Clean up code, save more state, pan better (440463c)

main.c

@@ -17,8 +17,7 @@
 #define DZDS 0.25
 
 struct ViewState {
-    /* image index */
-    int ci;
+    SDL_Texture* tex;
     /* image dimensions */
     int iw;
     int ih;
@@ -27,9 +26,6 @@ struct ViewState {
     /* pan position (centre of image) */
     int px;
     int py;
-    /* keep track of mouse coordinates */
-    int mx;
-    int my;
 };
 
 /* if cond is true, exit the program as a failure,
@@ -128,6 +124,35 @@ void showcoords(const SDL_MouseButtonEvent button, const struct ViewState vs) {
     fflush(stdout);
 }
 
+int handlekey(SDL_Keycode sym, struct ViewState* vs, int ci, int fc, int ww, int wh) {
+    switch (sym) {
+        /* bring image back into focus when Space is pressed */
+        case SDLK_SPACE:
+            vs->px = ww / 2;
+            vs->py = wh / 2;
+            return 2;
+            break;
+        /* exit when Esc is pressed */
+        case SDLK_ESCAPE:
+            return 4;
+            break;
+        /* navigate image list with arrow keys */
+        case SDLK_LEFT:
+        case SDLK_UP:
+            if (ci > 0) {
+                return -1;
+            }
+            break;
+        case SDLK_RIGHT:
+        case SDLK_DOWN:
+            if (ci < fc - 1) {
+                return 1;
+            }
+            break;
+    }
+    return 0;
+}
+
 void drawbg(SDL_Renderer* ren, const int ww, const int wh, const int cw, const int ch, SDL_Texture* act) {
     /* clear to background colour */
     cfail(SDL_RenderClear(ren), "clear screen", 1);
@@ -141,9 +166,9 @@ void drawbg(SDL_Renderer* ren, const int ww, const int wh, const int cw, const i
     }
 }
 
-void drawfg(SDL_Renderer* ren, const struct ViewState vs, SDL_Texture* imgtex) {
+void drawfg(SDL_Renderer* ren, const struct ViewState vs) {
     /* render image */
-    cfail(SDL_RenderCopy(ren, imgtex, NULL, &(SDL_Rect){
+    cfail(SDL_RenderCopy(ren, vs.tex, NULL, &(SDL_Rect){
         .x = vs.px - ZSH(vs.iw, vs.zoom - 1.0), .y = vs.py - ZSH(vs.ih, vs.zoom - 1.0),
         .w = ZSH(vs.iw, vs.zoom), .h = ZSH(vs.ih, vs.zoom)
     }), "display image", 1);
@@ -160,8 +185,9 @@ int main(int argc, char** argv) {
     cfail(optind >= argc, "find filename(s) in options", 0);
     int fc = argc - optind;
     SDL_Surface** isurf = loadimages(argv, fc);
-    int iw = isurf[0]->w;
-    int ih = isurf[0]->h;
+    int ci = 0;
+    int iw = isurf[ci]->w;
+    int ih = isurf[ci]->h;
 
     /* create window and renderer */
     char* title = NULL;
@@ -183,10 +209,14 @@ int main(int argc, char** argv) {
     /* make images into textures */
     int cw, ch;
     SDL_Texture* act = checker(ren, argv[0], &cw, &ch);
-    SDL_Texture** itex = calloc(fc, sizeof (SDL_Texture*));
+    struct ViewState* sl = calloc(fc, sizeof(struct ViewState));
     for (int i = 0; i < fc; i++) {
-        itex[i] = SDL_CreateTextureFromSurface(ren, isurf[i]);
-        cfail(!itex[i], "create texture", 1);
+        sl[i].tex = SDL_CreateTextureFromSurface(ren, isurf[i]);
+        cfail(!sl[i].tex, "create texture", 1);
+        sl[i].px = sl[i].iw = isurf[i]->w;
+        sl[i].px /= 2;
+        sl[i].py = sl[i].ih = isurf[i]->h;
+        sl[i].py /= 2;
         SDL_FreeSurface(isurf[i]);
     }
 
@@ -203,10 +233,8 @@ int main(int argc, char** argv) {
     /* window size */
     int ww = iw;
     int wh = ih;
-    struct ViewState vs = {
-        .ci = 0, .iw = iw, .ih = ih, .zoom = 0,
-        .px = iw / 2, .py = ih / 2, .mx = 0, .my = 0
-    };
+    /* mouse position */
+    int mx, my;
 
     while (r) {
         ef = 0;
@@ -215,52 +243,37 @@ int main(int argc, char** argv) {
 
                 case SDL_KEYUP:
                     int iic = 0;
-                    switch (ev.key.keysym.sym) {
-                        /* bring image back into focus when Space is pressed */
-                        case SDLK_SPACE:
-                            vs.px = ww / 2;
-                            vs.py = wh / 2;
-                            ef = 1;
-                            break;
-                        /* exit when Esc is pressed */
-                        case SDLK_ESCAPE:
+                    switch (handlekey(ev.key.keysym.sym, &sl[ci], ci, fc, ww, wh)) {
+                        case 4:
                             r = 0;
                             break;
-                        /* navigate image list with arrow keys */
-                        case SDLK_LEFT:
-                        case SDLK_UP:
-                            if (vs.ci > 0) {
-                                vs.ci--;
+                        case 2:
+                            ef = 1;
+                            break;
+                        case 1:
                             iic = 1;
-                            }
+                            ci++;
                             break;
-                        case SDLK_RIGHT:
-                        case SDLK_DOWN:
-                            if (vs.ci < fc - 1) {
-                                vs.ci++;
+                        case -1:
                             iic = 1;
-                            }
+                            ci--;
                             break;
                     }
                     if (iic) {
-                        cfail(SDL_QueryTexture(itex[vs.ci], NULL, NULL, &vs.iw, &vs.ih), "query texture", 1);
-                        vs.zoom = 0;
-                        vs.px = vs.iw / 2;
-                        vs.py = vs.ih / 2;
                         ef = 1;
-                        updatetitle(window, ct, &title, argv[optind + vs.ci], vs);
+                        updatetitle(window, ct, &title, argv[optind + ci], sl[ci]);
                     }
                     break;
 
                 case SDL_MOUSEBUTTONDOWN:
                     /* output coordinates of cursor in image on middle-click */
                     if (ev.button.button == 2) {
-                        showcoords(ev.button, vs);
+                        showcoords(ev.button, sl[ci]);
                     }
                     /* bring image back into focus on right-click */
                     if (ev.button.button == 3) {
-                        vs.px = ww / 2;
-                        vs.py = wh / 2;
+                        sl[ci].px = ww / 2;
+                        sl[ci].py = wh / 2;
                         ef = 1;
                     }
                     break;
@@ -268,31 +281,32 @@ int main(int argc, char** argv) {
                 case SDL_MOUSEMOTION:
                     /* pan-dragging if mouse is down */
                     if (SDL_GetMouseState(NULL, NULL) & SDL_BUTTON(1)) {
-                        int sw = ZSH(vs.iw, vs.zoom - 1.0);
-                        int sh = ZSH(vs.ih, vs.zoom - 1.0);
-                        /* clamp panning to edges of window,
-                        unless zoomed image is bigger than window */
-                        if (2 * sw > ww) {
-                            vs.px += ev.motion.xrel;
-                        } else {
-                            vs.px = CLAMP(sw, vs.px + ev.motion.xrel, ww - sw);
-                        }
-                        if (2 * sh > wh) {
-                            vs.py += ev.motion.yrel;
-                        } else {
-                            vs.py = CLAMP(sh, vs.py + ev.motion.yrel, wh - sh);
-                        }
+                        int sw = ZSH(sl[ci].iw, sl[ci].zoom - 1.0);
+                        int sh = ZSH(sl[ci].ih, sl[ci].zoom - 1.0);
+                        /* clamp panning to edges of window */
+                        int big = 2 * sw > ww;
+                        sl[ci].px = CLAMP(
+                            big ? ww - sw : sw,
+                            sl[ci].px + ev.motion.xrel,
+                            big ? sw : ww - sw
+                        );
+                        big = 2 * sh > wh;
+                        sl[ci].py = CLAMP(
+                            big ? wh - sh : sh,
+                            sl[ci].py + ev.motion.yrel,
+                            big ? sh : wh - sh
+                        );
                         ef = 1;
                     }
-                    vs.mx = ev.motion.x;
-                    vs.my = ev.motion.y;
+                    mx = ev.motion.x;
+                    my = ev.motion.y;
                     break;
 
                 case SDL_MOUSEWHEEL:
                     /* scrolling changes zoom */
-                    vs.zoom += DZDS * ev.wheel.y;
-                    vs.px = vs.mx - ZSH((vs.mx - vs.px), DZDS * ev.wheel.y);
-                    vs.py = vs.my - ZSH((vs.my - vs.py), DZDS * ev.wheel.y);
+                    sl[ci].zoom += DZDS * ev.wheel.y;
+                    sl[ci].px = mx - ZSH((mx - sl[ci].px), DZDS * ev.wheel.y);
+                    sl[ci].py = my - ZSH((my - sl[ci].py), DZDS * ev.wheel.y);
                     ef = 1;
                     break;
 
@@ -323,7 +337,7 @@ int main(int argc, char** argv) {
 
         if (ef) {
             drawbg(ren, ww, wh, cw, ch, act);
-            drawfg(ren, vs, itex[vs.ci]);
+            drawfg(ren, sl[ci]);
             SDL_RenderPresent(ren);
         }
 


...	...	@@ -17,8 +17,7 @@
17	17	#define DZDS 0.25
18	18
19	19	struct ViewState {
20		- /* image index */
21		- int ci;
	20	+ SDL_Texture* tex;
22	21	/* image dimensions */
23	22	int iw;
24	23	int ih;
...	...	@@ -27,9 +26,6 @@ struct ViewState {
27	26	/* pan position (centre of image) */
28	27	int px;
29	28	int py;
30		- /* keep track of mouse coordinates */
31		- int mx;
32		- int my;
33	29	};
34	30
35	31	/* if cond is true, exit the program as a failure,
...	...	@@ -128,6 +124,35 @@ void showcoords(const SDL_MouseButtonEvent button, const struct ViewState vs) {
128	124	fflush(stdout);
129	125	}
130	126
	127	+int handlekey(SDL_Keycode sym, struct ViewState* vs, int ci, int fc, int ww, int wh) {
	128	+ switch (sym) {
	129	+ /* bring image back into focus when Space is pressed */
	130	+ case SDLK_SPACE:
	131	+ vs->px = ww / 2;
	132	+ vs->py = wh / 2;
	133	+ return 2;
	134	+ break;
	135	+ /* exit when Esc is pressed */
	136	+ case SDLK_ESCAPE:
	137	+ return 4;
	138	+ break;
	139	+ /* navigate image list with arrow keys */
	140	+ case SDLK_LEFT:
	141	+ case SDLK_UP:
	142	+ if (ci > 0) {
	143	+ return -1;
	144	+ }
	145	+ break;
	146	+ case SDLK_RIGHT:
	147	+ case SDLK_DOWN:
	148	+ if (ci < fc - 1) {
	149	+ return 1;
	150	+ }
	151	+ break;
	152	+ }
	153	+ return 0;
	154	+}
	155	+
131	156	void drawbg(SDL_Renderer* ren, const int ww, const int wh, const int cw, const int ch, SDL_Texture* act) {
132	157	/* clear to background colour */
133	158	cfail(SDL_RenderClear(ren), "clear screen", 1);
...	...	@@ -141,9 +166,9 @@ void drawbg(SDL_Renderer* ren, const int ww, const int wh, const int cw, const i
141	166	}
142	167	}
143	168
144		-void drawfg(SDL_Renderer* ren, const struct ViewState vs, SDL_Texture* imgtex) {
	169	+void drawfg(SDL_Renderer* ren, const struct ViewState vs) {
145	170	/* render image */
146		- cfail(SDL_RenderCopy(ren, imgtex, NULL, &(SDL_Rect){
	171	+ cfail(SDL_RenderCopy(ren, vs.tex, NULL, &(SDL_Rect){
147	172	.x = vs.px - ZSH(vs.iw, vs.zoom - 1.0), .y = vs.py - ZSH(vs.ih, vs.zoom - 1.0),
148	173	.w = ZSH(vs.iw, vs.zoom), .h = ZSH(vs.ih, vs.zoom)
149	174	}), "display image", 1);
...	...	@@ -160,8 +185,9 @@ int main(int argc, char** argv) {
160	185	cfail(optind >= argc, "find filename(s) in options", 0);
161	186	int fc = argc - optind;
162	187	SDL_Surface** isurf = loadimages(argv, fc);
163		- int iw = isurf[0]->w;
164		- int ih = isurf[0]->h;
	188	+ int ci = 0;
	189	+ int iw = isurf[ci]->w;
	190	+ int ih = isurf[ci]->h;
165	191
166	192	/* create window and renderer */
167	193	char* title = NULL;
...	...	@@ -183,10 +209,14 @@ int main(int argc, char** argv) {
183	209	/* make images into textures */
184	210	int cw, ch;
185	211	SDL_Texture* act = checker(ren, argv[0], &cw, &ch);
186		- SDL_Texture** itex = calloc(fc, sizeof (SDL_Texture*));
	212	+ struct ViewState* sl = calloc(fc, sizeof(struct ViewState));
187	213	for (int i = 0; i < fc; i++) {
188		- itex[i] = SDL_CreateTextureFromSurface(ren, isurf[i]);
189		- cfail(!itex[i], "create texture", 1);
	214	+ sl[i].tex = SDL_CreateTextureFromSurface(ren, isurf[i]);
	215	+ cfail(!sl[i].tex, "create texture", 1);
	216	+ sl[i].px = sl[i].iw = isurf[i]->w;
	217	+ sl[i].px /= 2;
	218	+ sl[i].py = sl[i].ih = isurf[i]->h;
	219	+ sl[i].py /= 2;
190	220	SDL_FreeSurface(isurf[i]);
191	221	}
192	222
...	...	@@ -203,10 +233,8 @@ int main(int argc, char** argv) {
203	233	/* window size */
204	234	int ww = iw;
205	235	int wh = ih;
206		- struct ViewState vs = {
207		- .ci = 0, .iw = iw, .ih = ih, .zoom = 0,
208		- .px = iw / 2, .py = ih / 2, .mx = 0, .my = 0
209		- };
	236	+ /* mouse position */
	237	+ int mx, my;
210	238
211	239	while (r) {
212	240	ef = 0;
...	...	@@ -215,52 +243,37 @@ int main(int argc, char** argv) {
215	243
216	244	case SDL_KEYUP:
217	245	int iic = 0;
218		- switch (ev.key.keysym.sym) {
219		- /* bring image back into focus when Space is pressed */
220		- case SDLK_SPACE:
221		- vs.px = ww / 2;
222		- vs.py = wh / 2;
223		- ef = 1;
224		- break;
225		- /* exit when Esc is pressed */
226		- case SDLK_ESCAPE:
	246	+ switch (handlekey(ev.key.keysym.sym, &sl[ci], ci, fc, ww, wh)) {
	247	+ case 4:
227	248	r = 0;
228	249	break;
229		- /* navigate image list with arrow keys */
230		- case SDLK_LEFT:
231		- case SDLK_UP:
232		- if (vs.ci > 0) {
233		- vs.ci--;
	250	+ case 2:
	251	+ ef = 1;
	252	+ break;
	253	+ case 1:
234	254	iic = 1;
235		- }
	255	+ ci++;
236	256	break;
237		- case SDLK_RIGHT:
238		- case SDLK_DOWN:
239		- if (vs.ci < fc - 1) {
240		- vs.ci++;
	257	+ case -1:
241	258	iic = 1;
242		- }
	259	+ ci--;
243	260	break;
244	261	}
245	262	if (iic) {
246		- cfail(SDL_QueryTexture(itex[vs.ci], NULL, NULL, &vs.iw, &vs.ih), "query texture", 1);
247		- vs.zoom = 0;
248		- vs.px = vs.iw / 2;
249		- vs.py = vs.ih / 2;
250	263	ef = 1;
251		- updatetitle(window, ct, &title, argv[optind + vs.ci], vs);
	264	+ updatetitle(window, ct, &title, argv[optind + ci], sl[ci]);
252	265	}
253	266	break;
254	267
255	268	case SDL_MOUSEBUTTONDOWN:
256	269	/* output coordinates of cursor in image on middle-click */
257	270	if (ev.button.button == 2) {
258		- showcoords(ev.button, vs);
	271	+ showcoords(ev.button, sl[ci]);
259	272	}
260	273	/* bring image back into focus on right-click */
261	274	if (ev.button.button == 3) {
262		- vs.px = ww / 2;
263		- vs.py = wh / 2;
	275	+ sl[ci].px = ww / 2;
	276	+ sl[ci].py = wh / 2;
264	277	ef = 1;
265	278	}
266	279	break;
...	...	@@ -268,31 +281,32 @@ int main(int argc, char** argv) {
268	281	case SDL_MOUSEMOTION:
269	282	/* pan-dragging if mouse is down */
270	283	if (SDL_GetMouseState(NULL, NULL) & SDL_BUTTON(1)) {
271		- int sw = ZSH(vs.iw, vs.zoom - 1.0);
272		- int sh = ZSH(vs.ih, vs.zoom - 1.0);
273		- /* clamp panning to edges of window,
274		- unless zoomed image is bigger than window */
275		- if (2 * sw > ww) {
276		- vs.px += ev.motion.xrel;
277		- } else {
278		- vs.px = CLAMP(sw, vs.px + ev.motion.xrel, ww - sw);
279		- }
280		- if (2 * sh > wh) {
281		- vs.py += ev.motion.yrel;
282		- } else {
283		- vs.py = CLAMP(sh, vs.py + ev.motion.yrel, wh - sh);
284		- }
	284	+ int sw = ZSH(sl[ci].iw, sl[ci].zoom - 1.0);
	285	+ int sh = ZSH(sl[ci].ih, sl[ci].zoom - 1.0);
	286	+ /* clamp panning to edges of window */
	287	+ int big = 2 * sw > ww;
	288	+ sl[ci].px = CLAMP(
	289	+ big ? ww - sw : sw,
	290	+ sl[ci].px + ev.motion.xrel,
	291	+ big ? sw : ww - sw
	292	+ );
	293	+ big = 2 * sh > wh;
	294	+ sl[ci].py = CLAMP(
	295	+ big ? wh - sh : sh,
	296	+ sl[ci].py + ev.motion.yrel,
	297	+ big ? sh : wh - sh
	298	+ );
285	299	ef = 1;
286	300	}
287		- vs.mx = ev.motion.x;
288		- vs.my = ev.motion.y;
	301	+ mx = ev.motion.x;
	302	+ my = ev.motion.y;
289	303	break;
290	304
291	305	case SDL_MOUSEWHEEL:
292	306	/* scrolling changes zoom */
293		- vs.zoom += DZDS * ev.wheel.y;
294		- vs.px = vs.mx - ZSH((vs.mx - vs.px), DZDS * ev.wheel.y);
295		- vs.py = vs.my - ZSH((vs.my - vs.py), DZDS * ev.wheel.y);
	307	+ sl[ci].zoom += DZDS * ev.wheel.y;
	308	+ sl[ci].px = mx - ZSH((mx - sl[ci].px), DZDS * ev.wheel.y);
	309	+ sl[ci].py = my - ZSH((my - sl[ci].py), DZDS * ev.wheel.y);
296	310	ef = 1;
297	311	break;
298	312
...	...	@@ -323,7 +337,7 @@ int main(int argc, char** argv) {
323	337
324	338	if (ef) {
325	339	drawbg(ren, ww, wh, cw, ch, act);
326		- drawfg(ren, vs, itex[vs.ci]);
	340	+ drawfg(ren, sl[ci]);
327	341	SDL_RenderPresent(ren);
328	342	}
329	343
330	344

iv