) {
   3.213 +        return 1;
   3.214 +    }
   3.215 +    for (i = 1; i < argc;) {
   3.216 +        int consumed;
   3.217 +
   3.218 +        consumed = CommonArg(state, i);
   3.219 +        if (consumed == 0) {
   3.220 +            consumed = -1;
   3.221 +            if (SDL_strcasecmp(argv[i], "--blend") == 0) {
   3.222 +                if (argv[i + 1]) {
   3.223 +                    if (SDL_strcasecmp(argv[i + 1], "none") == 0) {
   3.224 +                        blendMode = SDL_BLENDMODE_NONE;
   3.225 +                        consumed = 2;
   3.226 +                    } else if (SDL_strcasecmp(argv[i + 1], "mask") == 0) {
   3.227 +                        blendMode = SDL_BLENDMODE_MASK;
   3.228 +                        consumed = 2;
   3.229 +                    } else if (SDL_strcasecmp(argv[i + 1], "blend") == 0) {
   3.230 +                        blendMode = SDL_BLENDMODE_BLEND;
   3.231 +                        consumed = 2;
   3.232 +                    } else if (SDL_strcasecmp(argv[i + 1], "add") == 0) {
   3.233 +                        blendMode = SDL_BLENDMODE_ADD;
   3.234 +                        consumed = 2;
   3.235 +                    } else if (SDL_strcasecmp(argv[i + 1], "mod") == 0) {
   3.236 +                        blendMode = SDL_BLENDMODE_MOD;
   3.237 +                        consumed = 2;
   3.238 +                    }
   3.239 +                }
   3.240 +            } else if (SDL_strcasecmp(argv[i], "--cyclecolor") == 0) {
   3.241 +                cycle_color = SDL_TRUE;
   3.242 +                consumed = 1;
   3.243 +            } else if (SDL_strcasecmp(argv[i], "--cyclealpha") == 0) {
   3.244 +                cycle_alpha = SDL_TRUE;
   3.245 +                consumed = 1;
   3.246 +            } else if (SDL_isdigit(*argv[i])) {
   3.247 +                num_objects = SDL_atoi(argv[i]);
   3.248 +                consumed = 1;
   3.249 +            }
   3.250 +        }
   3.251 +        if (consumed < 0) {
   3.252 +            fprintf(stderr,
   3.253 +                    "Usage: %s %s [--blend none|mask|blend|add|mod] [--cyclecolor] [--cyclealpha]\n",
   3.254 +                    argv[0], CommonUsage(state));
   3.255 +            return 1;
   3.256 +        }
   3.257 +        i += consumed;
   3.258 +    }
   3.259 +    if (!CommonInit(state)) {
   3.260 +        return 2;
   3.261 +    }
   3.262 +
   3.263 +    /* Create the windows and initialize the renderers */
   3.264 +    for (i = 0; i < state->num_windows; ++i) {
   3.265 +        SDL_SelectRenderer(state->windows[i]);
   3.266 +        SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
   3.267 +        SDL_RenderFill(NULL);
   3.268 +    }
   3.269 +
   3.270 +    srand(time(NULL));
   3.271 +
   3.272 +    /* Main render loop */
   3.273 +    frames = 0;
   3.274 +    then = SDL_GetTicks();
   3.275 +    done = 0;
   3.276 +    while (!done) {
   3.277 +        /* Check for events */
   3.278 +        ++frames;
   3.279 +        while (SDL_PollEvent(&event)) {
   3.280 +            CommonEvent(state, &event, &done);
   3.281 +            switch (event.type) {
   3.282 +            case SDL_MOUSEBUTTONDOWN:
   3.283 +                if (event.button.which == 0) {
   3.284 +                    mouse_begin_x = event.button.x;
   3.285 +                    mouse_begin_y = event.button.y;
   3.286 +                }
   3.287 +                break;
   3.288 +            case SDL_MOUSEBUTTONUP:
   3.289 +                if (event.button.which == 0) {
   3.290 +                    if (event.button.button == 3)
   3.291 +                        add_line(mouse_begin_x, mouse_begin_y, event.button.x, event.button.y);
   3.292 +                    if (event.button.button == 1)
   3.293 +                        add_rect(mouse_begin_x, mouse_begin_y, event.button.x, event.button.y);
   3.294 +                }
   3.295 +                break;
   3.296 +            case SDL_KEYDOWN:
   3.297 +                switch (event.key.keysym.sym) {
   3.298 +                    case 'l':
   3.299 +                        if (event.key.keysym.mod & KMOD_SHIFT) num_lines = 0;
   3.300 +                        else add_line(rand()%640, rand()%480, rand()%640, rand()%480);
   3.301 +                        break;
   3.302 +                    case 'r':
   3.303 +                        if (event.key.keysym.mod & KMOD_SHIFT) num_rects = 0;
   3.304 +                        else add_rect(rand()%640, rand()%480, rand()%640, rand()%480);
   3.305 +                        break;
   3.306 +                }
   3.307 +                break;
   3.308 +            case SDL_WINDOWEVENT:
   3.309 +                switch (event.window.event) {
   3.310 +                case SDL_WINDOWEVENT_EXPOSED:
   3.311 +                    SDL_SelectRenderer(event.window.windowID);
   3.312 +                    SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
   3.313 +                    SDL_RenderFill(NULL);
   3.314 +                    break;
   3.315 +                }
   3.316 +                break;
   3.317 +            default:
   3.318 +                break;
   3.319 +            }
   3.320 +        }
   3.321 +        for (i = 0; i < state->num_windows; ++i) {
   3.322 +            SDL_SelectRenderer(state->windows[i]);
   3.323 +            SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
   3.324 +            SDL_RenderFill(NULL);
   3.325 +
   3.326 +            DrawRects(state->windows[i]);
   3.327 +            DrawPoints(state->windows[i]);
   3.328 +            DrawRectRectIntersections(state->windows[i]);
   3.329 +            DrawLines(state->windows[i]);
   3.330 +            DrawRectLineIntersections(state->windows[i]);
   3.331 +
   3.332 +            SDL_RenderPresent();
   3.333 +        }
   3.334 +    }
   3.335 +
   3.336 +    /* Print out some timing information */
   3.337 +    now = SDL_GetTicks();
   3.338 +    if (now > then) {
   3.339 +        double fps = ((double) frames * 1000) / (now - then);
   3.340 +        printf("%2.2f frames per second\n", fps);
   3.341 +    }
   3.342 +    return 0;
   3.343 +}
   3.344 +
   3.345 +/* vi: set ts=4 sw=4 expandtab: */