X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fgallium%2Fauxiliary%2Fdraw%2Fdraw_pipe_cull.c;h=a873edbe76c109fec647bfa1584f09e755faf357;hb=8aacaeca685c4e705a3237c2187f2f9bcef23339;hp=8177b0ac86ebaaceac5d65f803e32ea4592f5145;hpb=26831bdac594a11e51b6c4b09df78bb11444f5dd;p=mesa.git diff --git a/src/gallium/auxiliary/draw/draw_pipe_cull.c b/src/gallium/auxiliary/draw/draw_pipe_cull.c index 8177b0ac86e..a873edbe76c 100644 --- a/src/gallium/auxiliary/draw/draw_pipe_cull.c +++ b/src/gallium/auxiliary/draw/draw_pipe_cull.c @@ -1,6 +1,6 @@ /************************************************************************** - * - * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas. + * + * Copyright 2007 VMware, Inc. * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a @@ -10,111 +10,118 @@ * distribute, sub license, and/or sell copies of the Software, and to * permit persons to whom the Software is furnished to do so, subject to * the following conditions: - * + * * The above copyright notice and this permission notice (including the * next paragraph) shall be included in all copies or substantial portions * of the Software. - * + * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. - * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR + * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. - * + * **************************************************************************/ /** * \brief Drawing stage for polygon culling */ -/* Authors: Keith Whitwell +/* Authors: Keith Whitwell */ -#include "pipe/p_util.h" +#include "util/u_math.h" +#include "util/u_memory.h" #include "pipe/p_defines.h" -#include "draw_private.h" +#include "draw_pipe.h" struct cull_stage { struct draw_stage stage; - unsigned winding; /**< which winding(s) to cull (one of PIPE_WINDING_x) */ + unsigned cull_face; /**< which face(s) to cull (one of PIPE_FACE_x) */ + unsigned front_ccw; }; -static INLINE struct cull_stage *cull_stage( struct draw_stage *stage ) +static inline struct cull_stage *cull_stage( struct draw_stage *stage ) { return (struct cull_stage *)stage; } - - - +/* + * Triangles can be culled using regular face cull. + */ static void cull_tri( struct draw_stage *stage, struct prim_header *header ) { - /* Window coords: */ - const float *v0 = header->v[0]->data[0]; - const float *v1 = header->v[1]->data[0]; - const float *v2 = header->v[2]->data[0]; - - /* edge vectors e = v0 - v2, f = v1 - v2 */ - const float ex = v0[0] - v2[0]; - const float ey = v0[1] - v2[1]; - const float fx = v1[0] - v2[0]; - const float fy = v1[1] - v2[1]; - - /* det = cross(e,f).z */ - header->det = ex * fy - ey * fx; - - if (header->det != 0) { - /* if (det < 0 then Z points toward camera and triangle is - * counter-clockwise winding. - */ - unsigned winding = (header->det < 0) ? PIPE_WINDING_CCW : PIPE_WINDING_CW; - - if ((winding & cull_stage(stage)->winding) == 0) { - /* triangle is not culled, pass to next stage */ - stage->next->tri( stage->next, header ); + /* Do the regular face culling */ + { + const unsigned pos = draw_current_shader_position_output(stage->draw); + /* Window coords: */ + const float *v0 = header->v[0]->data[pos]; + const float *v1 = header->v[1]->data[pos]; + const float *v2 = header->v[2]->data[pos]; + + /* edge vectors: e = v0 - v2, f = v1 - v2 */ + const float ex = v0[0] - v2[0]; + const float ey = v0[1] - v2[1]; + const float fx = v1[0] - v2[0]; + const float fy = v1[1] - v2[1]; + + + /* det = cross(e,f).z */ + header->det = ex * fy - ey * fx; + + if (header->det != 0) { + /* if det < 0 then Z points toward the camera and the triangle is + * counter-clockwise winding. + */ + unsigned ccw = (header->det < 0); + unsigned face = ((ccw == cull_stage(stage)->front_ccw) ? + PIPE_FACE_FRONT : + PIPE_FACE_BACK); + + if ((face & cull_stage(stage)->cull_face) == 0) { + /* triangle is not culled, pass to next stage */ + stage->next->tri( stage->next, header ); + } + } else { + /* + * With zero area, this is back facing (because the spec says + * it's front facing if sign is positive?). + * Some apis apparently do not allow us to cull zero area tris + * here, in case of fill mode line (which is rather lame). + */ + if ((PIPE_FACE_BACK & cull_stage(stage)->cull_face) == 0) { + stage->next->tri( stage->next, header ); + } } } } -static void cull_first_tri( struct draw_stage *stage, +static void cull_first_tri( struct draw_stage *stage, struct prim_header *header ) { struct cull_stage *cull = cull_stage(stage); - cull->winding = stage->draw->rasterizer->cull_mode; + cull->cull_face = stage->draw->rasterizer->cull_face; + cull->front_ccw = stage->draw->rasterizer->front_ccw; stage->tri = cull_tri; stage->tri( stage, header ); } - -static void cull_line( struct draw_stage *stage, - struct prim_header *header ) -{ - stage->next->line( stage->next, header ); -} - - -static void cull_point( struct draw_stage *stage, - struct prim_header *header ) -{ - stage->next->point( stage->next, header ); -} - - static void cull_flush( struct draw_stage *stage, unsigned flags ) { stage->tri = cull_first_tri; stage->next->flush( stage->next, flags ); } + static void cull_reset_stipple_counter( struct draw_stage *stage ) { stage->next->reset_stipple_counter( stage->next ); @@ -134,17 +141,27 @@ static void cull_destroy( struct draw_stage *stage ) struct draw_stage *draw_cull_stage( struct draw_context *draw ) { struct cull_stage *cull = CALLOC_STRUCT(cull_stage); - - draw_alloc_temp_verts( &cull->stage, 0 ); + if (!cull) + goto fail; cull->stage.draw = draw; + cull->stage.name = "cull"; cull->stage.next = NULL; - cull->stage.point = cull_point; - cull->stage.line = cull_line; + cull->stage.point = draw_pipe_passthrough_point; + cull->stage.line = draw_pipe_passthrough_line; cull->stage.tri = cull_first_tri; cull->stage.flush = cull_flush; cull->stage.reset_stipple_counter = cull_reset_stipple_counter; cull->stage.destroy = cull_destroy; + if (!draw_alloc_temp_verts( &cull->stage, 0 )) + goto fail; + return &cull->stage; + +fail: + if (cull) + cull->stage.destroy( &cull->stage ); + + return NULL; }