1/**************************************************************************
2 *
3 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
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 TUNGSTEN GRAPHICS 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/mfeatures.h"
42#include "main/feedback.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#if FEATURE_rastpos
54
55/**
56 * Our special drawing pipeline stage (replaces rasterization).
57 */
58struct rastpos_stage
59{
60   struct draw_stage stage;   /**< Base class */
61   struct gl_context *ctx;            /**< Rendering context */
62
63   /* vertex attrib info we can setup once and re-use */
64   struct gl_client_array array[VERT_ATTRIB_MAX];
65   const struct gl_client_array *arrays[VERT_ATTRIB_MAX];
66   struct _mesa_prim prim;
67};
68
69
70static INLINE struct rastpos_stage *
71rastpos_stage( struct draw_stage *stage )
72{
73   return (struct rastpos_stage *) stage;
74}
75
76static void
77rastpos_flush( struct draw_stage *stage, unsigned flags )
78{
79   /* no-op */
80}
81
82static void
83rastpos_reset_stipple_counter( struct draw_stage *stage )
84{
85   /* no-op */
86}
87
88static void
89rastpos_tri( struct draw_stage *stage, struct prim_header *prim )
90{
91   /* should never get here */
92   assert(0);
93}
94
95static void
96rastpos_line( struct draw_stage *stage, struct prim_header *prim )
97{
98   /* should never get here */
99   assert(0);
100}
101
102static void
103rastpos_destroy(struct draw_stage *stage)
104{
105   free(stage);
106}
107
108
109/**
110 * Update a raster pos attribute from the vertex result if it's present,
111 * else copy the current attrib.
112 */
113static void
114update_attrib(struct gl_context *ctx, const GLuint *outputMapping,
115              const struct vertex_header *vert,
116              GLfloat *dest,
117              GLuint result, GLuint defaultAttrib)
118{
119   const GLfloat *src;
120   const GLuint k = outputMapping[result];
121   if (k != ~0U)
122      src = vert->data[k];
123   else
124      src = ctx->Current.Attrib[defaultAttrib];
125   COPY_4V(dest, src);
126}
127
128
129/**
130 * Normally, this function would render a GL_POINT.
131 */
132static void
133rastpos_point(struct draw_stage *stage, struct prim_header *prim)
134{
135   struct rastpos_stage *rs = rastpos_stage(stage);
136   struct gl_context *ctx = rs->ctx;
137   struct st_context *st = st_context(ctx);
138   const GLfloat height = (GLfloat) ctx->DrawBuffer->Height;
139   const GLuint *outputMapping = st->vertex_result_to_slot;
140   const GLfloat *pos;
141   GLuint i;
142
143   /* if we get here, we didn't get clipped */
144   ctx->Current.RasterPosValid = GL_TRUE;
145
146   /* update raster pos */
147   pos = prim->v[0]->data[0];
148   ctx->Current.RasterPos[0] = pos[0];
149   if (st_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
150      ctx->Current.RasterPos[1] = height - pos[1]; /* invert Y */
151   else
152      ctx->Current.RasterPos[1] = pos[1];
153   ctx->Current.RasterPos[2] = pos[2];
154   ctx->Current.RasterPos[3] = pos[3];
155
156   /* update other raster attribs */
157   update_attrib(ctx, outputMapping, prim->v[0],
158                 ctx->Current.RasterColor,
159                 VERT_RESULT_COL0, VERT_ATTRIB_COLOR0);
160
161   update_attrib(ctx, outputMapping, prim->v[0],
162                 ctx->Current.RasterSecondaryColor,
163                 VERT_RESULT_COL1, VERT_ATTRIB_COLOR1);
164
165   for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
166      update_attrib(ctx, outputMapping, prim->v[0],
167                    ctx->Current.RasterTexCoords[i],
168                    VERT_RESULT_TEX0 + i, VERT_ATTRIB_TEX0 + i);
169   }
170
171   if (ctx->RenderMode == GL_SELECT) {
172      _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
173   }
174}
175
176
177/**
178 * Create rasterpos "drawing" stage.
179 */
180static struct rastpos_stage *
181new_draw_rastpos_stage(struct gl_context *ctx, struct draw_context *draw)
182{
183   struct rastpos_stage *rs = ST_CALLOC_STRUCT(rastpos_stage);
184   GLuint i;
185
186   rs->stage.draw = draw;
187   rs->stage.next = NULL;
188   rs->stage.point = rastpos_point;
189   rs->stage.line = rastpos_line;
190   rs->stage.tri = rastpos_tri;
191   rs->stage.flush = rastpos_flush;
192   rs->stage.destroy = rastpos_destroy;
193   rs->stage.reset_stipple_counter = rastpos_reset_stipple_counter;
194   rs->stage.destroy = rastpos_destroy;
195   rs->ctx = ctx;
196
197   for (i = 0; i < Elements(rs->array); i++) {
198      rs->array[i].Size = 4;
199      rs->array[i].Type = GL_FLOAT;
200      rs->array[i].Format = GL_RGBA;
201      rs->array[i].Stride = 0;
202      rs->array[i].StrideB = 0;
203      rs->array[i].Ptr = (GLubyte *) ctx->Current.Attrib[i];
204      rs->array[i].Enabled = GL_TRUE;
205      rs->array[i].Normalized = GL_TRUE;
206      rs->array[i].BufferObj = NULL;
207      rs->arrays[i] = &rs->array[i];
208   }
209
210   rs->prim.mode = GL_POINTS;
211   rs->prim.indexed = 0;
212   rs->prim.begin = 1;
213   rs->prim.end = 1;
214   rs->prim.weak = 0;
215   rs->prim.start = 0;
216   rs->prim.count = 1;
217
218   return rs;
219}
220
221
222static void
223st_RasterPos(struct gl_context *ctx, const GLfloat v[4])
224{
225   struct st_context *st = st_context(ctx);
226   struct draw_context *draw = st->draw;
227   struct rastpos_stage *rs;
228   const struct gl_client_array **saved_arrays = ctx->Array._DrawArrays;
229
230   if (st->rastpos_stage) {
231      /* get rastpos stage info */
232      rs = rastpos_stage(st->rastpos_stage);
233   }
234   else {
235      /* create rastpos draw stage */
236      rs = new_draw_rastpos_stage(ctx, draw);
237      st->rastpos_stage = &rs->stage;
238   }
239
240   /* plug our rastpos stage into the draw module */
241   draw_set_rasterize_stage(st->draw, st->rastpos_stage);
242
243   /* make sure everything's up to date */
244   st_validate_state(st);
245
246   /* This will get set only if rastpos_point(), above, gets called */
247   ctx->Current.RasterPosValid = GL_FALSE;
248
249   /* All vertex attribs but position were previously initialized above.
250    * Just plug in position pointer now.
251    */
252   rs->array[0].Ptr = (GLubyte *) v;
253
254   /* Draw the point.
255    *
256    * Don't set DriverFlags.NewArray.
257    * st_feedback_draw_vbo doesn't check for that flag. */
258   ctx->Array._DrawArrays = rs->arrays;
259   st_feedback_draw_vbo(ctx, &rs->prim, 1, NULL, GL_TRUE, 0, 1,
260                        NULL);
261   ctx->Array._DrawArrays = saved_arrays;
262
263   /* restore draw's rasterization stage depending on rendermode */
264   if (ctx->RenderMode == GL_FEEDBACK) {
265      draw_set_rasterize_stage(draw, st->feedback_stage);
266   }
267   else if (ctx->RenderMode == GL_SELECT) {
268      draw_set_rasterize_stage(draw, st->selection_stage);
269   }
270}
271
272
273
274void st_init_rasterpos_functions(struct dd_function_table *functions)
275{
276   functions->RasterPos = st_RasterPos;
277}
278
279#endif /* FEATURE_rastpos */
280