xref: /aosp_15_r20/external/mesa3d/src/mesa/state_tracker/st_cb_rasterpos.c (revision 6104692788411f58d303aa86923a9ff6ecaded22)
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2  *
3  * Copyright 2007 VMware, Inc.
4  * All Rights Reserved.
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6  * Permission is hereby granted, free of charge, to any person obtaining a
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11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
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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.
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18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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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 
40 #include "main/macros.h"
41 #include "main/arrayobj.h"
42 #include "main/feedback.h"
43 #include "main/framebuffer.h"
44 #include "main/rastpos.h"
45 #include "main/state.h"
46 #include "main/varray.h"
47 
48 #include "util/u_memory.h"
49 
50 #include "st_context.h"
51 #include "st_atom.h"
52 #include "st_draw.h"
53 #include "st_program.h"
54 #include "st_cb_rasterpos.h"
55 #include "st_util.h"
56 #include "draw/draw_context.h"
57 #include "draw/draw_pipe.h"
58 #include "vbo/vbo.h"
59 
60 
61 /**
62  * Our special drawing pipeline stage (replaces rasterization).
63  */
64 struct rastpos_stage
65 {
66    struct draw_stage stage;   /**< Base class */
67    struct gl_context *ctx;            /**< Rendering context */
68 
69    /* vertex attrib info we can setup once and re-use */
70    struct gl_vertex_array_object *VAO;
71    struct pipe_draw_info info;
72    struct pipe_draw_start_count_bias draw;
73 };
74 
75 
76 static inline struct rastpos_stage *
rastpos_stage(struct draw_stage * stage)77 rastpos_stage( struct draw_stage *stage )
78 {
79    return (struct rastpos_stage *) stage;
80 }
81 
82 static void
rastpos_flush(struct draw_stage * stage,unsigned flags)83 rastpos_flush( struct draw_stage *stage, unsigned flags )
84 {
85    /* no-op */
86 }
87 
88 static void
rastpos_reset_stipple_counter(struct draw_stage * stage)89 rastpos_reset_stipple_counter( struct draw_stage *stage )
90 {
91    /* no-op */
92 }
93 
94 static void
rastpos_tri(struct draw_stage * stage,struct prim_header * prim)95 rastpos_tri( struct draw_stage *stage, struct prim_header *prim )
96 {
97    /* should never get here */
98    assert(0);
99 }
100 
101 static void
rastpos_line(struct draw_stage * stage,struct prim_header * prim)102 rastpos_line( struct draw_stage *stage, struct prim_header *prim )
103 {
104    /* should never get here */
105    assert(0);
106 }
107 
108 static void
rastpos_destroy(struct draw_stage * stage)109 rastpos_destroy(struct draw_stage *stage)
110 {
111    struct rastpos_stage *rstage = (struct rastpos_stage*)stage;
112    _mesa_reference_vao(rstage->ctx, &rstage->VAO, NULL);
113    FREE(stage);
114 }
115 
116 
117 /**
118  * Update a raster pos attribute from the vertex result if it's present,
119  * else copy the current attrib.
120  */
121 static void
update_attrib(struct gl_context * ctx,const uint8_t * outputMapping,const struct vertex_header * vert,GLfloat * dest,GLuint result,GLuint defaultAttrib)122 update_attrib(struct gl_context *ctx, const uint8_t *outputMapping,
123               const struct vertex_header *vert,
124               GLfloat *dest,
125               GLuint result, GLuint defaultAttrib)
126 {
127    const GLfloat *src;
128    const uint8_t k = outputMapping[result];
129    if (k != 0xff)
130       src = vert->data[k];
131    else
132       src = ctx->Current.Attrib[defaultAttrib];
133    COPY_4V(dest, src);
134 }
135 
136 
137 /**
138  * Normally, this function would render a GL_POINT.
139  */
140 static void
rastpos_point(struct draw_stage * stage,struct prim_header * prim)141 rastpos_point(struct draw_stage *stage, struct prim_header *prim)
142 {
143    struct rastpos_stage *rs = rastpos_stage(stage);
144    struct gl_context *ctx = rs->ctx;
145    const GLfloat height = (GLfloat) ctx->DrawBuffer->Height;
146    struct gl_vertex_program *stvp =
147       (struct gl_vertex_program *)ctx->VertexProgram._Current;
148    const uint8_t *outputMapping = stvp->result_to_output;
149    const GLfloat *pos;
150    GLuint i;
151 
152    ctx->PopAttribState |= GL_CURRENT_BIT;
153 
154    /* if we get here, we didn't get clipped */
155    ctx->Current.RasterPosValid = GL_TRUE;
156 
157    /* update raster pos */
158    pos = prim->v[0]->data[0];
159    ctx->Current.RasterPos[0] = pos[0];
160    if (_mesa_fb_orientation(ctx->DrawBuffer) == Y_0_TOP)
161       ctx->Current.RasterPos[1] = height - pos[1]; /* invert Y */
162    else
163       ctx->Current.RasterPos[1] = pos[1];
164    ctx->Current.RasterPos[2] = pos[2];
165    ctx->Current.RasterPos[3] = pos[3];
166 
167    /* update other raster attribs */
168    update_attrib(ctx, outputMapping, prim->v[0],
169                  ctx->Current.RasterColor,
170                  VARYING_SLOT_COL0, VERT_ATTRIB_COLOR0);
171 
172    update_attrib(ctx, outputMapping, prim->v[0],
173                  ctx->Current.RasterSecondaryColor,
174                  VARYING_SLOT_COL1, VERT_ATTRIB_COLOR1);
175 
176    for (i = 0; i < ctx->Const.MaxTextureCoordUnits; i++) {
177       update_attrib(ctx, outputMapping, prim->v[0],
178                     ctx->Current.RasterTexCoords[i],
179                     VARYING_SLOT_TEX0 + i, VERT_ATTRIB_TEX0 + i);
180    }
181 
182    if (ctx->RenderMode == GL_SELECT) {
183       _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
184    }
185 }
186 
187 
188 /**
189  * Create rasterpos "drawing" stage.
190  */
191 static struct rastpos_stage *
new_draw_rastpos_stage(struct gl_context * ctx,struct draw_context * draw)192 new_draw_rastpos_stage(struct gl_context *ctx, struct draw_context *draw)
193 {
194    struct rastpos_stage *rs = CALLOC_STRUCT(rastpos_stage);
195 
196    rs->stage.draw = draw;
197    rs->stage.next = NULL;
198    rs->stage.point = rastpos_point;
199    rs->stage.line = rastpos_line;
200    rs->stage.tri = rastpos_tri;
201    rs->stage.flush = rastpos_flush;
202    rs->stage.destroy = rastpos_destroy;
203    rs->stage.reset_stipple_counter = rastpos_reset_stipple_counter;
204    rs->stage.destroy = rastpos_destroy;
205    rs->ctx = ctx;
206 
207    rs->VAO = _mesa_new_vao(ctx, ~((GLuint)0));
208    _mesa_vertex_attrib_binding(ctx, rs->VAO, VERT_ATTRIB_POS, 0);
209    _mesa_update_array_format(ctx, rs->VAO, VERT_ATTRIB_POS, 4, GL_FLOAT,
210                              GL_RGBA, GL_FALSE, GL_FALSE, GL_FALSE, 0);
211    _mesa_enable_vertex_array_attrib(ctx, rs->VAO, 0);
212 
213    rs->info.mode = MESA_PRIM_POINTS;
214    rs->info.instance_count = 1;
215    rs->draw.count = 1;
216 
217    return rs;
218 }
219 
220 
221 void
st_RasterPos(struct gl_context * ctx,const GLfloat v[4])222 st_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_STATE_MASK);
255 
256    /* This will get set only if rastpos_point(), above, gets called */
257    ctx->PopAttribState |= GL_CURRENT_BIT;
258    ctx->Current.RasterPosValid = GL_FALSE;
259 
260    /* All vertex attribs but position were previously initialized above.
261     * Just plug in position pointer now.
262     */
263    rs->VAO->VertexAttrib[VERT_ATTRIB_POS].Ptr = (GLubyte *) v;
264    ctx->NewDriverState |= ST_NEW_VERTEX_ARRAYS;
265 
266    /* The slow path merges vertex buffers, which changes vertex elements. */
267    if (!ctx->Const.UseVAOFastPath) {
268       ctx->Array.NewVertexElements = true;
269    }
270 
271    /* Save the Draw VAO before we override it. */
272    struct gl_vertex_array_object *old_vao;
273    GLbitfield old_vp_input_filter;
274 
275    _mesa_save_and_set_draw_vao(ctx, rs->VAO, VERT_BIT_POS,
276                                &old_vao, &old_vp_input_filter);
277    _mesa_set_varying_vp_inputs(ctx, VERT_BIT_POS &
278                                ctx->Array._DrawVAO->_EnabledWithMapMode);
279 
280    st_prepare_draw(ctx, ST_PIPELINE_RENDER_STATE_MASK);
281    st_feedback_draw_vbo(ctx, &rs->info, 0, NULL, &rs->draw, 1);
282 
283    _mesa_restore_draw_vao(ctx, old_vao, old_vp_input_filter);
284 
285    /* restore draw's rasterization stage depending on rendermode */
286    if (ctx->RenderMode == GL_FEEDBACK) {
287       draw_set_rasterize_stage(draw, st->feedback_stage);
288    }
289    else if (ctx->RenderMode == GL_SELECT) {
290       draw_set_rasterize_stage(draw, st->selection_stage);
291    }
292 }
293