From 02fbb3691842318bafbf6650c60516dc8041303a Mon Sep 17 00:00:00 2001 From: ocornut Date: Thu, 30 Jul 2015 21:11:07 -0600 Subject: [PATCH] ImDrawList: Add missing support for anti-aliased thick-lines (#133, also ref #288) --- imgui.cpp | 152 +++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 109 insertions(+), 43 deletions(-) diff --git a/imgui.cpp b/imgui.cpp index 994983f8..1ba25c36 100644 --- a/imgui.cpp +++ b/imgui.cpp @@ -448,7 +448,6 @@ - input: rework IO to be able to pass actual events to fix temporal aliasing issues. - input: support track pad style scrolling & slider edit. - portability: big-endian test/support (#81) - - drawlist: add support for anti-aliased lines with >1.0f thickness (#133) - memory: add a way to discard allocs of unused/transient windows. with the current architecture new windows (including popup, opened combos, listbox) perform at least 3 allocs. - misc: mark printf compiler attributes on relevant functions - misc: provide a way to compile out the entire implementation while providing a dummy API (e.g. #define IMGUI_DUMMY_IMPL) @@ -9245,6 +9244,7 @@ void ImDrawList::PrimRectUV(const ImVec2& a, const ImVec2& c, const ImVec2& uv_a _IdxWritePtr += 6; } +// TODO: Thickness anti-aliased lines cap are missing their AA fringe. void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32 col, bool closed, float thickness, bool anti_aliased) { if (points_count < 2) @@ -9258,18 +9258,20 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32 if (!closed) count = points_count-1; - if (anti_aliased && thickness == 1.0f) + const bool thick_line = thickness > 1.0f; + if (anti_aliased) { // Anti-aliased stroke const float AA_SIZE = 1.0f; const ImU32 col_trans = col & 0x00ffffff; - const int idx_count = count*12; - const int vtx_count = points_count*3; + + const int idx_count = thick_line ? count*18 : count*12; + const int vtx_count = thick_line ? points_count*4 : points_count*3; PrimReserve(idx_count, vtx_count); // Temporary buffer - ImVec2* temp_points = (ImVec2*)alloca(points_count * 3 * sizeof(ImVec2)); - ImVec2* temp_normals = temp_points + points_count * 2; + ImVec2* temp_normals = (ImVec2*)alloca(points_count * (thick_line ? 5 : 3) * sizeof(ImVec2)); + ImVec2* temp_points = temp_normals + points_count; for (int i1 = 0; i1 < count; i1++) { @@ -9279,53 +9281,117 @@ void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32 temp_normals[i1].x = diff.y; temp_normals[i1].y = -diff.x; } - if (!closed) - { temp_normals[points_count-1] = temp_normals[points_count-2]; - temp_points[0] = points[0] + temp_normals[0] * AA_SIZE; - temp_points[1] = points[0] - temp_normals[0] * AA_SIZE; - temp_points[(points_count-1)*2+0] = points[points_count-1] + temp_normals[points_count-1] * AA_SIZE; - temp_points[(points_count-1)*2+1] = points[points_count-1] - temp_normals[points_count-1] * AA_SIZE; - } - // FIXME-OPT: Merge the different loops, possibly remove the temporary buffer. - unsigned int idx1 = _VtxCurrentIdx; - for (int i1 = 0; i1 < count; i1++) + if (!thick_line) { - const int i2 = (i1+1) == points_count ? 0 : i1+1; - unsigned int idx2 = (i1+1) == points_count ? _VtxCurrentIdx : idx1+3; - - // Average normals - ImVec2 dm = (temp_normals[i1] + temp_normals[i2]) * 0.5f; - float dmr2 = dm.x*dm.x + dm.y*dm.y; - if (dmr2 > 0.000001f) + if (!closed) { - float scale = 1.0f / dmr2; - if (scale > 100.0f) scale = 100.0f; - dm *= scale; + temp_points[0] = points[0] + temp_normals[0] * AA_SIZE; + temp_points[1] = points[0] - temp_normals[0] * AA_SIZE; + temp_points[(points_count-1)*2+0] = points[points_count-1] + temp_normals[points_count-1] * AA_SIZE; + temp_points[(points_count-1)*2+1] = points[points_count-1] - temp_normals[points_count-1] * AA_SIZE; } - dm *= AA_SIZE; - temp_points[i2*2+0] = points[i2] + dm; - temp_points[i2*2+1] = points[i2] - dm; - // Add indexes - _IdxWritePtr[0] = (ImDrawIdx)(idx2+0); _IdxWritePtr[1] = (ImDrawIdx)(idx1+0); _IdxWritePtr[2] = (ImDrawIdx)(idx1+2); - _IdxWritePtr[3] = (ImDrawIdx)(idx1+2); _IdxWritePtr[4] = (ImDrawIdx)(idx2+2); _IdxWritePtr[5] = (ImDrawIdx)(idx2+0); - _IdxWritePtr[6] = (ImDrawIdx)(idx2+1); _IdxWritePtr[7] = (ImDrawIdx)(idx1+1); _IdxWritePtr[8] = (ImDrawIdx)(idx1+0); - _IdxWritePtr[9] = (ImDrawIdx)(idx1+0); _IdxWritePtr[10]= (ImDrawIdx)(idx2+0); _IdxWritePtr[11]= (ImDrawIdx)(idx2+1); - _IdxWritePtr += 12; + // FIXME-OPT: Merge the different loops, possibly remove the temporary buffer. + unsigned int idx1 = _VtxCurrentIdx; + for (int i1 = 0; i1 < count; i1++) + { + const int i2 = (i1+1) == points_count ? 0 : i1+1; + unsigned int idx2 = (i1+1) == points_count ? _VtxCurrentIdx : idx1+3; - idx1 = idx2; + // Average normals + ImVec2 dm = (temp_normals[i1] + temp_normals[i2]) * 0.5f; + float dmr2 = dm.x*dm.x + dm.y*dm.y; + if (dmr2 > 0.000001f) + { + float scale = 1.0f / dmr2; + if (scale > 100.0f) scale = 100.0f; + dm *= scale; + } + dm *= AA_SIZE; + temp_points[i2*2+0] = points[i2] + dm; + temp_points[i2*2+1] = points[i2] - dm; + + // Add indexes + _IdxWritePtr[0] = (ImDrawIdx)(idx2+0); _IdxWritePtr[1] = (ImDrawIdx)(idx1+0); _IdxWritePtr[2] = (ImDrawIdx)(idx1+2); + _IdxWritePtr[3] = (ImDrawIdx)(idx1+2); _IdxWritePtr[4] = (ImDrawIdx)(idx2+2); _IdxWritePtr[5] = (ImDrawIdx)(idx2+0); + _IdxWritePtr[6] = (ImDrawIdx)(idx2+1); _IdxWritePtr[7] = (ImDrawIdx)(idx1+1); _IdxWritePtr[8] = (ImDrawIdx)(idx1+0); + _IdxWritePtr[9] = (ImDrawIdx)(idx1+0); _IdxWritePtr[10]= (ImDrawIdx)(idx2+0); _IdxWritePtr[11]= (ImDrawIdx)(idx2+1); + _IdxWritePtr += 12; + + idx1 = idx2; + } + + // Add vertexes + for (int i = 0; i < points_count; i++) + { + _VtxWritePtr[0].pos = points[i]; _VtxWritePtr[0].uv = uv; _VtxWritePtr[0].col = col; + _VtxWritePtr[1].pos = temp_points[i*2+0]; _VtxWritePtr[1].uv = uv; _VtxWritePtr[1].col = col_trans; + _VtxWritePtr[2].pos = temp_points[i*2+1]; _VtxWritePtr[2].uv = uv; _VtxWritePtr[2].col = col_trans; + _VtxWritePtr += 3; + } } - - // Add vertexes - for (int i = 0; i < points_count; i++) + else { - _VtxWritePtr[0].pos = points[i]; _VtxWritePtr[0].uv = uv; _VtxWritePtr[0].col = col; - _VtxWritePtr[1].pos = temp_points[i*2+0]; _VtxWritePtr[1].uv = uv; _VtxWritePtr[1].col = col_trans; - _VtxWritePtr[2].pos = temp_points[i*2+1]; _VtxWritePtr[2].uv = uv; _VtxWritePtr[2].col = col_trans; - _VtxWritePtr += 3; + const float half_inner_thickness = (thickness - AA_SIZE) * 0.5f; + if (!closed) + { + temp_points[0] = points[0] + temp_normals[0] * (half_inner_thickness + AA_SIZE); + temp_points[1] = points[0] + temp_normals[0] * (half_inner_thickness); + temp_points[2] = points[0] - temp_normals[0] * (half_inner_thickness); + temp_points[3] = points[0] - temp_normals[0] * (half_inner_thickness + AA_SIZE); + temp_points[(points_count-1)*4+0] = points[points_count-1] + temp_normals[points_count-1] * (half_inner_thickness + AA_SIZE); + temp_points[(points_count-1)*4+1] = points[points_count-1] + temp_normals[points_count-1] * (half_inner_thickness); + temp_points[(points_count-1)*4+2] = points[points_count-1] - temp_normals[points_count-1] * (half_inner_thickness); + temp_points[(points_count-1)*4+3] = points[points_count-1] - temp_normals[points_count-1] * (half_inner_thickness + AA_SIZE); + } + + // FIXME-OPT: Merge the different loops, possibly remove the temporary buffer. + unsigned int idx1 = _VtxCurrentIdx; + for (int i1 = 0; i1 < count; i1++) + { + const int i2 = (i1+1) == points_count ? 0 : i1+1; + unsigned int idx2 = (i1+1) == points_count ? _VtxCurrentIdx : idx1+4; + + // Average normals + ImVec2 dm = (temp_normals[i1] + temp_normals[i2]) * 0.5f; + float dmr2 = dm.x*dm.x + dm.y*dm.y; + if (dmr2 > 0.000001f) + { + float scale = 1.0f / dmr2; + if (scale > 100.0f) scale = 100.0f; + dm *= scale; + } + ImVec2 dm_out = dm * (half_inner_thickness + AA_SIZE); + ImVec2 dm_in = dm * half_inner_thickness; + temp_points[i2*4+0] = points[i2] + dm_out; + temp_points[i2*4+1] = points[i2] + dm_in; + temp_points[i2*4+2] = points[i2] - dm_in; + temp_points[i2*4+3] = points[i2] - dm_out; + + // Add indexes + _IdxWritePtr[0] = (ImDrawIdx)(idx2+1); _IdxWritePtr[1] = (ImDrawIdx)(idx1+1); _IdxWritePtr[2] = (ImDrawIdx)(idx1+2); + _IdxWritePtr[3] = (ImDrawIdx)(idx1+2); _IdxWritePtr[4] = (ImDrawIdx)(idx2+2); _IdxWritePtr[5] = (ImDrawIdx)(idx2+1); + _IdxWritePtr[6] = (ImDrawIdx)(idx2+1); _IdxWritePtr[7] = (ImDrawIdx)(idx1+1); _IdxWritePtr[8] = (ImDrawIdx)(idx1+0); + _IdxWritePtr[9] = (ImDrawIdx)(idx1+0); _IdxWritePtr[10] = (ImDrawIdx)(idx2+0); _IdxWritePtr[11] = (ImDrawIdx)(idx2+1); + _IdxWritePtr[12] = (ImDrawIdx)(idx2+2); _IdxWritePtr[13] = (ImDrawIdx)(idx1+2); _IdxWritePtr[14] = (ImDrawIdx)(idx1+3); + _IdxWritePtr[15] = (ImDrawIdx)(idx1+3); _IdxWritePtr[16] = (ImDrawIdx)(idx2+3); _IdxWritePtr[17] = (ImDrawIdx)(idx2+2); + _IdxWritePtr += 18; + + idx1 = idx2; + } + + // Add vertexes + for (int i = 0; i < points_count; i++) + { + _VtxWritePtr[0].pos = temp_points[i*4+0]; _VtxWritePtr[0].uv = uv; _VtxWritePtr[0].col = col_trans; + _VtxWritePtr[1].pos = temp_points[i*4+1]; _VtxWritePtr[1].uv = uv; _VtxWritePtr[1].col = col; + _VtxWritePtr[2].pos = temp_points[i*4+2]; _VtxWritePtr[2].uv = uv; _VtxWritePtr[2].col = col; + _VtxWritePtr[3].pos = temp_points[i*4+3]; _VtxWritePtr[3].uv = uv; _VtxWritePtr[3].col = col_trans; + _VtxWritePtr += 4; + } } _VtxCurrentIdx += (ImDrawIdx)vtx_count; }