/* * Copyright 2008 Corbin Simpson * Copyright 2009 Marek Olšák * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * on the rights to use, copy, modify, merge, publish, 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 * THE AUTHOR(S) AND/OR THEIR 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. */ #include "r300_hyperz.h" #include "r300_context.h" #include "r300_reg.h" #include "r300_fs.h" /*****************************************************************************/ /* The ZTOP state */ /*****************************************************************************/ static boolean r300_dsa_writes_stencil( struct pipe_stencil_state *s) { return s->enabled && s->writemask && (s->fail_op != PIPE_STENCIL_OP_KEEP || s->zfail_op != PIPE_STENCIL_OP_KEEP || s->zpass_op != PIPE_STENCIL_OP_KEEP); } static boolean r300_dsa_writes_depth_stencil( struct pipe_depth_stencil_alpha_state *dsa) { /* We are interested only in the cases when a depth or stencil value * can be changed. */ if (dsa->depth.enabled && dsa->depth.writemask && dsa->depth.func != PIPE_FUNC_NEVER) return TRUE; if (r300_dsa_writes_stencil(&dsa->stencil[0]) || r300_dsa_writes_stencil(&dsa->stencil[1])) return TRUE; return FALSE; } static boolean r300_dsa_alpha_test_enabled( struct pipe_depth_stencil_alpha_state *dsa) { /* We are interested only in the cases when alpha testing can kill * a fragment. */ return dsa->alpha.enabled && dsa->alpha.func != PIPE_FUNC_ALWAYS; } static void r300_update_ztop(struct r300_context* r300) { struct r300_ztop_state* ztop_state = (struct r300_ztop_state*)r300->ztop_state.state; /* This is important enough that I felt it warranted a comment. * * According to the docs, these are the conditions where ZTOP must be * disabled: * 1) Alpha testing enabled * 2) Texture kill instructions in fragment shader * 3) Chroma key culling enabled * 4) W-buffering enabled * * The docs claim that for the first three cases, if no ZS writes happen, * then ZTOP can be used. * * (3) will never apply since we do not support chroma-keyed operations. * (4) will need to be re-examined (and this comment updated) if/when * Hyper-Z becomes supported. * * Additionally, the following conditions require disabled ZTOP: * 5) Depth writes in fragment shader * 6) Outstanding occlusion queries * * This register causes stalls all the way from SC to CB when changed, * but it is buffered on-chip so it does not hurt to write it if it has * not changed. * * ~C. */ /* ZS writes */ if (r300_dsa_writes_depth_stencil(r300->dsa_state.state) && (r300_dsa_alpha_test_enabled(r300->dsa_state.state) || /* (1) */ r300_fs(r300)->shader->info.uses_kill)) { /* (2) */ ztop_state->z_buffer_top = R300_ZTOP_DISABLE; } else if (r300_fragment_shader_writes_depth(r300_fs(r300))) { /* (5) */ ztop_state->z_buffer_top = R300_ZTOP_DISABLE; } else if (r300->query_current) { /* (6) */ ztop_state->z_buffer_top = R300_ZTOP_DISABLE; } else { ztop_state->z_buffer_top = R300_ZTOP_ENABLE; } r300->ztop_state.dirty = TRUE; } void r300_update_hyperz_state(struct r300_context* r300) { r300_update_ztop(r300); }