1 /*
2 * Mesa 3-D graphics library
3 * Version: 7.1
4 *
5 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
23 */
24
25
26 /*
27 * Antialiased line template.
28 */
29
30
31 /*
32 * Function to render each fragment in the AA line.
33 * \param ix - integer fragment window X coordiante
34 * \param iy - integer fragment window Y coordiante
35 */
36 static void
NAME(plot)37 NAME(plot)(struct gl_context *ctx, struct LineInfo *line, int ix, int iy)
38 {
39 const SWcontext *swrast = SWRAST_CONTEXT(ctx);
40 const GLfloat fx = (GLfloat) ix;
41 const GLfloat fy = (GLfloat) iy;
42 const GLfloat coverage = compute_coveragef(line, ix, iy);
43 const GLuint i = line->span.end;
44
45 (void) swrast;
46
47 if (coverage == 0.0)
48 return;
49
50 line->span.end++;
51 line->span.array->coverage[i] = coverage;
52 line->span.array->x[i] = ix;
53 line->span.array->y[i] = iy;
54
55 /*
56 * Compute Z, color, texture coords, fog for the fragment by
57 * solving the plane equations at (ix,iy).
58 */
59 #ifdef DO_Z
60 line->span.array->z[i] = (GLuint) solve_plane(fx, fy, line->zPlane);
61 #endif
62 line->span.array->rgba[i][RCOMP] = solve_plane_chan(fx, fy, line->rPlane);
63 line->span.array->rgba[i][GCOMP] = solve_plane_chan(fx, fy, line->gPlane);
64 line->span.array->rgba[i][BCOMP] = solve_plane_chan(fx, fy, line->bPlane);
65 line->span.array->rgba[i][ACOMP] = solve_plane_chan(fx, fy, line->aPlane);
66 #if defined(DO_ATTRIBS)
67 ATTRIB_LOOP_BEGIN
68 GLfloat (*attribArray)[4] = line->span.array->attribs[attr];
69 if (attr >= FRAG_ATTRIB_TEX0 && attr < FRAG_ATTRIB_VAR0
70 && !_swrast_use_fragment_program(ctx)) {
71 /* texcoord w/ divide by Q */
72 const GLuint unit = attr - FRAG_ATTRIB_TEX0;
73 const GLfloat invQ = solve_plane_recip(fx, fy, line->attrPlane[attr][3]);
74 GLuint c;
75 for (c = 0; c < 3; c++) {
76 attribArray[i][c] = solve_plane(fx, fy, line->attrPlane[attr][c]) * invQ;
77 }
78 line->span.array->lambda[unit][i]
79 = compute_lambda(line->attrPlane[attr][0],
80 line->attrPlane[attr][1], invQ,
81 line->texWidth[attr], line->texHeight[attr]);
82 }
83 else {
84 /* non-texture attrib */
85 const GLfloat invW = solve_plane_recip(fx, fy, line->wPlane);
86 GLuint c;
87 for (c = 0; c < 4; c++) {
88 attribArray[i][c] = solve_plane(fx, fy, line->attrPlane[attr][c]) * invW;
89 }
90 }
91 ATTRIB_LOOP_END
92 #endif
93
94 if (line->span.end == SWRAST_MAX_WIDTH) {
95 _swrast_write_rgba_span(ctx, &(line->span));
96 line->span.end = 0; /* reset counter */
97 }
98 }
99
100
101
102 /*
103 * Line setup
104 */
105 static void
NAME(line)106 NAME(line)(struct gl_context *ctx, const SWvertex *v0, const SWvertex *v1)
107 {
108 SWcontext *swrast = SWRAST_CONTEXT(ctx);
109 GLfloat tStart, tEnd; /* segment start, end along line length */
110 GLboolean inSegment;
111 GLint iLen, i;
112
113 /* Init the LineInfo struct */
114 struct LineInfo line;
115 line.x0 = v0->attrib[FRAG_ATTRIB_WPOS][0];
116 line.y0 = v0->attrib[FRAG_ATTRIB_WPOS][1];
117 line.x1 = v1->attrib[FRAG_ATTRIB_WPOS][0];
118 line.y1 = v1->attrib[FRAG_ATTRIB_WPOS][1];
119 line.dx = line.x1 - line.x0;
120 line.dy = line.y1 - line.y0;
121 line.len = SQRTF(line.dx * line.dx + line.dy * line.dy);
122 line.halfWidth = 0.5F * CLAMP(ctx->Line.Width,
123 ctx->Const.MinLineWidthAA,
124 ctx->Const.MaxLineWidthAA);
125
126 if (line.len == 0.0 || IS_INF_OR_NAN(line.len))
127 return;
128
129 INIT_SPAN(line.span, GL_LINE);
130 line.span.arrayMask = SPAN_XY | SPAN_COVERAGE;
131 line.span.facing = swrast->PointLineFacing;
132 line.xAdj = line.dx / line.len * line.halfWidth;
133 line.yAdj = line.dy / line.len * line.halfWidth;
134
135 #ifdef DO_Z
136 line.span.arrayMask |= SPAN_Z;
137 compute_plane(line.x0, line.y0, line.x1, line.y1,
138 v0->attrib[FRAG_ATTRIB_WPOS][2], v1->attrib[FRAG_ATTRIB_WPOS][2], line.zPlane);
139 #endif
140 line.span.arrayMask |= SPAN_RGBA;
141 if (ctx->Light.ShadeModel == GL_SMOOTH) {
142 compute_plane(line.x0, line.y0, line.x1, line.y1,
143 v0->color[RCOMP], v1->color[RCOMP], line.rPlane);
144 compute_plane(line.x0, line.y0, line.x1, line.y1,
145 v0->color[GCOMP], v1->color[GCOMP], line.gPlane);
146 compute_plane(line.x0, line.y0, line.x1, line.y1,
147 v0->color[BCOMP], v1->color[BCOMP], line.bPlane);
148 compute_plane(line.x0, line.y0, line.x1, line.y1,
149 v0->color[ACOMP], v1->color[ACOMP], line.aPlane);
150 }
151 else {
152 constant_plane(v1->color[RCOMP], line.rPlane);
153 constant_plane(v1->color[GCOMP], line.gPlane);
154 constant_plane(v1->color[BCOMP], line.bPlane);
155 constant_plane(v1->color[ACOMP], line.aPlane);
156 }
157 #if defined(DO_ATTRIBS)
158 {
159 const GLfloat invW0 = v0->attrib[FRAG_ATTRIB_WPOS][3];
160 const GLfloat invW1 = v1->attrib[FRAG_ATTRIB_WPOS][3];
161 line.span.arrayMask |= SPAN_LAMBDA;
162 compute_plane(line.x0, line.y0, line.x1, line.y1, invW0, invW1, line.wPlane);
163 ATTRIB_LOOP_BEGIN
164 GLuint c;
165 if (swrast->_InterpMode[attr] == GL_FLAT) {
166 for (c = 0; c < 4; c++) {
167 constant_plane(v1->attrib[attr][c], line.attrPlane[attr][c]);
168 }
169 }
170 else {
171 for (c = 0; c < 4; c++) {
172 const GLfloat a0 = v0->attrib[attr][c] * invW0;
173 const GLfloat a1 = v1->attrib[attr][c] * invW1;
174 compute_plane(line.x0, line.y0, line.x1, line.y1, a0, a1,
175 line.attrPlane[attr][c]);
176 }
177 }
178 line.span.arrayAttribs |= BITFIELD64_BIT(attr);
179 if (attr >= FRAG_ATTRIB_TEX0 && attr < FRAG_ATTRIB_VAR0) {
180 const GLuint u = attr - FRAG_ATTRIB_TEX0;
181 const struct gl_texture_object *obj = ctx->Texture.Unit[u]._Current;
182 const struct gl_texture_image *texImage = obj->Image[0][obj->BaseLevel];
183 line.texWidth[attr] = (GLfloat) texImage->Width;
184 line.texHeight[attr] = (GLfloat) texImage->Height;
185 }
186 ATTRIB_LOOP_END
187 }
188 #endif
189
190 tStart = tEnd = 0.0;
191 inSegment = GL_FALSE;
192 iLen = (GLint) line.len;
193
194 if (ctx->Line.StippleFlag) {
195 for (i = 0; i < iLen; i++) {
196 const GLuint bit = (swrast->StippleCounter / ctx->Line.StippleFactor) & 0xf;
197 if ((1 << bit) & ctx->Line.StipplePattern) {
198 /* stipple bit is on */
199 const GLfloat t = (GLfloat) i / (GLfloat) line.len;
200 if (!inSegment) {
201 /* start new segment */
202 inSegment = GL_TRUE;
203 tStart = t;
204 }
205 else {
206 /* still in the segment, extend it */
207 tEnd = t;
208 }
209 }
210 else {
211 /* stipple bit is off */
212 if (inSegment && (tEnd > tStart)) {
213 /* draw the segment */
214 segment(ctx, &line, NAME(plot), tStart, tEnd);
215 inSegment = GL_FALSE;
216 }
217 else {
218 /* still between segments, do nothing */
219 }
220 }
221 swrast->StippleCounter++;
222 }
223
224 if (inSegment) {
225 /* draw the final segment of the line */
226 segment(ctx, &line, NAME(plot), tStart, 1.0F);
227 }
228 }
229 else {
230 /* non-stippled */
231 segment(ctx, &line, NAME(plot), 0.0, 1.0);
232 }
233
234 _swrast_write_rgba_span(ctx, &(line.span));
235 }
236
237
238
239
240 #undef DO_Z
241 #undef DO_ATTRIBS
242 #undef NAME
243