| 0,0 → 1,226 |
|---|
| /************************************************************************** |
| * |
| * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas. |
| * All Rights Reserved. |
| * |
| * 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 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 TUNGSTEN GRAPHICS 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 polygon offset state |
| * |
| * \author Keith Whitwell <keith@tungstengraphics.com> |
| * \author Brian Paul |
| */ |
| |
| #include "util/u_math.h" |
| #include "util/u_memory.h" |
| #include "draw_pipe.h" |
| |
| |
| |
| struct offset_stage { |
| struct draw_stage stage; |
| |
| float scale; |
| float units; |
| float clamp; |
| }; |
| |
| |
| |
| static INLINE struct offset_stage *offset_stage( struct draw_stage *stage ) |
| { |
| return (struct offset_stage *) stage; |
| } |
| |
| |
| |
| |
| |
| /** |
| * Offset tri Z. Some hardware can handle this, but not usually when |
| * doing unfilled rendering. |
| */ |
| static void do_offset_tri( struct draw_stage *stage, |
| struct prim_header *header ) |
| { |
| const unsigned pos = draw_current_shader_position_output(stage->draw); |
| struct offset_stage *offset = offset_stage(stage); |
| float inv_det = 1.0f / header->det; |
| |
| /* Window coords: |
| */ |
| float *v0 = header->v[0]->data[pos]; |
| float *v1 = header->v[1]->data[pos]; |
| float *v2 = header->v[2]->data[pos]; |
| |
| /* edge vectors e = v0 - v2, f = v1 - v2 */ |
| float ex = v0[0] - v2[0]; |
| float ey = v0[1] - v2[1]; |
| float ez = v0[2] - v2[2]; |
| float fx = v1[0] - v2[0]; |
| float fy = v1[1] - v2[1]; |
| float fz = v1[2] - v2[2]; |
| |
| /* (a,b) = cross(e,f).xy */ |
| float a = ey*fz - ez*fy; |
| float b = ez*fx - ex*fz; |
| |
| float dzdx = fabsf(a * inv_det); |
| float dzdy = fabsf(b * inv_det); |
| |
| float zoffset = offset->units + MAX2(dzdx, dzdy) * offset->scale; |
| |
| if (offset->clamp) |
| zoffset = (offset->clamp < 0.0f) ? MAX2(zoffset, offset->clamp) : |
| MIN2(zoffset, offset->clamp); |
| |
| /* |
| * Note: we're applying the offset and clamping per-vertex. |
| * Ideally, the offset is applied per-fragment prior to fragment shading. |
| */ |
| v0[2] = CLAMP(v0[2] + zoffset, 0.0f, 1.0f); |
| v1[2] = CLAMP(v1[2] + zoffset, 0.0f, 1.0f); |
| v2[2] = CLAMP(v2[2] + zoffset, 0.0f, 1.0f); |
| |
| stage->next->tri( stage->next, header ); |
| } |
| |
| |
| static void offset_tri( struct draw_stage *stage, |
| struct prim_header *header ) |
| { |
| struct prim_header tmp; |
| |
| tmp.det = header->det; |
| tmp.flags = header->flags; |
| tmp.pad = header->pad; |
| tmp.v[0] = dup_vert(stage, header->v[0], 0); |
| tmp.v[1] = dup_vert(stage, header->v[1], 1); |
| tmp.v[2] = dup_vert(stage, header->v[2], 2); |
| |
| do_offset_tri( stage, &tmp ); |
| } |
| |
| |
| static void offset_first_tri( struct draw_stage *stage, |
| struct prim_header *header ) |
| { |
| struct offset_stage *offset = offset_stage(stage); |
| const struct pipe_rasterizer_state *rast = stage->draw->rasterizer; |
| unsigned fill_mode = rast->fill_front; |
| boolean do_offset; |
| |
| if (rast->fill_back != rast->fill_front) { |
| /* Need to check for back-facing triangle */ |
| boolean ccw = header->det < 0.0f; |
| if (ccw != rast->front_ccw) |
| fill_mode = rast->fill_back; |
| } |
| |
| /* Now determine if we need to do offsetting for the point/line/fill mode */ |
| switch (fill_mode) { |
| case PIPE_POLYGON_MODE_FILL: |
| do_offset = rast->offset_tri; |
| break; |
| case PIPE_POLYGON_MODE_LINE: |
| do_offset = rast->offset_line; |
| break; |
| case PIPE_POLYGON_MODE_POINT: |
| do_offset = rast->offset_point; |
| break; |
| default: |
| assert(!"invalid fill_mode in offset_first_tri()"); |
| do_offset = rast->offset_tri; |
| } |
| |
| if (do_offset) { |
| offset->scale = rast->offset_scale; |
| offset->clamp = rast->offset_clamp; |
| offset->units = (float) (rast->offset_units * stage->draw->mrd); |
| } |
| else { |
| offset->scale = 0.0f; |
| offset->clamp = 0.0f; |
| offset->units = 0.0f; |
| } |
| |
| |
| stage->tri = offset_tri; |
| stage->tri( stage, header ); |
| } |
| |
| |
| |
| |
| static void offset_flush( struct draw_stage *stage, |
| unsigned flags ) |
| { |
| stage->tri = offset_first_tri; |
| stage->next->flush( stage->next, flags ); |
| } |
| |
| |
| static void offset_reset_stipple_counter( struct draw_stage *stage ) |
| { |
| stage->next->reset_stipple_counter( stage->next ); |
| } |
| |
| |
| static void offset_destroy( struct draw_stage *stage ) |
| { |
| draw_free_temp_verts( stage ); |
| FREE( stage ); |
| } |
| |
| |
| /** |
| * Create polygon offset drawing stage. |
| */ |
| struct draw_stage *draw_offset_stage( struct draw_context *draw ) |
| { |
| struct offset_stage *offset = CALLOC_STRUCT(offset_stage); |
| if (offset == NULL) |
| goto fail; |
| |
| offset->stage.draw = draw; |
| offset->stage.name = "offset"; |
| offset->stage.next = NULL; |
| offset->stage.point = draw_pipe_passthrough_point; |
| offset->stage.line = draw_pipe_passthrough_line; |
| offset->stage.tri = offset_first_tri; |
| offset->stage.flush = offset_flush; |
| offset->stage.reset_stipple_counter = offset_reset_stipple_counter; |
| offset->stage.destroy = offset_destroy; |
| |
| if (!draw_alloc_temp_verts( &offset->stage, 3 )) |
| goto fail; |
| |
| return &offset->stage; |
| |
| fail: |
| if (offset) |
| offset->stage.destroy( &offset->stage ); |
| |
| return NULL; |
| } |