glamor_dash.c revision 35c4bbdf 
1/*
2 * Copyright © 2014 Keith Packard
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission.  The copyright holders make no representations
11 * about the suitability of this software for any purpose.  It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#include "glamor_priv.h"
24#include "glamor_program.h"
25#include "glamor_transform.h"
26#include "glamor_transfer.h"
27#include "glamor_prepare.h"
28
29static const char dash_vs_vars[] =
30    "attribute vec3 primitive;\n"
31    "varying float dash_offset;\n";
32
33static const char dash_vs_exec[] =
34    "       dash_offset = primitive.z / dash_length;\n"
35    GLAMOR_POS(gl_Position, primitive.xy);
36
37static const char dash_fs_vars[] =
38    "varying float dash_offset;\n";
39
40static const char on_off_fs_exec[] =
41    "       float pattern = texture2D(dash, vec2(dash_offset, 0.5)).w;\n"
42    "       if (pattern == 0.0)\n"
43    "               discard;\n";
44
45/* XXX deal with stippled double dashed lines once we have stippling support */
46static const char double_fs_exec[] =
47    "       float pattern = texture2D(dash, vec2(dash_offset, 0.5)).w;\n"
48    "       if (pattern == 0.0)\n"
49    "               gl_FragColor = bg;\n"
50    "       else\n"
51    "               gl_FragColor = fg;\n";
52
53
54static const glamor_facet glamor_facet_on_off_dash_lines = {
55    .version = 130,
56    .name = "poly_lines_on_off_dash",
57    .vs_vars = dash_vs_vars,
58    .vs_exec = dash_vs_exec,
59    .fs_vars = dash_fs_vars,
60    .fs_exec = on_off_fs_exec,
61    .locations = glamor_program_location_dash,
62};
63
64static const glamor_facet glamor_facet_double_dash_lines = {
65    .version = 130,
66    .name = "poly_lines_double_dash",
67    .vs_vars = dash_vs_vars,
68    .vs_exec = dash_vs_exec,
69    .fs_vars = dash_fs_vars,
70    .fs_exec = double_fs_exec,
71    .locations = (glamor_program_location_dash|
72                  glamor_program_location_fg|
73                  glamor_program_location_bg),
74};
75
76static PixmapPtr
77glamor_get_dash_pixmap(GCPtr gc)
78{
79    glamor_gc_private *gc_priv = glamor_get_gc_private(gc);
80    ScreenPtr   screen = gc->pScreen;
81    PixmapPtr   pixmap;
82    int         offset;
83    int         d;
84    uint32_t    pixel;
85    GCPtr       scratch_gc;
86
87    if (gc_priv->dash)
88        return gc_priv->dash;
89
90    offset = 0;
91    for (d = 0; d < gc->numInDashList; d++)
92        offset += gc->dash[d];
93
94    pixmap = glamor_create_pixmap(screen, offset, 1, 8, 0);
95    if (!pixmap)
96        goto bail;
97
98    scratch_gc = GetScratchGC(8, screen);
99    if (!scratch_gc)
100        goto bail_pixmap;
101
102    pixel = 0xffffffff;
103    offset = 0;
104    for (d = 0; d < gc->numInDashList; d++) {
105        xRectangle      rect;
106        ChangeGCVal     changes;
107
108        changes.val = pixel;
109        (void) ChangeGC(NullClient, scratch_gc,
110                        GCForeground, &changes);
111        ValidateGC(&pixmap->drawable, scratch_gc);
112        rect.x = offset;
113        rect.y = 0;
114        rect.width = gc->dash[d];
115        rect.height = 1;
116        scratch_gc->ops->PolyFillRect (&pixmap->drawable, scratch_gc, 1, &rect);
117        offset += gc->dash[d];
118        pixel = ~pixel;
119    }
120    FreeScratchGC(scratch_gc);
121
122    gc_priv->dash = pixmap;
123    return pixmap;
124
125bail_pixmap:
126    glamor_destroy_pixmap(pixmap);
127bail:
128    return NULL;
129}
130
131static glamor_program *
132glamor_dash_setup(DrawablePtr drawable, GCPtr gc)
133{
134    ScreenPtr screen = drawable->pScreen;
135    glamor_screen_private *glamor_priv = glamor_get_screen_private(screen);
136    PixmapPtr pixmap = glamor_get_drawable_pixmap(drawable);
137    glamor_pixmap_private *pixmap_priv = glamor_get_pixmap_private(pixmap);
138    PixmapPtr dash_pixmap;
139    glamor_pixmap_private *dash_priv;
140    glamor_program *prog;
141
142    if (!GLAMOR_PIXMAP_PRIV_HAS_FBO(pixmap_priv))
143        goto bail;
144
145    if (gc->lineWidth != 0)
146        goto bail;
147
148    dash_pixmap = glamor_get_dash_pixmap(gc);
149    dash_priv = glamor_get_pixmap_private(pixmap);
150
151    if (!GLAMOR_PIXMAP_PRIV_HAS_FBO(dash_priv))
152        goto bail;
153
154    glamor_make_current(glamor_priv);
155
156    switch (gc->lineStyle) {
157    case LineOnOffDash:
158        prog = glamor_use_program_fill(pixmap, gc,
159                                       &glamor_priv->on_off_dash_line_progs,
160                                       &glamor_facet_on_off_dash_lines);
161        if (!prog)
162            goto bail;
163        break;
164    case LineDoubleDash:
165        if (gc->fillStyle != FillSolid)
166            goto bail;
167
168        prog = &glamor_priv->double_dash_line_prog;
169
170        if (!prog->prog) {
171            if (!glamor_build_program(screen, prog,
172                                      &glamor_facet_double_dash_lines,
173                                      NULL, NULL, NULL))
174                goto bail;
175        }
176
177        if (!glamor_use_program(pixmap, gc, prog, NULL))
178            goto bail;
179
180        glamor_set_color(pixmap, gc->fgPixel, prog->fg_uniform);
181        glamor_set_color(pixmap, gc->bgPixel, prog->bg_uniform);
182        break;
183
184    default:
185        goto bail;
186    }
187
188
189    /* Set the dash pattern as texture 1 */
190
191    glamor_bind_texture(glamor_priv, GL_TEXTURE1, dash_priv->fbo, FALSE);
192    glUniform1i(prog->dash_uniform, 1);
193    glUniform1f(prog->dash_length_uniform, dash_pixmap->drawable.width);
194
195    return prog;
196
197bail:
198    return NULL;
199}
200
201static void
202glamor_dash_loop(DrawablePtr drawable, GCPtr gc, glamor_program *prog,
203                 int n, GLenum mode)
204{
205    PixmapPtr pixmap = glamor_get_drawable_pixmap(drawable);
206    glamor_pixmap_private *pixmap_priv = glamor_get_pixmap_private(pixmap);
207    int box_index;
208    int off_x, off_y;
209
210    glEnable(GL_SCISSOR_TEST);
211
212    glamor_pixmap_loop(pixmap_priv, box_index) {
213        int nbox = RegionNumRects(gc->pCompositeClip);
214        BoxPtr box = RegionRects(gc->pCompositeClip);
215
216        glamor_set_destination_drawable(drawable, box_index, TRUE, TRUE,
217                                        prog->matrix_uniform, &off_x, &off_y);
218
219        while (nbox--) {
220            glScissor(box->x1 + off_x,
221                      box->y1 + off_y,
222                      box->x2 - box->x1,
223                      box->y2 - box->y1);
224            box++;
225            glDrawArrays(mode, 0, n);
226        }
227    }
228
229    glDisable(GL_SCISSOR_TEST);
230    glDisableVertexAttribArray(GLAMOR_VERTEX_POS);
231}
232
233static int
234glamor_line_length(short x1, short y1, short x2, short y2)
235{
236    return max(abs(x2 - x1), abs(y2 - y1));
237}
238
239Bool
240glamor_poly_lines_dash_gl(DrawablePtr drawable, GCPtr gc,
241                          int mode, int n, DDXPointPtr points)
242{
243    ScreenPtr screen = drawable->pScreen;
244    glamor_program *prog;
245    short *v;
246    char *vbo_offset;
247    int add_last;
248    int dash_pos;
249    int prev_x, prev_y;
250    int i;
251
252    if (n < 2)
253        return TRUE;
254
255    if (!(prog = glamor_dash_setup(drawable, gc)))
256        return FALSE;
257
258    add_last = 0;
259    if (gc->capStyle != CapNotLast)
260        add_last = 1;
261
262    /* Set up the vertex buffers for the points */
263
264    v = glamor_get_vbo_space(drawable->pScreen,
265                             (n + add_last) * 3 * sizeof (short),
266                             &vbo_offset);
267
268    glEnableVertexAttribArray(GLAMOR_VERTEX_POS);
269    glVertexAttribPointer(GLAMOR_VERTEX_POS, 3, GL_SHORT, GL_FALSE,
270                          3 * sizeof (short), vbo_offset);
271
272    dash_pos = gc->dashOffset;
273    prev_x = prev_y = 0;
274    for (i = 0; i < n; i++) {
275        int this_x = points[i].x;
276        int this_y = points[i].y;
277        if (i) {
278            if (mode == CoordModePrevious) {
279                this_x += prev_x;
280                this_y += prev_y;
281            }
282            dash_pos += glamor_line_length(prev_x, prev_y,
283                                           this_x, this_y);
284        }
285        v[0] = prev_x = this_x;
286        v[1] = prev_y = this_y;
287        v[2] = dash_pos;
288        v += 3;
289    }
290
291    if (add_last) {
292        v[0] = prev_x + 1;
293        v[1] = prev_y;
294        v[2] = dash_pos + 1;
295    }
296
297    glamor_put_vbo_space(screen);
298
299    glamor_dash_loop(drawable, gc, prog, n + add_last, GL_LINE_STRIP);
300
301    return TRUE;
302}
303
304static short *
305glamor_add_segment(short *v, short x1, short y1, short x2, short y2,
306                   int dash_start, int dash_end)
307{
308    v[0] = x1;
309    v[1] = y1;
310    v[2] = dash_start;
311
312    v[3] = x2;
313    v[4] = y2;
314    v[5] = dash_end;
315    return v + 6;
316}
317
318Bool
319glamor_poly_segment_dash_gl(DrawablePtr drawable, GCPtr gc,
320                            int nseg, xSegment *segs)
321{
322    ScreenPtr screen = drawable->pScreen;
323    glamor_program *prog;
324    short *v;
325    char *vbo_offset;
326    int dash_start = gc->dashOffset;
327    int add_last;
328    int i;
329
330    if (!(prog = glamor_dash_setup(drawable, gc)))
331        return FALSE;
332
333    add_last = 0;
334    if (gc->capStyle != CapNotLast)
335        add_last = 1;
336
337    /* Set up the vertex buffers for the points */
338
339    v = glamor_get_vbo_space(drawable->pScreen,
340                             (nseg<<add_last) * 6 * sizeof (short),
341                             &vbo_offset);
342
343    glEnableVertexAttribArray(GLAMOR_VERTEX_POS);
344    glVertexAttribPointer(GLAMOR_VERTEX_POS, 3, GL_SHORT, GL_FALSE,
345                          3 * sizeof (short), vbo_offset);
346
347    for (i = 0; i < nseg; i++) {
348        int dash_end = dash_start + glamor_line_length(segs[i].x1, segs[i].y1,
349                                                       segs[i].x2, segs[i].y2);
350        v = glamor_add_segment(v,
351                               segs[i].x1, segs[i].y1,
352                               segs[i].x2, segs[i].y2,
353                               dash_start, dash_end);
354        if (add_last)
355            v = glamor_add_segment(v,
356                                   segs[i].x2, segs[i].y2,
357                                   segs[i].x2 + 1, segs[i].y2,
358                                   dash_end, dash_end + 1);
359    }
360
361    glamor_put_vbo_space(screen);
362
363    glamor_dash_loop(drawable, gc, prog, nseg << (1 + add_last), GL_LINES);
364
365    return TRUE;
366}
367