From 635576972024319c15141645d3304db8cd1d1e19 Mon Sep 17 00:00:00 2001 From: Fox Caminiti Date: Mon, 8 Aug 2022 13:50:34 -0400 Subject: basic bezier path system added --- my_imgui_internal_widgets.cpp | 187 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 168 insertions(+), 19 deletions(-) (limited to 'my_imgui_internal_widgets.cpp') diff --git a/my_imgui_internal_widgets.cpp b/my_imgui_internal_widgets.cpp index d8934d8..c654e36 100644 --- a/my_imgui_internal_widgets.cpp +++ b/my_imgui_internal_widgets.cpp @@ -1,5 +1,7 @@ #include "my_imgui_internal_widgets.h" + + #include "imgui.h" #ifndef IMGUI_DEFINE_MATH_OPERATORS #define IMGUI_DEFINE_MATH_OPERATORS @@ -9,14 +11,14 @@ // A modded version of ScalarSlider allowing for the minimum and maximum parts // of the slider to be draggable by two other buttons. p_mid is from range -1 // to 1, and s_min and max are from 0-1. -bool ImGui::SliderLevels(const char* label, void* p_mid, void* p_left, void* p_right) +bool ImGui::SliderLevels(const char* label, const char* label2, const char* label3, void* p_mid, void* p_left, void* p_right) { ImGuiWindow* window = GetCurrentWindow(); if (window->SkipItems) return false; - const float SliderMin = -1; - const float SliderMax = 1; + const float SliderMin = 0.1; + const float SliderMax = 10; const float OtherMin = 0; const float OtherMax = 1; const void* p_min = &SliderMin; @@ -32,14 +34,9 @@ bool ImGui::SliderLevels(const char* label, void* p_mid, void* p_left, void* p_r // I'm not well-versed in exactly what ImGui's id system does, but I'm // pretty sure it's one clickable object equals one ImGui ID. - const ImGuiID id = window->GetID(label); - PushID(label); - PushID(1); - const ImGuiID id_L = window->GetID(""); - PopID(); - PopID(); - const ImGuiID id_R = window->GetID("adsafb"); - const ImGuiID id_mid = window->GetID("asdasbdsgd"); + const ImGuiID id_L = window->GetID(label); + const ImGuiID id_R = window->GetID(label2); + const ImGuiID id_mid = window->GetID(label3); const float w = CalcItemWidth(); const ImVec2 label_size = CalcTextSize(label, NULL, true); @@ -55,30 +52,37 @@ bool ImGui::SliderLevels(const char* label, void* p_mid, void* p_left, void* p_r if (!ItemAdd(total_bb, id_mid, &frame_bb, 0)) return false; + bool any_val_changed; // Slider behavior ImRect grab_bb; const bool value_changed = SliderBehavior(frame_bb, id_L, data_type, p_left, o_min, o_max, format, flags, &grab_bb); - if (value_changed) + if (value_changed) { MarkItemEdited(id_L); + any_val_changed = true; + } ImRect grab_bb2; const bool value_changed2 = SliderBehavior(frame_bb, id_R, data_type, p_right, o_min, o_max, format, flags, &grab_bb2); - if (value_changed2) + if (value_changed2) { MarkItemEdited(id_R); + any_val_changed = true; + } const ImRect mid_bb(ImVec2(grab_bb.Max.x, frame_bb.Min.y), ImVec2(grab_bb2.Min.x, frame_bb.Max.y)); // Slider behavior ImRect grab_bb3; - const bool value_changed3 = SliderBehavior(mid_bb, id_mid, data_type, p_mid, p_min, p_max, format, flags, &grab_bb3); - if (value_changed3) + const bool value_changed3 = SliderBehavior(mid_bb, id_mid, data_type, p_mid, p_min, p_max, format, flags | ImGuiSliderFlags_Logarithmic, &grab_bb3); + if (value_changed3) { MarkItemEdited(id_mid); + any_val_changed = true; + } - const bool hovered = ItemHoverable(frame_bb, id); + const bool hovered = ItemHoverable(frame_bb, id_L); const bool input_requested_by_tabbing = (g.LastItemData.StatusFlags & ImGuiItemStatusFlags_FocusedByTabbing) != 0; const bool clicked = (hovered && g.IO.MouseClicked[0]); - const bool make_active = (input_requested_by_tabbing || clicked || g.NavActivateId == id || g.NavActivateInputId == id); + const bool make_active = (input_requested_by_tabbing || clicked || g.NavActivateId == id_L || g.NavActivateInputId == id_L); if (make_active) { @@ -119,7 +123,7 @@ bool ImGui::SliderLevels(const char* label, void* p_mid, void* p_left, void* p_r // Display value using user-provided display format so user can add prefix/suffix/decorations to the value. char value_buf[64]; - const char* value_buf_end = value_buf + DataTypeFormatString(value_buf, IM_ARRAYSIZE(value_buf), data_type, p_left, format); + const char* value_buf_end = value_buf + DataTypeFormatString(value_buf, IM_ARRAYSIZE(value_buf), data_type, p_mid, format); if (g.LogEnabled) LogSetNextTextDecoration("{", "}"); RenderTextClipped(frame_bb.Min, frame_bb.Max, value_buf, value_buf_end, NULL, ImVec2(0.5f, 0.5f)); @@ -128,5 +132,150 @@ bool ImGui::SliderLevels(const char* label, void* p_mid, void* p_left, void* p_r RenderText(ImVec2(frame_bb.Max.x + style.ItemInnerSpacing.x, frame_bb.Min.y + style.FramePadding.y), label); IMGUI_TEST_ENGINE_ITEM_INFO(id, label, g.LastItemData.StatusFlags); - return value_changed; + return any_val_changed; +} + +bool ImGui::TestLine(ImVec2 p0, ImVec2 p1) +{ + ImGuiContext& g = *GImGui; + ImGuiWindow* window = GetCurrentWindow(); + if (window->SkipItems) + return false; + + bool Toggle = false; + + ImDrawList* draw_list = window->DrawList; + // ImGuiStyle& style = g.Style; + + ImVec2 point = ImLineClosestPoint(p0, p1, g.IO.MousePos); + + ImU32 col = ImGui::GetColorU32(ImGuiCol_ScrollbarGrab); + + if (abs(g.IO.MousePos.x - point.x) < 3 && abs(g.IO.MousePos.y - point.y) < 3 && + point.x != p0.x && point.y != p0.y && + point.x != p1.x && point.y != p1.y) + { + col = ImGui::GetColorU32(ImGuiCol_Button); + Toggle = true; + } + + draw_list->AddLine(p0, p1, col, 2.0f); + + return Toggle; +} + +// Slightly modified version of the bezier closest point lookup code that +// additionally outputs the ratio of the closest point along the curve for use +// in constructing the handles of new points. + + +// The ratio here is just the dot product divided by the squared length. +ImVec2 ImLineClosestPoint2(const ImVec2& a, const ImVec2& b, const ImVec2& p, float& ratio) +{ + ImVec2 ap = p - a; + ImVec2 ab_dir = b - a; + float dot = ap.x * ab_dir.x + ap.y * ab_dir.y; + if (dot < 0.0f) { + ratio = 0.0f; + return a; + } + float ab_len_sqr = ab_dir.x * ab_dir.x + ab_dir.y * ab_dir.y; + if (dot > ab_len_sqr) { + ratio = 1.0f; + return b; + } + ratio = dot / ab_len_sqr; + return a + ab_dir * dot / ab_len_sqr; +} + +// Function to convert a ratio back into a point for the bezier handles. +ImVec2 ImGui::RatioToPoint(const ImVec2& a, const ImVec2& b, float ratio) +{ + ImVec2 ab_dir = b - a; + float ab_len_sqr = ab_dir.x * ab_dir.x + ab_dir.y * ab_dir.y; + float dot = ratio*ab_len_sqr; + return a + ab_dir * dot / ab_len_sqr; +} + + +// Following the algorithm, we take the ratio from the _leftmost_ point in each +// subdivision of the cubic spline until we're within tess_tol, and then we +// interpolate it with the subdivision's rightmost point in the ClosestPoint call. +// The pow(0.5, level) represents the ratio of the next subdivision's leftmost +// point (AKA the rightmost point of the current subdivision). + +static void ImBezierCubicClosestPointCasteljauStep2(const ImVec2& p, ImVec2& p_closest, float ratio, float& r_closest, ImVec2& p_last, float& p_closest_dist2, float x1, float y1, float x2, float y2, float x3, float y3, float x4, float y4, float tess_tol, int level) +{ + float dx = x4 - x1; + float dy = y4 - y1; + float d2 = ((x2 - x4) * dy - (y2 - y4) * dx); + float d3 = ((x3 - x4) * dy - (y3 - y4) * dx); + d2 = (d2 >= 0) ? d2 : -d2; + d3 = (d3 >= 0) ? d3 : -d3; + if ((d2 + d3) * (d2 + d3) < tess_tol * (dx * dx + dy * dy)) + { + ImVec2 p_current(x4, y4); + float added_ratio; + ImVec2 p_line = ImLineClosestPoint2(p_last, p_current, p, added_ratio); + float dist2 = ImLengthSqr(p - p_line); + if (dist2 < p_closest_dist2) + { + p_closest = p_line; + p_closest_dist2 = dist2; + r_closest = ratio + pow(0.5, level)*added_ratio; + } + p_last = p_current; + } + else if (level < 10) + { + float x12 = (x1 + x2)*0.5f, y12 = (y1 + y2)*0.5f; + float x23 = (x2 + x3)*0.5f, y23 = (y2 + y3)*0.5f; + float x34 = (x3 + x4)*0.5f, y34 = (y3 + y4)*0.5f; + float x123 = (x12 + x23)*0.5f, y123 = (y12 + y23)*0.5f; + float x234 = (x23 + x34)*0.5f, y234 = (y23 + y34)*0.5f; + float x1234 = (x123 + x234)*0.5f, y1234 = (y123 + y234)*0.5f; + ImBezierCubicClosestPointCasteljauStep2(p, p_closest, ratio, r_closest, p_last, p_closest_dist2, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1); + ImBezierCubicClosestPointCasteljauStep2(p, p_closest, ratio + pow(0.5, level+1), r_closest, p_last, p_closest_dist2, x1234, y1234, x234, y234, x34, y34, x4, y4, tess_tol, level + 1); + } +} + +ImVec2 ImBezierCubicClosestPointCasteljau2(const ImVec2& p1, const ImVec2& p2, const ImVec2& p3, const ImVec2& p4, const ImVec2& p, float& ratio, float tess_tol) +{ + IM_ASSERT(tess_tol > 0.0f); + ImVec2 p_last = p1; + ImVec2 p_closest; + float p_closest_dist2 = FLT_MAX; + float r_closest; + ImBezierCubicClosestPointCasteljauStep2(p, p_closest, 0, r_closest, p_last, p_closest_dist2, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, tess_tol, 0); + ratio = r_closest; + return p_closest; +} + +// Returns true when cursor is close to the curve but not too close to the beginning/end points. +bool ImGui::BezierInteractive(ImVec2 p0, ImVec2 p1, ImVec2 p2, ImVec2 p3, float& ratio) +{ + bool hovered = false; + + ImGuiContext& g = *GImGui; + ImGuiWindow* window = GetCurrentWindow(); + if (window->SkipItems) + return false; + + ImDrawList* draw_list = window->DrawList; + ImU32 col = ImGui::GetColorU32(ImGuiCol_ScrollbarGrab); + + ImVec2 point = ImBezierCubicClosestPointCasteljau2(p0, p1, p2, p3, g.IO.MousePos, ratio, GetStyle().CurveTessellationTol); + + + if (abs(g.IO.MousePos.x - point.x) < 3 && abs(g.IO.MousePos.y - point.y) < 3 && + abs(p0.x - point.x) > 3 && abs(p0.y - point.y) > 3 && + abs(p1.x - point.x) > 3 && abs(p1.y - point.y) > 3) + { + col = GetColorU32(ImGuiCol_Button); + hovered = true; + } + + draw_list->AddBezierCubic(p0, p1, p2, p3, col, 2.0f, 0); + + return hovered; } -- cgit v1.2.3