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DrawList: added improved polyline rendering. (2183, 7972)
- added 2 variants of polyline rendering - one handles integersized thickness using one strip of triangles along the line - second handles any thickness using 2 strips of triangles long the line
This commit is contained in:
Mikko Mononen
724
imgui_draw.cpp
724
imgui_draw.cpp
@@ -844,9 +844,729 @@ void ImDrawList::PrimQuadUV(const ImVec2& a, const ImVec2& b, const ImVec2& c, c
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_IdxWritePtr += 3; \
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} (void)0
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// TODO: Thickness anti-aliased lines cap are missing their AA fringe.
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// We avoid using the ImVec2 math operators here to reduce cost to a minimum for debug/non-inlined builds.
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#define IM_POLYLINE_MITER_ANGLE_LIMIT (-0.9999619f) // cos(179.5)
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#define IM_POLYLINE_MITER_LIMIT (4.0f)
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static void CalcSegmentNormals(const ImVec2* points, const int points_count, ImVec2* normals, float* sqr_lengths, bool closed)
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{
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// Calculate normals for each line segment
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for (int i = 0; i < points_count - 1; i++)
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{
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float dx = points[i+1].x - points[i].x;
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float dy = points[i+1].y - points[i].y;
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const float d2 = dx*dx + dy*dy;
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const float inv_len = (d2 > 0.0f) ? 1.f / sqrtf(d2) : 0.f; //ImRsqrt(d2) : 0.f;
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normals[i].x = -dy * inv_len;
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normals[i].y = dx * inv_len;
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sqr_lengths[i] = d2;
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}
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if (closed)
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{
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const float dx = points[0].x - points[points_count - 1].x;
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const float dy = points[0].y - points[points_count - 1].y;
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const float d2 = dx*dx + dy*dy;
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const float inv_len = (d2 > 0.0f) ? 1.f / sqrtf(d2) : 0.f; //ImRsqrt(d2) : 0.f;
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normals[points_count - 1].x = -dy * inv_len;
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normals[points_count - 1].y = dx * inv_len;
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sqr_lengths[points_count - 1] = d2;
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}
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else
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{
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normals[points_count - 1] = normals[points_count - 2];
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sqr_lengths[points_count - 1] = 0.f;
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}
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}
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void ImDrawList::_AddPolylineThin(const ImVec2* points, const int points_count, ImU32 col, float thickness, ImDrawFlags flags, ImVec4 tex_uvs)
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{
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const bool closed = (flags & ImDrawFlags_Closed) != 0;
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_Data->TempBuffer.reserve_discard(points_count * 2);
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ImVec2* normals = _Data->TempBuffer.Data;
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float* sqr_lengths = (float*)(normals + points_count);
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CalcSegmentNormals(points, points_count, normals, sqr_lengths, closed);
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const ImU32 col_trans = col & ~IM_COL32_A_MASK;
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thickness += _FringeScale;
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const float half_thickness = thickness * 0.5f;
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const float miter_distance_limit = half_thickness * IM_POLYLINE_MITER_LIMIT;
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const float miter_distance_limit_sqr = miter_distance_limit * miter_distance_limit;
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const float half_aa = _FringeScale * 0.5f;
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// TODO: Each point will generate 2-7 vertices. The worst case happens really rarely. This can be issue with large polylines and 16it indices.
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// One option could be to calculate the miter values and overl & bevel flags before, then alloc, and finally commit.
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int idx_count = 0;
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int vtx_count = 0;
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if (closed)
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{
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vtx_count = /*body*/points_count * 7 + /*closing*/3;
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idx_count = (/*body*/points_count * 5 + /*closing*/4) * 3;
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}
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else
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{
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// Body + caps
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vtx_count = /*body*/(points_count - 2) * 7 + /*caps*/(6 * 2);
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idx_count = (/*body*/(points_count - 2) * 5 + /*last seg*/4 + /*caps*/(4 * 2)) * 3;
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}
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PrimReserve(idx_count, vtx_count);
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ImDrawVert* start_vtx_ptr = _VtxWritePtr;
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ImDrawIdx* start_idx_ptr = _IdxWritePtr;
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int base_idx = (int)_VtxCurrentIdx;
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ImVec2 p1;
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ImVec2 n1;
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float len_sqr1;
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const float half_texel = (0.5f / _FringeScale) * _Data->FontAtlas->TexUvScale.x;
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const ImVec2 uv0(tex_uvs.x + half_texel, tex_uvs.y);
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const ImVec2 uv1(tex_uvs.z - half_texel, tex_uvs.y);
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const ImVec2 uv2((uv0.x+uv1.x)*0.5f, tex_uvs.y);
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int point_idx = 0;
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int point_end = points_count;
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if (!closed)
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{
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// Start cap
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point_idx++;
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point_end--;
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p1 = points[0];
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n1 = normals[0];
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len_sqr1 = sqr_lengths[0];
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const ImVec2 dir(n1.y, -n1.x);
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const ImVec2 pa = p1 - dir * half_aa;
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const ImVec2 pb = p1 + dir * half_aa;
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base_idx = (int)_VtxCurrentIdx;
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IM_APPEND_VTX(pa.x - n1.x * half_thickness , pa.y - n1.y * half_thickness , uv0, col_trans);
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IM_APPEND_VTX(pa.x + n1.x * half_thickness , pa.y + n1.y * half_thickness , uv1, col_trans);
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int next_base_idx = (int)_VtxCurrentIdx;
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IM_APPEND_VTX(pb.x - n1.x * half_thickness , pb.y - n1.y * half_thickness , uv0, col);
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IM_APPEND_VTX(pb.x + n1.x * half_thickness , pb.y + n1.y * half_thickness , uv1, col);
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// AA cap
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IM_APPEND_TRI(base_idx + 0, base_idx + 2, base_idx + 3);
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IM_APPEND_TRI(base_idx + 0, base_idx + 3, base_idx + 1);
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base_idx = next_base_idx;
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}
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else
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{
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// Wrap around segment
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p1 = points[points_count-1];
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n1 = normals[points_count-1];
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len_sqr1 = sqr_lengths[points_count-1];
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// This will be filled later, allocate space.
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base_idx = (int)_VtxCurrentIdx;
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IM_APPEND_VTX(0, 0, uv0, col);
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IM_APPEND_VTX(0, 0, uv1, col);
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}
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while (point_idx < point_end)
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{
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ImVec2 n0 = n1;
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float len_sqr0 = len_sqr1;
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p1 = points[point_idx];
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n1 = normals[point_idx];
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len_sqr1 = sqr_lengths[point_idx];
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// theta is the angle between two segments
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const float cos_theta = n0.x * n1.x + n0.y * n1.y;
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// miter offset formula is derived here: https://www.angusj.com/clipper2/Docs/Trigonometry.htm
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const float miter_scale_factor = (cos_theta > IM_POLYLINE_MITER_ANGLE_LIMIT) ? half_thickness / (1.0f + cos_theta) : FLT_MAX; // avoid division by zero
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const float miter_offset_x = (n0.x + n1.x) * miter_scale_factor;
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const float miter_offset_y = (n0.y + n1.y) * miter_scale_factor;
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const float miter_distance_sqr = miter_offset_x * miter_offset_x + miter_offset_y * miter_offset_y;
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const bool overlap = (len_sqr0 < miter_distance_sqr) || (len_sqr1 < miter_distance_sqr) || (cos_theta <= IM_POLYLINE_MITER_ANGLE_LIMIT);
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const bool bevel = miter_distance_sqr > miter_distance_limit_sqr;
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if (bevel)
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{
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// Clipped bevel
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const float sin_theta = n0.y * n1.x - n0.x * n1.y;
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float bevel_normal_x = n0.x + n1.x;
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float bevel_normal_y = n0.y + n1.y;
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IM_NORMALIZE2F_OVER_ZERO(bevel_normal_x, bevel_normal_y);
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const float signed_miter_offset = sin_theta < 0.0f ? half_thickness : -half_thickness;
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const float side_offset = half_thickness * ((n0.x * bevel_normal_x + n0.y * bevel_normal_y) - 1.f) / (n0.y * bevel_normal_x - n0.x * bevel_normal_y);
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const float pt_x = p1.x - bevel_normal_x * signed_miter_offset;
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const float pt_y = p1.y - bevel_normal_y * signed_miter_offset;
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const float sd_x = bevel_normal_y * side_offset;
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const float sd_y = -bevel_normal_x * side_offset;
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if (overlap)
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{
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// Dislocated bevel.
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if (sin_theta < 0.f)
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{
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IM_APPEND_VTX(p1.x - n0.x * half_thickness, p1.y - n0.y * half_thickness, uv0, col); // 2
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IM_APPEND_VTX(p1.x + n0.x * half_thickness, p1.y + n0.y * half_thickness, uv1, col); // 3
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IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv0, col); // 4
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IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv0, col); // 5
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IM_APPEND_VTX(p1.x, p1.y, uv2, col); // 6
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const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
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IM_APPEND_VTX(p1.x - n1.x * half_thickness, p1.y - n1.y * half_thickness, uv0, col); // 7
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IM_APPEND_VTX(p1.x + n1.x * half_thickness, p1.y + n1.y * half_thickness, uv1, col); // 8
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// Connect prev to next
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IM_APPEND_TRI(base_idx + 0, base_idx + 2, base_idx + 3);
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IM_APPEND_TRI(base_idx + 0, base_idx + 3, base_idx + 1);
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// Bevel tris
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IM_APPEND_TRI(base_idx + 6, base_idx + 2, base_idx + 4);
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IM_APPEND_TRI(base_idx + 6, base_idx + 4, base_idx + 5);
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IM_APPEND_TRI(base_idx + 6, base_idx + 5, base_idx + 7);
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base_idx = next_base_idx;
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}
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else
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{
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IM_APPEND_VTX(p1.x - n0.x * half_thickness, p1.y - n0.y * half_thickness, uv0, col); // 2
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IM_APPEND_VTX(p1.x + n0.x * half_thickness, p1.y + n0.y * half_thickness, uv1, col); // 3
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IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv1, col); // 4
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IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv1, col); // 5
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IM_APPEND_VTX(p1.x, p1.y, uv2, col); // 6
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const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
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IM_APPEND_VTX(p1.x - n1.x * half_thickness, p1.y - n1.y * half_thickness, uv0, col); // 7
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IM_APPEND_VTX(p1.x + n1.x * half_thickness, p1.y + n1.y * half_thickness, uv1, col); // 8
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// Connect prev to next
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IM_APPEND_TRI(base_idx + 0, base_idx + 2, base_idx + 3);
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IM_APPEND_TRI(base_idx + 0, base_idx + 3, base_idx + 1);
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// Bevel
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IM_APPEND_TRI(base_idx + 6, base_idx + 7, base_idx + 5);
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IM_APPEND_TRI(base_idx + 6, base_idx + 5, base_idx + 4);
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IM_APPEND_TRI(base_idx + 6, base_idx + 4, base_idx + 3);
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base_idx = next_base_idx;
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}
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}
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else
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{
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// Bevel
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if (sin_theta < 0.f)
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{
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/* IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv0, col);
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const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
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IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv0, col);
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IM_APPEND_VTX(p1.x + miter_offset_x, p1.y + miter_offset_y, uv1, col);
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// Bevel tri
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IM_APPEND_TRI(base_idx+2, base_idx+3, base_idx+4);
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// Connect prev to next
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IM_APPEND_TRI(base_idx+0, base_idx+2, base_idx+4);
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IM_APPEND_TRI(base_idx+0, base_idx+4, base_idx+1);
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base_idx = next_base_idx;*/
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IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv0, col); // 2
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IM_APPEND_VTX(p1.x, p1.y, uv2, col); // 3
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const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
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IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv0, col); // 4
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IM_APPEND_VTX(p1.x + miter_offset_x, p1.y + miter_offset_y, uv1, col); // 5
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// Connect prev to next
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IM_APPEND_TRI(base_idx + 0, base_idx + 2, base_idx + 5);
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IM_APPEND_TRI(base_idx + 0, base_idx + 5, base_idx + 1);
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// Bevel
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IM_APPEND_TRI(base_idx + 3, base_idx + 5, base_idx + 2);
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IM_APPEND_TRI(base_idx + 3, base_idx + 2, base_idx + 4);
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IM_APPEND_TRI(base_idx + 3, base_idx + 4, base_idx + 5);
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base_idx = next_base_idx;
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}
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else
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{
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IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv1, col); // 2
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IM_APPEND_VTX(p1.x, p1.y, uv2, col); // 3
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const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
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IM_APPEND_VTX(p1.x - miter_offset_x, p1.y - miter_offset_y, uv0, col); // 4
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IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv1, col); // 5
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// Connect prev to next
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IM_APPEND_TRI(base_idx + 0, base_idx + 4, base_idx + 2);
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IM_APPEND_TRI(base_idx + 0, base_idx + 2, base_idx + 1);
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// Bevel
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IM_APPEND_TRI(base_idx + 3, base_idx + 2, base_idx + 4);
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IM_APPEND_TRI(base_idx + 3, base_idx + 4, base_idx + 5);
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IM_APPEND_TRI(base_idx + 3, base_idx + 5, base_idx + 2);
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base_idx = next_base_idx;
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/* IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv1, col);
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const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
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IM_APPEND_VTX(p1.x - miter_offset_x, p1.y - miter_offset_y, uv0, col);
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IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv1, col);
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// Bevel tri
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IM_APPEND_TRI(base_idx + 3, base_idx + 4, base_idx + 2);
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// Connect prev to next
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IM_APPEND_TRI(base_idx + 0, base_idx + 3, base_idx + 2);
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IM_APPEND_TRI(base_idx + 0, base_idx + 2, base_idx + 1);
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base_idx = next_base_idx;*/
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}
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}
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}
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else
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{
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if (overlap)
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{
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// Dislocated Miter
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const float sin_theta = n0.y * n1.x - n0.x * n1.y;
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if (sin_theta < 0.f)
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{
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IM_APPEND_VTX(p1.x - n0.x * half_thickness, p1.y - n0.y * half_thickness, uv0, col); // 2
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IM_APPEND_VTX(p1.x + n0.x * half_thickness, p1.y + n0.y * half_thickness, uv1, col); // 3
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IM_APPEND_VTX(p1.x - miter_offset_x, p1.y - miter_offset_y, uv0, col); // 4
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IM_APPEND_VTX(p1.x, p1.y, uv2, col); // 5
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const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
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IM_APPEND_VTX(p1.x - n1.x * half_thickness, p1.y - n1.y * half_thickness, uv0, col); // 6
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IM_APPEND_VTX(p1.x + n1.x * half_thickness, p1.y + n1.y * half_thickness, uv1, col); // 7
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// Connect prev to next
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IM_APPEND_TRI(base_idx+0, base_idx+2, base_idx+3);
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IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+1);
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// Miter
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IM_APPEND_TRI(base_idx+5, base_idx+2, base_idx+4);
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IM_APPEND_TRI(base_idx+5, base_idx+4, base_idx+6);
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base_idx = next_base_idx;
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}
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else
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{
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IM_APPEND_VTX(p1.x - n0.x * half_thickness, p1.y - n0.y * half_thickness, uv0, col); // 2
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IM_APPEND_VTX(p1.x + n0.x * half_thickness, p1.y + n0.y * half_thickness, uv1, col); // 3
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IM_APPEND_VTX(p1.x + miter_offset_x, p1.y + miter_offset_y, uv1, col); // 4
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IM_APPEND_VTX(p1.x, p1.y, uv2, col); // 5
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const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
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IM_APPEND_VTX(p1.x - n1.x * half_thickness, p1.y - n1.y * half_thickness, uv0, col); // 6
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IM_APPEND_VTX(p1.x + n1.x * half_thickness, p1.y + n1.y * half_thickness, uv1, col); // 7
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// Connect prev to next
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IM_APPEND_TRI(base_idx+0, base_idx+2, base_idx+3);
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IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+1);
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// Miter
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IM_APPEND_TRI(base_idx+5, base_idx+4, base_idx+3);
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IM_APPEND_TRI(base_idx+5, base_idx+7, base_idx+4);
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base_idx = next_base_idx;
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}
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}
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else
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{
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// Miter
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const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
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IM_APPEND_VTX(p1.x - miter_offset_x, p1.y - miter_offset_y, uv0, col); // 2
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IM_APPEND_VTX(p1.x + miter_offset_x, p1.y + miter_offset_y, uv1, col); // 3
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// Connect prev to next
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IM_APPEND_TRI(base_idx+0, base_idx+2, base_idx+3);
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||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+1);
|
||||
|
||||
base_idx = next_base_idx;
|
||||
}
|
||||
}
|
||||
|
||||
point_idx++;
|
||||
}
|
||||
|
||||
// End cap
|
||||
if (!closed)
|
||||
{
|
||||
p1 = points[points_count-1];
|
||||
n1 = normals[points_count-1];
|
||||
|
||||
// End cap
|
||||
const ImVec2 dir(n1.y, -n1.x);
|
||||
const ImVec2 pa = p1 - dir * half_aa;
|
||||
const ImVec2 pb = p1 + dir * half_aa;
|
||||
|
||||
int next_base_idx = (int)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(pa.x - n1.x * half_thickness, pa.y - n1.y * half_thickness, uv0, col);
|
||||
IM_APPEND_VTX(pa.x + n1.x * half_thickness, pa.y + n1.y * half_thickness, uv1, col);
|
||||
|
||||
IM_APPEND_VTX(pb.x - n1.x * half_thickness, pb.y - n1.y * half_thickness, uv0, col_trans);
|
||||
IM_APPEND_VTX(pb.x + n1.x * half_thickness, pb.y + n1.y * half_thickness, uv1, col_trans);
|
||||
|
||||
// Connect
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+2, base_idx+3);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+1);
|
||||
base_idx = next_base_idx;
|
||||
|
||||
// AA cap
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+2, base_idx+3);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+1);
|
||||
}
|
||||
else
|
||||
{
|
||||
// Connect the path.
|
||||
start_vtx_ptr[0] = VtxBuffer.Data[base_idx+0];
|
||||
start_vtx_ptr[1] = VtxBuffer.Data[base_idx+1];
|
||||
}
|
||||
|
||||
// Restore unused memory
|
||||
const int vtx_used = (int)(_VtxWritePtr - start_vtx_ptr);
|
||||
const int idx_used = (int)(_IdxWritePtr - start_idx_ptr);
|
||||
IM_ASSERT(vtx_used <= vtx_count && idx_used <= idx_count);
|
||||
PrimUnreserve(idx_count - idx_used, vtx_count - vtx_used);
|
||||
}
|
||||
|
||||
void ImDrawList::_AddPolylineThick(const ImVec2* points, const int points_count, ImU32 col, float thickness, ImDrawFlags flags)
|
||||
{
|
||||
const bool closed = (flags & ImDrawFlags_Closed) != 0;
|
||||
|
||||
_Data->TempBuffer.reserve_discard(points_count * 2);
|
||||
ImVec2* normals = _Data->TempBuffer.Data;
|
||||
float* sqr_lengths = (float*)(normals + points_count);
|
||||
CalcSegmentNormals(points, points_count, normals, sqr_lengths, closed);
|
||||
|
||||
const ImU32 col_trans = col & ~IM_COL32_A_MASK;
|
||||
|
||||
// TODO: we can expand this by having one very long texture strip for the lines,
|
||||
// or if place black 2x2 pixel next to the while pixel, and use texture clamping (that thickness would expand out of the texture).
|
||||
const float max_width = (IM_DRAWLIST_TEX_LINES_WIDTH_MAX-1) * _FringeScale * 2.f;
|
||||
thickness = ImMin(thickness, max_width);
|
||||
|
||||
thickness += _FringeScale; // Place half of AA fringe each side of the line.
|
||||
const float half_thickness = thickness * 0.5f;
|
||||
const float miter_distance_limit = half_thickness * IM_POLYLINE_MITER_LIMIT;
|
||||
const float miter_distance_limit_sqr = miter_distance_limit * miter_distance_limit;
|
||||
const float half_aa = _FringeScale * 0.5f;
|
||||
|
||||
int idx_count = 0;
|
||||
int vtx_count = 0;
|
||||
if (closed)
|
||||
{
|
||||
vtx_count = /*body*/points_count * 5 + /*closing*/3;
|
||||
idx_count = (/*body*/points_count * 5 + /*closing*/4) * 3;
|
||||
}
|
||||
else
|
||||
{
|
||||
// Body + caps
|
||||
vtx_count = /*body*/(points_count - 2) * 5 + /*caps*/(6 * 2);
|
||||
idx_count = (/*body*/(points_count - 2) * 5 + /*last seg*/4 + /*caps*/(4 * 2)) * 3;
|
||||
}
|
||||
|
||||
PrimReserve(idx_count, vtx_count);
|
||||
|
||||
ImDrawVert* start_vtx_ptr = _VtxWritePtr;
|
||||
ImDrawIdx* start_idx_ptr = _IdxWritePtr;
|
||||
|
||||
int base_idx = (int)_VtxCurrentIdx;
|
||||
|
||||
ImVec2 p1;
|
||||
ImVec2 n1;
|
||||
float len_sqr1;
|
||||
|
||||
const ImVec4 tex_uvs = _Data->TexUvLines[IM_DRAWLIST_TEX_LINES_WIDTH_MAX];
|
||||
const ImVec2 uv_out(tex_uvs.x + (0.5f / _FringeScale) * _Data->FontAtlas->TexUvScale.x, tex_uvs.y);
|
||||
const ImVec2 uv_in(tex_uvs.x + ((half_thickness + 0.5f) / _FringeScale) * _Data->FontAtlas->TexUvScale.x, tex_uvs.y);
|
||||
|
||||
int point_idx = 0;
|
||||
int point_end = points_count;
|
||||
if (!closed)
|
||||
{
|
||||
point_idx++;
|
||||
point_end--;
|
||||
p1 = points[0];
|
||||
n1 = normals[0];
|
||||
len_sqr1 = sqr_lengths[0];
|
||||
|
||||
// Start cap
|
||||
const ImVec2 dir(n1.y, -n1.x);
|
||||
const ImVec2 pa = p1 - dir * half_aa;
|
||||
const ImVec2 pb = p1 + dir * half_aa;
|
||||
|
||||
base_idx = (int)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(pa.x - n1.x * half_thickness , pa.y - n1.y * half_thickness , uv_out, col_trans);
|
||||
IM_APPEND_VTX(pa.x, pa.y, uv_in, col_trans);
|
||||
IM_APPEND_VTX(pa.x + n1.x * half_thickness , pa.y + n1.y * half_thickness , uv_out, col_trans);
|
||||
|
||||
int next_base_idx = (int)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(pb.x - n1.x * half_thickness , pb.y - n1.y * half_thickness , uv_out, col);
|
||||
IM_APPEND_VTX(pb.x, pb.y, uv_in, col);
|
||||
IM_APPEND_VTX(pb.x + n1.x * half_thickness , pb.y + n1.y * half_thickness , uv_out, col);
|
||||
|
||||
// AA cap
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+4);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+4, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+4, base_idx+5);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+5, base_idx+2);
|
||||
base_idx = next_base_idx;
|
||||
}
|
||||
else
|
||||
{
|
||||
p1 = points[points_count-1];
|
||||
n1 = normals[points_count-1];
|
||||
len_sqr1 = sqr_lengths[points_count-1];
|
||||
|
||||
// This will be filled later, allocate space.
|
||||
base_idx = (int)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(0, 0, uv_out, col);
|
||||
IM_APPEND_VTX(0, 0, uv_in, col);
|
||||
IM_APPEND_VTX(0, 0, uv_out, col);
|
||||
}
|
||||
|
||||
while (point_idx < point_end)
|
||||
{
|
||||
ImVec2 n0 = n1;
|
||||
float len_sqr0 = len_sqr1;
|
||||
p1 = points[point_idx];
|
||||
n1 = normals[point_idx];
|
||||
len_sqr1 = sqr_lengths[point_idx];
|
||||
|
||||
// theta is the angle between two segments
|
||||
const float cos_theta = n0.x * n1.x + n0.y * n1.y;
|
||||
|
||||
// miter offset formula is derived here: https://www.angusj.com/clipper2/Docs/Trigonometry.htm
|
||||
const float miter_scale_factor = (cos_theta > IM_POLYLINE_MITER_ANGLE_LIMIT) ? half_thickness / (1.0f + cos_theta) : FLT_MAX; // avoid division by zero
|
||||
const float miter_offset_x = (n0.x + n1.x) * miter_scale_factor;
|
||||
const float miter_offset_y = (n0.y + n1.y) * miter_scale_factor;
|
||||
const float miter_distance_sqr = miter_offset_x * miter_offset_x + miter_offset_y * miter_offset_y;
|
||||
|
||||
const bool overlap = (len_sqr0 < miter_distance_sqr) || (len_sqr1 < miter_distance_sqr) || (cos_theta <= IM_POLYLINE_MITER_ANGLE_LIMIT);
|
||||
const bool bevel = miter_distance_sqr > miter_distance_limit_sqr;
|
||||
|
||||
if (bevel)
|
||||
{
|
||||
// Clipped bevel
|
||||
const float sin_theta = n0.y * n1.x - n0.x * n1.y;
|
||||
float bevel_normal_x = n0.x + n1.x;
|
||||
float bevel_normal_y = n0.y + n1.y;
|
||||
IM_NORMALIZE2F_OVER_ZERO(bevel_normal_x, bevel_normal_y);
|
||||
|
||||
const float signed_miter_offset = sin_theta < 0.0f ? half_thickness : -half_thickness;
|
||||
const float side_offset = half_thickness * ((n0.x * bevel_normal_x + n0.y * bevel_normal_y) - 1.f) / (n0.y * bevel_normal_x - n0.x * bevel_normal_y);
|
||||
const float pt_x = p1.x - bevel_normal_x * signed_miter_offset;
|
||||
const float pt_y = p1.y - bevel_normal_y * signed_miter_offset;
|
||||
const float sd_x = bevel_normal_y * side_offset;
|
||||
const float sd_y = -bevel_normal_x * side_offset;
|
||||
|
||||
if (overlap)
|
||||
{
|
||||
// Dislocated bevel.
|
||||
if (sin_theta < 0.f)
|
||||
{
|
||||
IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv_out, col);
|
||||
IM_APPEND_VTX(p1.x + n0.x * half_thickness, p1.y + n0.y * half_thickness, uv_out, col);
|
||||
const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv_out, col);
|
||||
IM_APPEND_VTX(p1.x, p1.y, uv_in, col);
|
||||
IM_APPEND_VTX(p1.x + n1.x * half_thickness, p1.y + n1.y * half_thickness, uv_out, col);
|
||||
|
||||
// Bevel tri
|
||||
IM_APPEND_TRI(base_idx+3, base_idx+5, base_idx+6);
|
||||
// Connect prev to next
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+6);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+6, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+6, base_idx+4);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+4, base_idx+2);
|
||||
base_idx = next_base_idx;
|
||||
}
|
||||
else
|
||||
{
|
||||
IM_APPEND_VTX(p1.x - n0.x * half_thickness, p1.y - n0.y * half_thickness, uv_out, col);
|
||||
IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv_out, col);
|
||||
const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(p1.x - n1.x * half_thickness, p1.y - n1.y * half_thickness, uv_out, col);
|
||||
IM_APPEND_VTX(p1.x, p1.y, uv_in, col);
|
||||
IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv_out, col);
|
||||
|
||||
// Bevel tri
|
||||
IM_APPEND_TRI(base_idx+6, base_idx+7, base_idx+4);
|
||||
// Connect prev to next
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+6);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+6, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+6, base_idx+4);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+4, base_idx+2);
|
||||
base_idx = next_base_idx;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
// Bevel
|
||||
if (sin_theta < 0.f)
|
||||
{
|
||||
IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv_out, col);
|
||||
const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv_out, col);
|
||||
IM_APPEND_VTX(p1.x, p1.y, uv_in, col);
|
||||
IM_APPEND_VTX(p1.x + miter_offset_x, p1.y + miter_offset_y, uv_out, col);
|
||||
|
||||
// Bevel tri
|
||||
IM_APPEND_TRI(base_idx+3, base_idx+4, base_idx+5);
|
||||
// Connect prev to next
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+5);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+5, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+5, base_idx+6);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+6, base_idx+2);
|
||||
base_idx = next_base_idx;
|
||||
}
|
||||
else
|
||||
{
|
||||
IM_APPEND_VTX(pt_x + sd_x, pt_y + sd_y, uv_out, col);
|
||||
const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(p1.x - miter_offset_x, p1.y - miter_offset_y, uv_out, col);
|
||||
IM_APPEND_VTX(p1.x, p1.y, uv_in, col);
|
||||
IM_APPEND_VTX(pt_x - sd_x, pt_y - sd_y, uv_out, col);
|
||||
|
||||
// Bevel tri
|
||||
IM_APPEND_TRI(base_idx+5, base_idx+6, base_idx+3);
|
||||
// Connect prev to next
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+4, base_idx+5);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+5, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+5, base_idx+3);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+3, base_idx+2);
|
||||
base_idx = next_base_idx;
|
||||
}
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
if (overlap)
|
||||
{
|
||||
// Dislocated miter
|
||||
const float sin_theta = n0.y * n1.x - n0.x * n1.y;
|
||||
if (sin_theta < 0.f)
|
||||
{
|
||||
IM_APPEND_VTX(p1.x + n0.x * half_thickness, p1.y + n0.y * half_thickness, uv_out, col);
|
||||
const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(p1.x - miter_offset_x, p1.y - miter_offset_y, uv_out, col);
|
||||
IM_APPEND_VTX(p1.x, p1.y, uv_in, col);
|
||||
IM_APPEND_VTX(p1.x + n1.x * half_thickness, p1.y + n1.y * half_thickness, uv_out, col);
|
||||
|
||||
// Connect prev to next
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+4, base_idx+5);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+5, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+5, base_idx+3);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+3, base_idx+2);
|
||||
|
||||
base_idx = next_base_idx;
|
||||
}
|
||||
else
|
||||
{
|
||||
IM_APPEND_VTX(p1.x - n0.x * half_thickness, p1.y - n0.y * half_thickness, uv_out, col);
|
||||
const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(p1.x - n1.x * half_thickness, p1.y - n1.y * half_thickness, uv_out, col);
|
||||
IM_APPEND_VTX(p1.x, p1.y, uv_in, col);
|
||||
IM_APPEND_VTX(p1.x + miter_offset_x, p1.y + miter_offset_y, uv_out, col);
|
||||
|
||||
// Connect prev to next
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+5);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+5, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+5, base_idx+6);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+6, base_idx+2);
|
||||
|
||||
base_idx = next_base_idx;
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
// Miter
|
||||
const int next_base_idx = (ImDrawIdx)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(p1.x - miter_offset_x, p1.y - miter_offset_y, uv_out, col);
|
||||
IM_APPEND_VTX(p1.x, p1.y, uv_in, col);
|
||||
IM_APPEND_VTX(p1.x + miter_offset_x, p1.y + miter_offset_y, uv_out, col);
|
||||
|
||||
// Connect prev to next
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+4);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+4, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+4, base_idx+5);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+5, base_idx+2);
|
||||
|
||||
base_idx = next_base_idx;
|
||||
}
|
||||
}
|
||||
|
||||
point_idx++;
|
||||
}
|
||||
|
||||
// End cap
|
||||
if (!closed)
|
||||
{
|
||||
p1 = points[points_count-1];
|
||||
n1 = normals[points_count-1];
|
||||
|
||||
// End cap
|
||||
const ImVec2 dir(n1.y, -n1.x);
|
||||
const ImVec2 pa = p1 - dir * half_aa;
|
||||
const ImVec2 pb = p1 + dir * half_aa;
|
||||
|
||||
int next_base_idx = (int)_VtxCurrentIdx;
|
||||
IM_APPEND_VTX(pa.x - n1.x * half_thickness, pa.y - n1.y * half_thickness, uv_out, col);
|
||||
IM_APPEND_VTX(pa.x, pa.y, uv_in, col);
|
||||
IM_APPEND_VTX(pa.x + n1.x * half_thickness, pa.y + n1.y * half_thickness, uv_out, col);
|
||||
|
||||
IM_APPEND_VTX(pb.x - n1.x * half_thickness, pb.y - n1.y * half_thickness, uv_out, col_trans);
|
||||
IM_APPEND_VTX(pb.x, pb.y, uv_in, col_trans);
|
||||
IM_APPEND_VTX(pb.x + n1.x * half_thickness, pb.y + n1.y * half_thickness, uv_out, col_trans);
|
||||
|
||||
// Connect
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+4);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+4, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+4, base_idx+5);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+5, base_idx+2);
|
||||
base_idx = next_base_idx;
|
||||
|
||||
// AA cap
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+3, base_idx+4);
|
||||
IM_APPEND_TRI(base_idx+0, base_idx+4, base_idx+1);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+4, base_idx+5);
|
||||
IM_APPEND_TRI(base_idx+1, base_idx+5, base_idx+2);
|
||||
}
|
||||
else
|
||||
{
|
||||
// Connect the path.
|
||||
start_vtx_ptr[0] = VtxBuffer.Data[base_idx+0];
|
||||
start_vtx_ptr[1] = VtxBuffer.Data[base_idx+1];
|
||||
start_vtx_ptr[2] = VtxBuffer.Data[base_idx+2];
|
||||
}
|
||||
|
||||
// Restore unused memory
|
||||
const int vtx_used = (int)(_VtxWritePtr - start_vtx_ptr);
|
||||
const int idx_used = (int)(_IdxWritePtr - start_idx_ptr);
|
||||
IM_ASSERT(vtx_used <= vtx_count && idx_used <= idx_count);
|
||||
PrimUnreserve(idx_count - idx_used, vtx_count - vtx_used);
|
||||
}
|
||||
|
||||
void ImDrawList::AddPolyline(const ImVec2* points, const int points_count, ImU32 col, float thickness, ImDrawFlags flags)
|
||||
{
|
||||
if (points_count < 2 || (col & IM_COL32_A_MASK) == 0)
|
||||
return;
|
||||
|
||||
float screen_thickness = thickness / _FringeScale;
|
||||
if (screen_thickness < 1.f/255.f)
|
||||
return;
|
||||
if (screen_thickness < 1.f)
|
||||
{
|
||||
const float alpha = thickness;
|
||||
col = ImGui::GetColorU32(col, alpha);
|
||||
screen_thickness = 1.f;
|
||||
thickness = _FringeScale;
|
||||
}
|
||||
|
||||
// TODO: square vs miter cap
|
||||
// TODO: support splitting very long lines to multiple draw calls.
|
||||
|
||||
// We can use cheaper rendering if the thickness is integer size.
|
||||
const int int_thickness = (int)screen_thickness;
|
||||
const bool can_use_thin = ImAbs(screen_thickness - (float)int_thickness) < 0.01f && (int_thickness >= 1 && int_thickness < IM_DRAWLIST_TEX_LINES_WIDTH_MAX);
|
||||
|
||||
if (can_use_thin)
|
||||
{
|
||||
const ImVec4 tex_uvs = _Data->TexUvLines[int_thickness];
|
||||
_AddPolylineThin(points, points_count, col, (float)int_thickness * _FringeScale, flags, tex_uvs);
|
||||
}
|
||||
else
|
||||
{
|
||||
_AddPolylineThick(points, points_count, col, thickness, flags);
|
||||
}
|
||||
}
|
||||
|
||||
void ImDrawList::AddPolylineLegacy(const ImVec2* points, const int points_count, ImU32 col, float thickness, ImDrawFlags flags)
|
||||
{
|
||||
if (points_count < 2 || (col & IM_COL32_A_MASK) == 0)
|
||||
return;
|
||||
|
||||
Reference in New Issue
Block a user