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/arrayobj.h"
42#include "main/feedback.h"
43#include "main/rastpos.h"
44#include "main/state.h"
45#include "main/varray.h"
46
47#include "st_context.h"
48#include "st_atom.h"
49#include "st_draw.h"
50#include "st_program.h"
51#include "st_cb_rasterpos.h"
52#include "st_util.h"
53#include "draw/draw_context.h"
54#include "draw/draw_pipe.h"
55#include "vbo/vbo.h"
56
57
58/**
59 * Our special drawing pipeline stage (replaces rasterization).
60 */
61struct rastpos_stage
62{
63   struct draw_stage stage;   /**< Base class */
64   struct gl_context *ctx;            /**< Rendering context */
65
66   /* vertex attrib info we can setup once and re-use */
67   struct gl_vertex_array_object *VAO;
68   struct _mesa_prim prim;
69};
70
71
72static inline struct rastpos_stage *
73rastpos_stage( struct draw_stage *stage )
74{
75   return (struct rastpos_stage *) stage;
76}
77
78static void
79rastpos_flush( struct draw_stage *stage, unsigned flags )
80{
81   /* no-op */
82}
83
84static void
85rastpos_reset_stipple_counter( struct draw_stage *stage )
86{
87   /* no-op */
88}
89
90static void
91rastpos_tri( struct draw_stage *stage, struct prim_header *prim )
92{
93   /* should never get here */
94   assert(0);
95}
96
97static void
98rastpos_line( struct draw_stage *stage, struct prim_header *prim )
99{
100   /* should never get here */
101   assert(0);
102}
103
104static void
105rastpos_destroy(struct draw_stage *stage)
106{
107   struct rastpos_stage *rstage = (struct rastpos_stage*)stage;
108   _mesa_reference_vao(rstage->ctx, &rstage->VAO, NULL);
109   free(stage);
110}
111
112
113/**
114 * Update a raster pos attribute from the vertex result if it's present,
115 * else copy the current attrib.
116 */
117static void
118update_attrib(struct gl_context *ctx, const ubyte *outputMapping,
119              const struct vertex_header *vert,
120              GLfloat *dest,
121              GLuint result, GLuint defaultAttrib)
122{
123   const GLfloat *src;
124   const GLuint k = outputMapping[result];
125   if (k != ~0U)
126      src = vert->data[k];
127   else
128      src = ctx->Current.Attrib[defaultAttrib];
129   COPY_4V(dest, src);
130}
131
132
133/**
134 * Normally, this function would render a GL_POINT.
135 */
136static void
137rastpos_point(struct draw_stage *stage, struct prim_header *prim)
138{
139   struct rastpos_stage *rs = rastpos_stage(stage);
140   struct gl_context *ctx = rs->ctx;
141   struct st_context *st = st_context(ctx);
142   const GLfloat height = (GLfloat) ctx->DrawBuffer->Height;
143   const ubyte *outputMapping = st->vp->result_to_output;
144   const GLfloat *pos;
145   GLuint i;
146
147   /* if we get here, we didn't get clipped */
148   ctx->Current.RasterPosValid = GL_TRUE;
149
150   /* update raster pos */
151   pos = prim->v[0]->data[0];
152   ctx->Current.RasterPos[0] = pos[0];
153   if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
154      ctx->Current.RasterPos[1] = height - pos[1]; /* invert Y */
155   else
156      ctx->Current.RasterPos[1] = pos[1];
157   ctx->Current.RasterPos[2] = pos[2];
158   ctx->Current.RasterPos[3] = pos[3];
159
160   /* update other raster attribs */
161   update_attrib(ctx, outputMapping, prim->v[0],
162                 ctx->Current.RasterColor,
163                 VARYING_SLOT_COL0, VERT_ATTRIB_COLOR0);
164
165   update_attrib(ctx, outputMapping, prim->v[0],
166                 ctx->Current.RasterSecondaryColor,
167                 VARYING_SLOT_COL1, VERT_ATTRIB_COLOR1);
168
169   for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
170      update_attrib(ctx, outputMapping, prim->v[0],
171                    ctx->Current.RasterTexCoords[i],
172                    VARYING_SLOT_TEX0 + i, VERT_ATTRIB_TEX0 + i);
173   }
174
175   if (ctx->RenderMode == GL_SELECT) {
176      _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
177   }
178}
179
180
181/**
182 * Create rasterpos "drawing" stage.
183 */
184static struct rastpos_stage *
185new_draw_rastpos_stage(struct gl_context *ctx, struct draw_context *draw)
186{
187   struct rastpos_stage *rs = ST_CALLOC_STRUCT(rastpos_stage);
188
189   rs->stage.draw = draw;
190   rs->stage.next = NULL;
191   rs->stage.point = rastpos_point;
192   rs->stage.line = rastpos_line;
193   rs->stage.tri = rastpos_tri;
194   rs->stage.flush = rastpos_flush;
195   rs->stage.destroy = rastpos_destroy;
196   rs->stage.reset_stipple_counter = rastpos_reset_stipple_counter;
197   rs->stage.destroy = rastpos_destroy;
198   rs->ctx = ctx;
199
200   rs->VAO = _mesa_new_vao(ctx, ~((GLuint)0));
201   _mesa_vertex_attrib_binding(ctx, rs->VAO, VERT_ATTRIB_POS, 0);
202   _mesa_update_array_format(ctx, rs->VAO, VERT_ATTRIB_POS, 4, GL_FLOAT,
203                             GL_RGBA, GL_FALSE, GL_FALSE, GL_FALSE, 0);
204   _mesa_enable_vertex_array_attrib(ctx, rs->VAO, 0);
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.start = 0;
211   rs->prim.count = 1;
212   rs->prim.pad = 0;
213   rs->prim.num_instances = 1;
214   rs->prim.base_instance = 0;
215   rs->prim.is_indirect = 0;
216
217   return rs;
218}
219
220
221static void
222st_RasterPos(struct gl_context *ctx, const GLfloat v[4])
223{
224   struct st_context *st = st_context(ctx);
225   struct draw_context *draw = st_get_draw_context(st);
226   struct rastpos_stage *rs;
227
228   if (!st->draw)
229      return;
230
231   if (ctx->VertexProgram._Current == NULL ||
232       ctx->VertexProgram._Current == ctx->VertexProgram._TnlProgram) {
233      /* No vertex shader/program is enabled, used the simple/fast fixed-
234       * function implementation of RasterPos.
235       */
236      _mesa_RasterPos(ctx, v);
237      return;
238   }
239
240   if (st->rastpos_stage) {
241      /* get rastpos stage info */
242      rs = rastpos_stage(st->rastpos_stage);
243   }
244   else {
245      /* create rastpos draw stage */
246      rs = new_draw_rastpos_stage(ctx, draw);
247      st->rastpos_stage = &rs->stage;
248   }
249
250   /* plug our rastpos stage into the draw module */
251   draw_set_rasterize_stage(st->draw, st->rastpos_stage);
252
253   /* make sure everything's up to date */
254   st_validate_state(st, ST_PIPELINE_RENDER);
255
256   /* This will get set only if rastpos_point(), above, gets called */
257   ctx->Current.RasterPosValid = GL_FALSE;
258
259   /* All vertex attribs but position were previously initialized above.
260    * Just plug in position pointer now.
261    */
262   rs->VAO->VertexAttrib[VERT_ATTRIB_POS].Ptr = (GLubyte *) v;
263   rs->VAO->NewArrays |= VERT_BIT_POS;
264   _mesa_set_draw_vao(ctx, rs->VAO, VERT_BIT_POS);
265
266   /* Draw the point. */
267   st_feedback_draw_vbo(ctx, &rs->prim, 1, NULL, GL_TRUE, 0, 1,
268                        NULL, 0, NULL);
269
270   /* restore draw's rasterization stage depending on rendermode */
271   if (ctx->RenderMode == GL_FEEDBACK) {
272      draw_set_rasterize_stage(draw, st->feedback_stage);
273   }
274   else if (ctx->RenderMode == GL_SELECT) {
275      draw_set_rasterize_stage(draw, st->selection_stage);
276   }
277}
278
279
280
281void st_init_rasterpos_functions(struct dd_function_table *functions)
282{
283   functions->RasterPos = st_RasterPos;
284}
285