1 /**************************************************************************
2  *
3  * Copyright 2007 VMware, Inc.
4  * All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sub license, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
26  **************************************************************************/
27 
28 /**
29  * glRasterPos implementation.  Basically render a GL_POINT with our
30  * private draw module.  Plug in a special "rasterpos" stage at the end
31  * of the 'draw' pipeline to capture the results and update the current
32  * raster pos attributes.
33  *
34  * Authors:
35  *   Brian Paul
36  */
37 
38 
39 #include "main/imports.h"
40 #include "main/macros.h"
41 #include "main/feedback.h"
42 #include "main/rastpos.h"
43 
44 #include "st_context.h"
45 #include "st_atom.h"
46 #include "st_draw.h"
47 #include "st_cb_rasterpos.h"
48 #include "draw/draw_context.h"
49 #include "draw/draw_pipe.h"
50 #include "vbo/vbo.h"
51 
52 
53 /**
54  * Our special drawing pipeline stage (replaces rasterization).
55  */
56 struct rastpos_stage
57 {
58    struct draw_stage stage;   /**< Base class */
59    struct gl_context *ctx;            /**< Rendering context */
60 
61    /* vertex attrib info we can setup once and re-use */
62    struct gl_vertex_array array[VERT_ATTRIB_MAX];
63    const struct gl_vertex_array *arrays[VERT_ATTRIB_MAX];
64    struct _mesa_prim prim;
65 };
66 
67 
68 static inline struct rastpos_stage *
rastpos_stage(struct draw_stage * stage)69 rastpos_stage( struct draw_stage *stage )
70 {
71    return (struct rastpos_stage *) stage;
72 }
73 
74 static void
rastpos_flush(struct draw_stage * stage,unsigned flags)75 rastpos_flush( struct draw_stage *stage, unsigned flags )
76 {
77    /* no-op */
78 }
79 
80 static void
rastpos_reset_stipple_counter(struct draw_stage * stage)81 rastpos_reset_stipple_counter( struct draw_stage *stage )
82 {
83    /* no-op */
84 }
85 
86 static void
rastpos_tri(struct draw_stage * stage,struct prim_header * prim)87 rastpos_tri( struct draw_stage *stage, struct prim_header *prim )
88 {
89    /* should never get here */
90    assert(0);
91 }
92 
93 static void
rastpos_line(struct draw_stage * stage,struct prim_header * prim)94 rastpos_line( struct draw_stage *stage, struct prim_header *prim )
95 {
96    /* should never get here */
97    assert(0);
98 }
99 
100 static void
rastpos_destroy(struct draw_stage * stage)101 rastpos_destroy(struct draw_stage *stage)
102 {
103    free(stage);
104 }
105 
106 
107 /**
108  * Update a raster pos attribute from the vertex result if it's present,
109  * else copy the current attrib.
110  */
111 static void
update_attrib(struct gl_context * ctx,const GLuint * outputMapping,const struct vertex_header * vert,GLfloat * dest,GLuint result,GLuint defaultAttrib)112 update_attrib(struct gl_context *ctx, const GLuint *outputMapping,
113               const struct vertex_header *vert,
114               GLfloat *dest,
115               GLuint result, GLuint defaultAttrib)
116 {
117    const GLfloat *src;
118    const GLuint k = outputMapping[result];
119    if (k != ~0U)
120       src = vert->data[k];
121    else
122       src = ctx->Current.Attrib[defaultAttrib];
123    COPY_4V(dest, src);
124 }
125 
126 
127 /**
128  * Normally, this function would render a GL_POINT.
129  */
130 static void
rastpos_point(struct draw_stage * stage,struct prim_header * prim)131 rastpos_point(struct draw_stage *stage, struct prim_header *prim)
132 {
133    struct rastpos_stage *rs = rastpos_stage(stage);
134    struct gl_context *ctx = rs->ctx;
135    struct st_context *st = st_context(ctx);
136    const GLfloat height = (GLfloat) ctx->DrawBuffer->Height;
137    const GLuint *outputMapping = st->vertex_result_to_slot;
138    const GLfloat *pos;
139    GLuint i;
140 
141    /* if we get here, we didn't get clipped */
142    ctx->Current.RasterPosValid = GL_TRUE;
143 
144    /* update raster pos */
145    pos = prim->v[0]->data[0];
146    ctx->Current.RasterPos[0] = pos[0];
147    if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
148       ctx->Current.RasterPos[1] = height - pos[1]; /* invert Y */
149    else
150       ctx->Current.RasterPos[1] = pos[1];
151    ctx->Current.RasterPos[2] = pos[2];
152    ctx->Current.RasterPos[3] = pos[3];
153 
154    /* update other raster attribs */
155    update_attrib(ctx, outputMapping, prim->v[0],
156                  ctx->Current.RasterColor,
157                  VARYING_SLOT_COL0, VERT_ATTRIB_COLOR0);
158 
159    update_attrib(ctx, outputMapping, prim->v[0],
160                  ctx->Current.RasterSecondaryColor,
161                  VARYING_SLOT_COL1, VERT_ATTRIB_COLOR1);
162 
163    for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
164       update_attrib(ctx, outputMapping, prim->v[0],
165                     ctx->Current.RasterTexCoords[i],
166                     VARYING_SLOT_TEX0 + i, VERT_ATTRIB_TEX0 + i);
167    }
168 
169    if (ctx->RenderMode == GL_SELECT) {
170       _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
171    }
172 }
173 
174 
175 /**
176  * Create rasterpos "drawing" stage.
177  */
178 static struct rastpos_stage *
new_draw_rastpos_stage(struct gl_context * ctx,struct draw_context * draw)179 new_draw_rastpos_stage(struct gl_context *ctx, struct draw_context *draw)
180 {
181    struct rastpos_stage *rs = ST_CALLOC_STRUCT(rastpos_stage);
182    GLuint i;
183 
184    rs->stage.draw = draw;
185    rs->stage.next = NULL;
186    rs->stage.point = rastpos_point;
187    rs->stage.line = rastpos_line;
188    rs->stage.tri = rastpos_tri;
189    rs->stage.flush = rastpos_flush;
190    rs->stage.destroy = rastpos_destroy;
191    rs->stage.reset_stipple_counter = rastpos_reset_stipple_counter;
192    rs->stage.destroy = rastpos_destroy;
193    rs->ctx = ctx;
194 
195    for (i = 0; i < ARRAY_SIZE(rs->array); i++) {
196       rs->array[i].Size = 4;
197       rs->array[i].Type = GL_FLOAT;
198       rs->array[i].Format = GL_RGBA;
199       rs->array[i].StrideB = 0;
200       rs->array[i].Ptr = (GLubyte *) ctx->Current.Attrib[i];
201       rs->array[i].Normalized = GL_TRUE;
202       rs->array[i].BufferObj = NULL;
203       rs->arrays[i] = &rs->array[i];
204    }
205 
206    rs->prim.mode = GL_POINTS;
207    rs->prim.indexed = 0;
208    rs->prim.begin = 1;
209    rs->prim.end = 1;
210    rs->prim.weak = 0;
211    rs->prim.start = 0;
212    rs->prim.count = 1;
213 
214    return rs;
215 }
216 
217 
218 static void
st_RasterPos(struct gl_context * ctx,const GLfloat v[4])219 st_RasterPos(struct gl_context *ctx, const GLfloat v[4])
220 {
221    struct st_context *st = st_context(ctx);
222    struct draw_context *draw = st_get_draw_context(st);
223    struct rastpos_stage *rs;
224    const struct gl_vertex_array **saved_arrays = ctx->Array._DrawArrays;
225 
226    if (!st->draw)
227       return;
228 
229    if (ctx->VertexProgram._Current == NULL ||
230        ctx->VertexProgram._Current == ctx->VertexProgram._TnlProgram) {
231       /* No vertex shader/program is enabled, used the simple/fast fixed-
232        * function implementation of RasterPos.
233        */
234       _mesa_RasterPos(ctx, v);
235       return;
236    }
237 
238    if (st->rastpos_stage) {
239       /* get rastpos stage info */
240       rs = rastpos_stage(st->rastpos_stage);
241    }
242    else {
243       /* create rastpos draw stage */
244       rs = new_draw_rastpos_stage(ctx, draw);
245       st->rastpos_stage = &rs->stage;
246    }
247 
248    /* plug our rastpos stage into the draw module */
249    draw_set_rasterize_stage(st->draw, st->rastpos_stage);
250 
251    /* make sure everything's up to date */
252    st_validate_state(st, ST_PIPELINE_RENDER);
253 
254    /* This will get set only if rastpos_point(), above, gets called */
255    ctx->Current.RasterPosValid = GL_FALSE;
256 
257    /* All vertex attribs but position were previously initialized above.
258     * Just plug in position pointer now.
259     */
260    rs->array[0].Ptr = (GLubyte *) v;
261 
262    /* Draw the point.
263     *
264     * Don't set DriverFlags.NewArray.
265     * st_feedback_draw_vbo doesn't check for that flag. */
266    ctx->Array._DrawArrays = rs->arrays;
267    st_feedback_draw_vbo(ctx, &rs->prim, 1, NULL, GL_TRUE, 0, 1,
268                         NULL, 0, NULL);
269    ctx->Array._DrawArrays = saved_arrays;
270 
271    /* restore draw's rasterization stage depending on rendermode */
272    if (ctx->RenderMode == GL_FEEDBACK) {
273       draw_set_rasterize_stage(draw, st->feedback_stage);
274    }
275    else if (ctx->RenderMode == GL_SELECT) {
276       draw_set_rasterize_stage(draw, st->selection_stage);
277    }
278 }
279 
280 
281 
st_init_rasterpos_functions(struct dd_function_table * functions)282 void st_init_rasterpos_functions(struct dd_function_table *functions)
283 {
284    functions->RasterPos = st_RasterPos;
285 }
286