Improved clear function. CPU usage DRASTICALLY reduced

2 files changed, 45 insertions, 11 deletions

diff --git a/Makefile b/Makefile
index c2ff382..aa64d30 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@ XINERAMALIBS = -L/usr/X11R6/lib -lXinerama
 XINERAMAFLAGS = -DXINERAMA
 
 nyancat:  nyan.c
-	cc -g nyan.c -o nyancat ${LIBS} ${XINERAMALIBS} ${XINERAMAINC} ${FLAGS} ${XINERAMAFLAGS}
+	cc -g nyan.c -o nyancat ${LIBS} ${XINERAMALIBS} ${XINERAMAINC} ${FLAGS} ${XINERAMAFLAGS} -ggdb
 
 install:
 	cp nyancat ${BIN}
diff --git a/nyan.c b/nyan.c
index 6824841..9660bc4 100644
--- a/nyan.c
+++ b/nyan.c
@@ -19,8 +19,6 @@
 #include <X11/extensions/Xinerama.h>

 #endif /* XINERAMA */

 

-#define CLEARSCR()      (fillsquare(screen, 0, 0, screen->w, screen->h, bgcolor))

-

 /* Type definitions */

 typedef struct {

     int x, y;

@@ -44,6 +42,7 @@ struct sparkle_instance {
 /* Predecs */

 static void add_sparkle(void);

 static void add_cat(unsigned int x, unsigned int y);

+static void clear_screen(void);

 static void draw_cats(unsigned int frame);

 static void draw_sparkles(void);

 static void fillsquare(SDL_Surface* surf, int x, int y, int w, int h, Uint32 col);

@@ -69,6 +68,7 @@ static int                  sound = 1;
 #ifdef XINERAMA

 static Display* dpy;

 #endif /* XINERAMA */

+static int                  curr_frame = 0;

 static SDL_Surface*         cat_img[5];

 static SDL_Surface*         sparkle_img[5];

 static Mix_Music*           music;

@@ -127,6 +127,24 @@ add_cat(unsigned int x, unsigned int y) {
 }

 

 void

+clear_screen(void) {

+    sparkle_instance *s = sparkles_list;

+    cat_instance *c = cat_list;

+

+    while (c) {

+        /* This is bad. These magic numbers are to make up for uneven image sizes */

+        fillsquare(screen, c->loc.x, c->loc.y - (curr_frame < 2 ? 0 : 5), cat_img[curr_frame]->w + 6, cat_img[curr_frame]->h + 5, bgcolor);

+        c = c->next;

+    }

+

+    while (s) {

+        fillsquare(screen, s->loc.x, s->loc.y, sparkle_img[s->frame]->w, sparkle_img[s->frame]->h, bgcolor);

+        s = s->next;

+    }

+}

+

+

+void

 draw_cats(unsigned int frame) {

     cat_instance* c = cat_list;;

     SDL_Rect pos;

@@ -160,11 +178,26 @@ void
 fillsquare(SDL_Surface* surf, int x, int y, int w, int h, Uint32 col) {

     int i, e;

 

-    /* Placement of random pixels for every pixel on the screen */

-    for (i = 0; i < h; i++)

-        for (e = 0; e < w; e++) {

-            putpix(surf, x + e, y + i, col);

-        }

+    if (x + w < 0 || y + h < 0 || x > surf->w || y > surf->h)

+        return;

+

+    /* Sanitising of inputs. Make sure we're not drawing off of the surface */

+    if (x + w > surf->w)

+        w = surf->w - x;

+    if (y + h > surf->h)

+        h = surf->h - y;

+    if (x < 0) {

+        w += x;

+        x = 0;

+    }

+    if (y < 0) {

+        h += y;

+        y = 0;

+    }

+

+    for (i = x; i < x + w; i++)

+        for (e = y; e < y + h; e++)

+            putpix(surf, i, e, col);

 }

 

 void

@@ -294,7 +327,7 @@ update_sparkles(void) {
 

 int main( int argc, char *argv[] )

 {

-    int i, draw_time, last_draw, curr_frame = 0;

+    int i, draw_time, last_draw;

 

     srand( time(NULL) );

 

@@ -314,6 +347,7 @@ int main( int argc, char *argv[] )
 

     load_images();

     bgcolor = SDL_MapRGB(screen->format, 0x00, 0x33, 0x66);

+    fillsquare(screen, 0, 0, screen->w, screen->h, bgcolor);

 

     if(sound) {

         Mix_OpenAudio( 44100, AUDIO_S16, 2, 256 );

@@ -342,11 +376,11 @@ int main( int argc, char *argv[] )
     {

         last_draw = SDL_GetTicks();

 

-        CLEARSCR();

+        clear_screen();

+        update_sparkles();

         draw_sparkles();

         draw_cats(curr_frame);

 

-        update_sparkles();

         handleinput();

         SDL_Flip(screen);