diff options
Diffstat (limited to 'source/blender/draw/engines/overlay/overlay_antialiasing.cc')
| -rw-r--r-- | source/blender/draw/engines/overlay/overlay_antialiasing.cc | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/source/blender/draw/engines/overlay/overlay_antialiasing.cc b/source/blender/draw/engines/overlay/overlay_antialiasing.cc new file mode 100644 index 00000000000..2eefdce403c --- /dev/null +++ b/source/blender/draw/engines/overlay/overlay_antialiasing.cc @@ -0,0 +1,256 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later + * Copyright 2019 Blender Foundation. */ + +/** \file + * \ingroup draw_engine + * + * Overlay antialiasing: + * + * Most of the overlays are wires which causes a lot of flickering in motions + * due to aliasing problems. + * + * Our goal is to have a technique that works with single sample per pixel + * to avoid extra cost of managing MSAA or additional texture buffers and jitters. + * + * To solve this we use a simple and effective post-process AA. The technique + * goes like this: + * + * - During wireframe rendering, we output the line color, the line direction + * and the distance from the line for the pixel center. + * + * - Then, in a post process pass, for each pixels we gather all lines in a search area + * that could cover (even partially) the center pixel. + * We compute the coverage of each line and do a sorted alpha compositing of them. + * + * This technique has one major shortcoming compared to MSAA: + * - It handles (initial) partial visibility poorly (because of single sample). This makes + * overlapping / crossing wires a bit too thin at their intersection. + * Wireframe meshes overlaid over solid meshes can have half of the edge missing due to + * z-fighting (this has workaround). + * Another manifestation of this, is flickering of really dense wireframe if using small + * line thickness (also has workaround). + * + * The pros of this approach are many: + * - Works without geometry shader. + * - Can inflate line thickness. + * - Coverage is very close to perfect and can even be filtered (Blackman-Harris, gaussian). + * - Wires can "bleed" / overlap non-line objects since the filter is in screen-space. + * - Only uses one additional lightweight full-screen buffer (compared to MSAA/SMAA). + * - No convergence time (compared to TAA). + */ + +#include "DRW_render.h" + +#include "ED_screen.h" + +#include "overlay_private.hh" + +void OVERLAY_antialiasing_init(OVERLAY_Data *vedata) +{ + OVERLAY_FramebufferList *fbl = vedata->fbl; + OVERLAY_TextureList *txl = vedata->txl; + OVERLAY_PrivateData *pd = vedata->stl->pd; + DefaultTextureList *dtxl = DRW_viewport_texture_list_get(); + + /* Small texture which will have very small impact on render-time. */ + if (txl->dummy_depth_tx == nullptr) { + const float pixel[1] = {1.0f}; + txl->dummy_depth_tx = DRW_texture_create_2d( + 1, 1, GPU_DEPTH_COMPONENT24, DRWTextureFlag(0), pixel); + } + + if (!DRW_state_is_fbo()) { + pd->antialiasing.enabled = false; + return; + } + + bool need_wire_expansion = (G_draw.block.size_pixel > 1.0f); + pd->antialiasing.enabled = need_wire_expansion || + ((U.gpu_flag & USER_GPU_FLAG_OVERLAY_SMOOTH_WIRE) != 0); + + GPUTexture *color_tex = nullptr; + GPUTexture *line_tex = nullptr; + + if (pd->antialiasing.enabled) { + DRW_texture_ensure_fullscreen_2d(&txl->overlay_color_tx, GPU_SRGB8_A8, DRW_TEX_FILTER); + DRW_texture_ensure_fullscreen_2d(&txl->overlay_line_tx, GPU_RGBA8, DRWTextureFlag(0)); + + color_tex = txl->overlay_color_tx; + line_tex = txl->overlay_line_tx; + } + else { + /* Just a copy of the defaults frame-buffers. */ + color_tex = dtxl->color_overlay; + } + + GPU_framebuffer_ensure_config(&fbl->overlay_color_only_fb, + { + GPU_ATTACHMENT_NONE, + GPU_ATTACHMENT_TEXTURE(color_tex), + }); + GPU_framebuffer_ensure_config(&fbl->overlay_default_fb, + { + GPU_ATTACHMENT_TEXTURE(dtxl->depth), + GPU_ATTACHMENT_TEXTURE(color_tex), + }); + GPU_framebuffer_ensure_config(&fbl->overlay_line_fb, + { + GPU_ATTACHMENT_TEXTURE(dtxl->depth), + GPU_ATTACHMENT_TEXTURE(color_tex), + GPU_ATTACHMENT_TEXTURE(line_tex), + }); +} + +void OVERLAY_antialiasing_cache_init(OVERLAY_Data *vedata) +{ + OVERLAY_TextureList *txl = vedata->txl; + OVERLAY_PrivateData *pd = vedata->stl->pd; + OVERLAY_PassList *psl = vedata->psl; + DefaultTextureList *dtxl = DRW_viewport_texture_list_get(); + GPUShader *sh; + DRWShadingGroup *grp; + + if (pd->antialiasing.enabled) { + /* `antialiasing.enabled` is also enabled for wire expansion. Check here if + * anti aliasing is needed. */ + const bool do_smooth_lines = (U.gpu_flag & USER_GPU_FLAG_OVERLAY_SMOOTH_WIRE) != 0; + + DRW_PASS_CREATE(psl->antialiasing_ps, DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_ALPHA_PREMUL); + + sh = OVERLAY_shader_antialiasing(); + grp = DRW_shgroup_create(sh, psl->antialiasing_ps); + DRW_shgroup_uniform_block(grp, "globalsBlock", G_draw.block_ubo); + DRW_shgroup_uniform_bool_copy(grp, "doSmoothLines", do_smooth_lines); + DRW_shgroup_uniform_texture_ref(grp, "depthTex", &dtxl->depth); + DRW_shgroup_uniform_texture_ref(grp, "colorTex", &txl->overlay_color_tx); + DRW_shgroup_uniform_texture_ref(grp, "lineTex", &txl->overlay_line_tx); + DRW_shgroup_call_procedural_triangles(grp, nullptr, 1); + } + + /* A bit out of place... not related to antialiasing. */ + if (pd->xray_enabled) { + DRW_PASS_CREATE(psl->xray_fade_ps, DRW_STATE_WRITE_COLOR | DRW_STATE_BLEND_MUL); + + sh = OVERLAY_shader_xray_fade(); + grp = DRW_shgroup_create(sh, psl->xray_fade_ps); + DRW_shgroup_uniform_texture_ref(grp, "depthTex", &dtxl->depth); + DRW_shgroup_uniform_texture_ref(grp, "xrayDepthTex", &txl->temp_depth_tx); + DRW_shgroup_uniform_float_copy(grp, "opacity", 1.0f - pd->xray_opacity); + DRW_shgroup_call_procedural_triangles(grp, nullptr, 1); + } +} + +void OVERLAY_antialiasing_cache_finish(OVERLAY_Data *vedata) +{ + OVERLAY_FramebufferList *fbl = vedata->fbl; + OVERLAY_TextureList *txl = vedata->txl; + OVERLAY_PassList *psl = vedata->psl; + OVERLAY_PrivateData *pd = vedata->stl->pd; + DefaultTextureList *dtxl = DRW_viewport_texture_list_get(); + + if (pd->antialiasing.enabled) { + GPU_framebuffer_ensure_config(&fbl->overlay_in_front_fb, + {GPU_ATTACHMENT_TEXTURE(dtxl->depth_in_front), + GPU_ATTACHMENT_TEXTURE(txl->overlay_color_tx)}); + + GPU_framebuffer_ensure_config(&fbl->overlay_line_in_front_fb, + {GPU_ATTACHMENT_TEXTURE(dtxl->depth_in_front), + GPU_ATTACHMENT_TEXTURE(txl->overlay_color_tx), + GPU_ATTACHMENT_TEXTURE(txl->overlay_line_tx)}); + } + else { + GPU_framebuffer_ensure_config(&fbl->overlay_in_front_fb, + {GPU_ATTACHMENT_TEXTURE(dtxl->depth_in_front), + GPU_ATTACHMENT_TEXTURE(dtxl->color_overlay)}); + + GPU_framebuffer_ensure_config(&fbl->overlay_line_in_front_fb, + {GPU_ATTACHMENT_TEXTURE(dtxl->depth_in_front), + GPU_ATTACHMENT_TEXTURE(dtxl->color_overlay), + GPU_ATTACHMENT_TEXTURE(txl->overlay_line_tx)}); + } + + pd->antialiasing.do_depth_copy = !(psl->wireframe_ps == nullptr || + DRW_pass_is_empty(psl->wireframe_ps)) || + (pd->xray_enabled && pd->xray_opacity > 0.0f); + pd->antialiasing.do_depth_infront_copy = !(psl->wireframe_xray_ps == nullptr || + DRW_pass_is_empty(psl->wireframe_xray_ps)); + + const bool do_wireframe = pd->antialiasing.do_depth_copy || + pd->antialiasing.do_depth_infront_copy; + if (pd->xray_enabled || do_wireframe) { + DRW_texture_ensure_fullscreen_2d(&txl->temp_depth_tx, GPU_DEPTH24_STENCIL8, DRWTextureFlag(0)); + } +} + +void OVERLAY_antialiasing_start(OVERLAY_Data *vedata) +{ + OVERLAY_FramebufferList *fbl = vedata->fbl; + OVERLAY_PrivateData *pd = vedata->stl->pd; + + if (pd->antialiasing.enabled) { + const float clear_col[4] = {0.0f, 0.0f, 0.0f, 0.0f}; + GPU_framebuffer_bind(fbl->overlay_line_fb); + GPU_framebuffer_clear_color(fbl->overlay_line_fb, clear_col); + } + + /* If we are not in solid shading mode, we clear the depth. */ + if (DRW_state_is_fbo() && pd->clear_in_front) { + /* TODO(fclem): This clear should be done in a global place. */ + GPU_framebuffer_bind(fbl->overlay_in_front_fb); + GPU_framebuffer_clear_depth(fbl->overlay_in_front_fb, 1.0f); + } +} + +void OVERLAY_xray_depth_copy(OVERLAY_Data *vedata) +{ + OVERLAY_FramebufferList *fbl = vedata->fbl; + OVERLAY_TextureList *txl = vedata->txl; + OVERLAY_PrivateData *pd = vedata->stl->pd; + + if (DRW_state_is_fbo() && pd->antialiasing.do_depth_copy) { + DefaultTextureList *dtxl = DRW_viewport_texture_list_get(); + /* We copy the depth of the rendered geometry to be able to compare to the overlays depth. */ + GPU_texture_copy(txl->temp_depth_tx, dtxl->depth); + } + + if (DRW_state_is_fbo() && pd->xray_enabled) { + /* We then clear to not occlude the overlays directly. */ + GPU_framebuffer_bind(fbl->overlay_default_fb); + GPU_framebuffer_clear_depth(fbl->overlay_default_fb, 1.0f); + } +} + +void OVERLAY_xray_depth_infront_copy(OVERLAY_Data *vedata) +{ + OVERLAY_TextureList *txl = vedata->txl; + OVERLAY_PrivateData *pd = vedata->stl->pd; + + if (DRW_state_is_fbo() && pd->antialiasing.do_depth_infront_copy) { + DefaultTextureList *dtxl = DRW_viewport_texture_list_get(); + /* We copy the depth of the rendered geometry to be able to compare to the overlays depth. */ + GPU_texture_copy(txl->temp_depth_tx, dtxl->depth_in_front); + } +} + +void OVERLAY_xray_fade_draw(OVERLAY_Data *vedata) +{ + OVERLAY_PassList *psl = vedata->psl; + OVERLAY_PrivateData *pd = vedata->stl->pd; + + if (DRW_state_is_fbo() && pd->xray_enabled && pd->xray_opacity > 0.0f) { + /* Partially occlude overlays using the geometry depth pass. */ + DRW_draw_pass(psl->xray_fade_ps); + } +} + +void OVERLAY_antialiasing_end(OVERLAY_Data *vedata) +{ + OVERLAY_PassList *psl = vedata->psl; + OVERLAY_PrivateData *pd = vedata->stl->pd; + DefaultFramebufferList *dfbl = DRW_viewport_framebuffer_list_get(); + + if (pd->antialiasing.enabled) { + GPU_framebuffer_bind(dfbl->overlay_only_fb); + DRW_draw_pass(psl->antialiasing_ps); + } +} |