1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
#include "viewport.h"
struct imv_viewport {
double scale;
struct {
int width, height;
} window; /* window dimensions */
struct {
int width, height;
} buffer; /* rendering buffer dimensions */
int x, y;
int redraw;
int playing;
int locked;
};
static void input_xy_to_render_xy(struct imv_viewport *view, int *x, int *y)
{
*x *= view->buffer.width / view->window.width;
*y *= view->buffer.height / view->window.height;
}
struct imv_viewport *imv_viewport_create(int window_width, int window_height,
int buffer_width, int buffer_height)
{
struct imv_viewport *view = malloc(sizeof *view);
view->window.width = window_width;
view->window.height = window_height;
view->buffer.width = buffer_width;
view->buffer.height = buffer_height;
view->scale = 1;
view->x = view->y = view->redraw = 0;
view->playing = 1;
view->locked = 0;
return view;
}
void imv_viewport_free(struct imv_viewport *view)
{
free(view);
}
void imv_viewport_set_playing(struct imv_viewport *view, bool playing)
{
view->playing = playing;
}
bool imv_viewport_is_playing(struct imv_viewport *view)
{
return view->playing;
}
void imv_viewport_toggle_playing(struct imv_viewport *view)
{
view->playing = !view->playing;
}
void imv_viewport_scale_to_actual(struct imv_viewport *view, const struct imv_image *image)
{
view->scale = 1;
view->redraw = 1;
view->locked = 1;
imv_viewport_center(view, image);
}
void imv_viewport_get_offset(struct imv_viewport *view, int *x, int *y)
{
if(x) {
*x = view->x;
}
if(y) {
*y = view->y;
}
}
void imv_viewport_get_scale(struct imv_viewport *view, double *scale)
{
if(scale) {
*scale = view->scale;
}
}
void imv_viewport_move(struct imv_viewport *view, int x, int y,
const struct imv_image *image)
{
input_xy_to_render_xy(view, &x, &y);
view->x += x;
view->y += y;
view->redraw = 1;
view->locked = 1;
int w = (int)(imv_image_width(image) * view->scale);
int h = (int)(imv_image_height(image) * view->scale);
if (view->x < -w) {
view->x = -w;
}
if (view->x > view->buffer.width) {
view->x = view->buffer.width;
}
if (view->y < -h) {
view->y = -h;
}
if (view->y > view->buffer.height) {
view->y = view->buffer.height;
}
}
void imv_viewport_zoom(struct imv_viewport *view, const struct imv_image *image,
enum imv_zoom_source src, int mouse_x, int mouse_y, int amount)
{
double prev_scale = view->scale;
int x, y;
const int image_width = imv_image_width(image);
const int image_height = imv_image_height(image);
/* x and y cordinates are relative to the image */
if(src == IMV_ZOOM_MOUSE) {
input_xy_to_render_xy(view, &mouse_x, &mouse_y);
x = mouse_x - view->x;
y = mouse_y - view->y;
} else {
x = view->scale * image_width / 2;
y = view->scale * image_height / 2;
}
const int scaled_width = image_width * view->scale;
const int scaled_height = image_height * view->scale;
const int ic_x = view->x + scaled_width/2;
const int ic_y = view->y + scaled_height/2;
const int wc_x = view->buffer.width/2;
const int wc_y = view->buffer.height/2;
double delta_scale = 0.04 * view->buffer.width * amount / image_width;
view->scale += delta_scale;
const double min_scale = 0.1;
const double max_scale = 100;
if(view->scale > max_scale) {
view->scale = max_scale;
} else if (view->scale < min_scale) {
view->scale = min_scale;
}
if(view->scale < prev_scale) {
if(scaled_width < view->buffer.width) {
x = scaled_width/2 - (ic_x - wc_x)*2;
}
if(scaled_height < view->buffer.height) {
y = scaled_height/2 - (ic_y - wc_y)*2;
}
} else {
if(scaled_width < view->buffer.width) {
x = scaled_width/2;
}
if(scaled_height < view->buffer.height) {
y = scaled_height/2;
}
}
const double changeX = x - (x * (view->scale / prev_scale));
const double changeY = y - (y * (view->scale / prev_scale));
view->x += changeX;
view->y += changeY;
view->redraw = 1;
view->locked = 1;
}
void imv_viewport_center(struct imv_viewport *view, const struct imv_image *image)
{
const int image_width = imv_image_width(image);
const int image_height = imv_image_height(image);
view->x = (view->buffer.width - image_width * view->scale) / 2;
view->y = (view->buffer.height - image_height * view->scale) / 2;
view->locked = 1;
view->redraw = 1;
}
void imv_viewport_scale_to_window(struct imv_viewport *view, const struct imv_image *image)
{
const int image_width = imv_image_width(image);
const int image_height = imv_image_height(image);
const double window_aspect = (double)view->buffer.width / (double)view->buffer.height;
const double image_aspect = (double)image_width / (double)image_height;
if(window_aspect > image_aspect) {
/* Image will become too tall before it becomes too wide */
view->scale = (double)view->buffer.height / (double)image_height;
} else {
/* Image will become too wide before it becomes too tall */
view->scale = (double)view->buffer.width / (double)image_width;
}
imv_viewport_center(view, image);
view->locked = 0;
}
void imv_viewport_set_redraw(struct imv_viewport *view)
{
view->redraw = 1;
}
void imv_viewport_update(struct imv_viewport *view,
int window_width, int window_height,
int buffer_width, int buffer_height,
struct imv_image *image)
{
view->window.width = window_width;
view->window.height = window_height;
view->buffer.width = buffer_width;
view->buffer.height = buffer_height;
view->redraw = 1;
if(view->locked) {
return;
}
imv_viewport_center(view, image);
imv_viewport_scale_to_window(view, image);
}
int imv_viewport_needs_redraw(struct imv_viewport *view)
{
int redraw = 0;
if(view->redraw) {
redraw = 1;
view->redraw = 0;
}
return redraw;
}
/* vim:set ts=2 sts=2 sw=2 et: */
|
