v3, file/build organization

1 files changed, 415 insertions, 0 deletions

diff --git a/src/bezier.cpp b/src/bezier.cpp
new file mode 100644
index 0000000..6fca5cc
--- /dev/null
+++ b/src/bezier.cpp
@@ -0,0 +1,415 @@
+
+static real32
+Bezier_SolveYForX(v2 Point_P0, v2 Point_P1, v2 Point_P2, v2 Point_P3, real32 TargetX) {
+
+    real32 Y = 0;
+
+    v2 m1 = (Point_P2 - Point_P0) / (2 * Tau);
+    v2 m2 = (Point_P3 - Point_P1) / (2 * Tau);
+
+    real32 Precision = 0.000001;
+    real32 t = (TargetX - Point_P0.x) / (Point_P3.x - Point_P0.x);
+
+    int Iterations = 0;
+    for (;;) {
+        real32 t2 = t * t;
+        real32 t3 = t2 * t;
+        real32 mt = 1-t;
+        real32 mt2 = mt * mt;
+        real32 mt3 = mt2 * mt;
+        v2 Point = (Point_P0 * mt3) + (3 * Point_P1 * mt2 * t) + (3 * Point_P2 * mt * t2) + (Point_P3 * t3);
+
+        bool32 Cond1 = (Point.x <= (TargetX - Precision));
+        bool32 Cond2 = (Point.x >= (TargetX + Precision));
+
+        if ((Cond1 || Cond2) && Iterations < 10) {
+            t = t * TargetX / Point.x;
+            Iterations++;
+        } else {
+            Y = Point.y;
+            break;
+        }
+    }
+
+    return Y;
+}
+
+static bezier_point *
+Bezier_LookupAddress(memory *Memory, property_channel *Property, uint16 Index, bool32 AssertExists)
+{
+    Assert(Index < MAX_KEYFRAMES_PER_BLOCK); // TODO(fox): Test multiple keyframe blocks!
+    block_bezier *Bezier = (block_bezier *)Memory_Block_AddressAtIndex(Memory, F_Bezier, Property->Block_Bezier_Index[0], AssertExists);
+    return &Bezier->Point[Index];
+}
+
+static void
+Bezier_Interact_Evaluate(project_state *State, bezier_point *PointAddress, v2 *Pos, real32 GraphZoomHeight, real32 Y_Increment)
+{
+    Pos[0] = PointAddress->Pos[0];
+    Pos[1] = PointAddress->Pos[1];
+    Pos[2] = PointAddress->Pos[2];
+    if (PointAddress->IsSelected) {
+        if (State->Interact_Active == interact_type_keyframe_move) {
+            if (State->Interact_Modifier != 2)
+                Pos[PointAddress->IsSelected - 1].x += (int32)State->Interact_Offset[0];
+            if (State->Interact_Modifier != 1)
+                Pos[PointAddress->IsSelected - 1].y -= (State->Interact_Offset[1] / GraphZoomHeight / Y_Increment);
+        } else if (State->Interact_Active == interact_type_keyframe_scale) {
+            Pos[1].x += State->Interact_Offset[0];
+            Pos[2].x -= State->Interact_Offset[0];
+        } else if (State->Interact_Active == interact_type_keyframe_rotate) {
+            // how do I do this??
+            Assert(0);
+        }
+    }
+}
+
+static void
+Bezier_Add(memory *Memory, memory_table_list TableName, property_channel *Property, bezier_point PointData, uint16 *ArrayLocation)
+{
+    if (!Property->Block_Bezier_Count) {
+        // TODO(fox): Test multiple keyframe blocks!
+        Assert(Property->Keyframe_Count < MAX_KEYFRAMES_PER_BLOCK);
+        Property->Block_Bezier_Index[0] = Memory_Block_AllocateNew(Memory, F_Bezier);
+        block_bezier *Bezier = (block_bezier *)Memory_Block_AddressAtIndex(Memory, F_Bezier, Property->Block_Bezier_Index[0], 0);
+        Bezier->Occupied = true;
+        History_Action_Swap(Memory, TableName, sizeof(Property->Block_Bezier_Count), &Property->Block_Bezier_Count);
+        Property->Block_Bezier_Count++;
+    }
+    // First check to see if the point to add overlaps an existing keyframe:
+    if (ArrayLocation) {
+        for (int p = 0; p < Property->Keyframe_Count; p++) {
+            int k = ArrayLocation[p];
+            bezier_point *Point = Bezier_LookupAddress(Memory, Property, k);
+            if (Point->Pos[0].x == PointData.Pos[0].x) {
+                History_Action_Swap(Memory, F_Bezier, sizeof(*Point), Point);
+                *Point = PointData;
+                return;
+            }
+        }
+    }
+    int k = 0;
+    for (;;) {
+        bezier_point *Point = Bezier_LookupAddress(Memory, Property, k, 0);
+        if (!Point->Occupied) {
+            History_Action_Swap(Memory, F_Bezier, sizeof(*Point), Point);
+            *Point = PointData;
+            History_Action_Swap(Memory, TableName, sizeof(Property->Keyframe_Count), &Property->Keyframe_Count);
+            Property->Keyframe_Count++;
+            return;
+        }
+        k++;
+    }
+}
+
+#if 0
+// A modified version of the bezier code in ImGui with extra features for bitmap and path interaction.
+
+// Function to convert a ratio back into a point for the bezier handles.
+v2 Line_RatioToPoint(v2 a, v2 b, real32 ratio)
+{
+    v2 ab_dir = b - a;
+    real32 ab_len_sqr = ab_dir.x * ab_dir.x + ab_dir.y * ab_dir.y;
+    real32 dot = ratio*ab_len_sqr;
+    return a + ab_dir * dot / V2(ab_len_sqr);
+}
+
+// The ratio here is just the dot product divided by the squared length.
+v2 Bezier_LineClosestPoint2(v2 a, v2 b, v2 p, real32 *ratio)
+{
+    v2 ap = p - a;
+    v2 ab_dir = b - a;
+    real32 dot = ap.x * ab_dir.x + ap.y * ab_dir.y;
+    if (dot < 0.0f) {
+        *ratio = 0.0f;
+        return a;
+    }
+    real32 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;
+}
+
+// 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).
+
+// finds the point closest to p and also fills out its ratio along the curve
+static void Bezier_CubicClosestPointCasteljauStep(v2 p, v2 *p_closest, real32 ratio, real32 *r_closest, v2 *p_last, real32 *p_closest_dist2,
+                                                    real32 x1, real32 y1, real32 x2, real32 y2, real32 x3, real32 y3, real32 x4, real32 y4, real32 tess_tol, int level)
+{
+    real32 dx = x4 - x1;
+    real32 dy = y4 - y1;
+    real32 d2 = ((x2 - x4) * dy - (y2 - y4) * dx);
+    real32 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))
+    {
+        v2 p_current = V2(x4, y4);
+        real32 added_ratio;
+        v2 p_line = Bezier_LineClosestPoint2(*p_last, p_current, p, &added_ratio);
+        real32 dist2 = LengthSq(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)
+    {
+        real32 x12 = (x1 + x2)*0.5f,       y12 = (y1 + y2)*0.5f;
+        real32 x23 = (x2 + x3)*0.5f,       y23 = (y2 + y3)*0.5f;
+        real32 x34 = (x3 + x4)*0.5f,       y34 = (y3 + y4)*0.5f;
+        real32 x123 = (x12 + x23)*0.5f,    y123 = (y12 + y23)*0.5f;
+        real32 x234 = (x23 + x34)*0.5f,    y234 = (y23 + y34)*0.5f;
+        real32 x1234 = (x123 + x234)*0.5f, y1234 = (y123 + y234)*0.5f;
+        Bezier_CubicClosestPointCasteljauStep(p, p_closest, ratio, r_closest, p_last, p_closest_dist2, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1);
+        Bezier_CubicClosestPointCasteljauStep(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);
+    }
+}
+
+// finds the min/max bounds of the curve
+static void Bezier_CubicMinMaxCasteljauStep(v2 *p_min, v2 *p_max, real32 x1, real32 y1, real32 x2, real32 y2, real32 x3, real32 y3, real32 x4, real32 y4, real32 tess_tol, int level)
+{
+    real32 dx = x4 - x1;
+    real32 dy = y4 - y1;
+    real32 d2 = ((x2 - x4) * dy - (y2 - y4) * dx);
+    real32 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))
+    {
+        v2 p_current = V2(x4, y4);
+        if (p_current.x < p_min->x) {
+            p_min->x = p_current.x;
+        }
+        if (p_current.y < p_min->y) {
+            p_min->y = p_current.y;
+        }
+        if (p_current.x > p_max->x) {
+            p_max->x = p_current.x;
+        }
+        if (p_current.y > p_max->y) {
+            p_max->y = p_current.y;
+        }
+    }
+    else if (level < 10)
+    {
+        real32 x12 = (x1 + x2)*0.5f,       y12 = (y1 + y2)*0.5f;
+        real32 x23 = (x2 + x3)*0.5f,       y23 = (y2 + y3)*0.5f;
+        real32 x34 = (x3 + x4)*0.5f,       y34 = (y3 + y4)*0.5f;
+        real32 x123 = (x12 + x23)*0.5f,    y123 = (y12 + y23)*0.5f;
+        real32 x234 = (x23 + x34)*0.5f,    y234 = (y23 + y34)*0.5f;
+        real32 x1234 = (x123 + x234)*0.5f, y1234 = (y123 + y234)*0.5f;
+        Bezier_CubicMinMaxCasteljauStep(p_min, p_max, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1);
+        Bezier_CubicMinMaxCasteljauStep(p_min, p_max, x1234, y1234, x234, y234, x34, y34, x4, y4, tess_tol, level + 1);
+    }
+}
+
+// return all points
+static void Bezier_CubicCalcPointsCasteljauStep(void *Data, uint32 *Increment, real32 x1, real32 y1, real32 x2, real32 y2, real32 x3, real32 y3, real32 x4, real32 y4, real32 tess_tol, int level)
+{
+    real32 dx = x4 - x1;
+    real32 dy = y4 - y1;
+    real32 d2 = ((x2 - x4) * dy - (y2 - y4) * dx);
+    real32 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))
+    {
+        *((real32 *)Data + *Increment*3) = x4;
+        *((real32 *)Data + *Increment*3 + 1) = y4;
+        *((real32 *)Data + *Increment*3 + 2) = 0;
+        *Increment += 1;
+    }
+    else if (level < 10)
+    {
+        real32 x12 = (x1 + x2)*0.5f,       y12 = (y1 + y2)*0.5f;
+        real32 x23 = (x2 + x3)*0.5f,       y23 = (y2 + y3)*0.5f;
+        real32 x34 = (x3 + x4)*0.5f,       y34 = (y3 + y4)*0.5f;
+        real32 x123 = (x12 + x23)*0.5f,    y123 = (y12 + y23)*0.5f;
+        real32 x234 = (x23 + x34)*0.5f,    y234 = (y23 + y34)*0.5f;
+        real32 x1234 = (x123 + x234)*0.5f, y1234 = (y123 + y234)*0.5f;
+        Bezier_CubicCalcPointsCasteljauStep(Data, Increment, x1, y1, x12, y12, x123, y123, x1234, y1234, tess_tol, level + 1);
+        Bezier_CubicCalcPointsCasteljauStep(Data, Increment, x1234, y1234, x234, y234, x34, y34, x4, y4, tess_tol, level + 1);
+    }
+}
+
+real32 Bezier_CubicRatioOfPoint(v2 p1, v2 p2, v2 p3, v2 p4, v2 p)
+{
+    real32 tess_tol = TESS_TOL;
+    v2 p_last = p1;
+    v2 p_closest;
+    real32 p_closest_dist2 = FLT_MAX;
+    real32 ratio = 0;
+    Bezier_CubicClosestPointCasteljauStep(p, &p_closest, 0, &ratio, &p_last, &p_closest_dist2, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, tess_tol, 0);
+    return ratio;
+}
+
+void Bezier_CubicCalcPoints(v2 p1, v2 p2, v2 p3, v2 p4, void *Data, uint32 *Increment)
+{
+    real32 tess_tol = TESS_TOL;
+    void *Pointer = Data;
+    Bezier_CubicCalcPointsCasteljauStep(Pointer, Increment, p1.x, p1.y, p2.x, p2.y, p3.x, p3.y, p4.x, p4.y, tess_tol, 0);
+}
+
+// These functions will become more generalized as shapes are added.
+
+static void
+Mask_AddPointToLine(mask *Mask, uint16 Index, v2 Pos)
+{
+    for (int i = Mask->NumberOfPoints - 1; i > Index; i--) {
+        Mask->Point[i+1] = Mask->Point[i];
+    }
+    mask_point *PointToAdd = &Mask->Point[Index+1];
+    PointToAdd->Pos = Pos;
+    Mask->NumberOfPoints++;
+}
+
+static void
+Mask_PushPoint(mask *Mask, v2 Pos)
+{
+    mask_point *PointToAdd = &Mask->Point[Mask->NumberOfPoints];
+    PointToAdd->Pos = Pos;
+    Mask->NumberOfPoints++;
+}
+
+static void
+Mask_ShiftPointers(mask *Mask, int16 Increment, int16 StopAt) {
+    if (Increment > 0) {
+        int16 i = Mask->NumberOfPoints - 1;
+        while (i >= StopAt) {
+            mask_point *CurrentPoint = &Mask->Point[i];
+            mask_point *NextPoint = &Mask->Point[i + Increment];
+            *NextPoint = *CurrentPoint;
+            i--;
+        }
+    } else  {
+        int16 i = StopAt;
+        while (i <= Mask->NumberOfPoints - 1) {
+            mask_point *CurrentPoint = &Mask->Point[i];
+            mask_point *NextPoint = &Mask->Point[i - Increment];
+            *CurrentPoint = *NextPoint;
+            i++;
+        }
+    }
+}
+
+static void
+Mask_DeletePoint(memory *Memory, mask *Mask, uint16 Index)
+{
+    History_Entry_Commit(Memory, action_entry_default, "Delete keyframe");
+    mask_point *MaskPointIndex = &Mask->Point[Index];
+    History_Action_StoreData(Memory, MaskPointIndex, sizeof(mask_point));
+
+    History_Action_Change_Decrement(Memory, &Mask->NumberOfPoints, action_type_change_u16);
+    // History_Action_Shift(Memory, action_type_shift_bezier, Mask, -1, Index);
+    void *StartingAddress = &Mask->Point[0];
+    History_Action_Shift_2(Memory, StartingAddress, sizeof(mask_point), Mask->NumberOfPoints, -1, Index);
+    // Mask_ShiftPointers(Mask, -1, Index);
+    History_Entry_End(Memory);
+}
+
+// It's more useful to input the ratio here instead of the cursor position
+// since we have to use it to calculate the four new handle lengths (two on the
+// new point and one on each edge).
+static void
+Mask_AddPointToCurve(memory *Memory, mask *Mask, uint16 Index, real32 ratio)
+{
+    mask_point *Point0 = &Mask->Point[Index];
+    mask_point *Point1 = &Mask->Point[Index+1];
+    if (Index + 1 == Mask->NumberOfPoints)
+        Point1 = &Mask->Point[0];
+
+    v2 Point0_Pos_Right = Point0->Pos + Point0->TangentRight;
+    v2 Point1_Pos_Left = Point1->Pos + Point1->TangentLeft;
+    v2 Handle0_Half   = Line_RatioToPoint(Point0->Pos,      Point0_Pos_Right, ratio);
+    v2 Handle1_Half   = Line_RatioToPoint(Point1_Pos_Left,  Point1->Pos,      ratio);
+    v2 Top_Half       = Line_RatioToPoint(Point0_Pos_Right, Point1_Pos_Left,  ratio);
+    v2 NewHandleLeft  = Line_RatioToPoint(Handle0_Half,     Top_Half,         ratio);
+    v2 NewHandleRight = Line_RatioToPoint(Top_Half,         Handle1_Half,     ratio);
+    v2 NewPos         = Line_RatioToPoint(NewHandleLeft,    NewHandleRight,   ratio);
+
+    History_Entry_Commit(Memory, action_entry_default, "Add point to curve");
+
+    v2 NewPoint0Pos = -(Point0->Pos - Handle0_Half);
+    v2 NewPoint1Pos = -(Point1->Pos - Handle1_Half);
+    History_Action_Change_V2(Memory, &Point0->TangentRight, &Point0->TangentRight, &NewPoint0Pos);
+    History_Action_Change_V2(Memory, &Point1->TangentLeft, &Point1->TangentLeft, &NewPoint1Pos);
+
+    void *StartingAddress = &Mask->Point[0];
+    History_Action_Shift_2(Memory, StartingAddress, sizeof(mask_point), Mask->NumberOfPoints, 1, Index);
+
+    mask_point *PointToAdd = &Mask->Point[Index+1];
+
+    // NOTE(fox): The above shift duplicates the keyframe at Index into where
+    // we're writing, Index+1. I'm using the Change action (which is normally
+    // for changing values that already exist) on this intermediate keyframe
+    // slot to save having to write a bunch of special actions for shifting and
+    // adding new data.
+
+    History_Action_Change_V2(Memory, &PointToAdd->Pos, &PointToAdd->Pos, &NewPos);
+    v2 NewLeftPos = -(NewPos - NewHandleLeft);
+    v2 NewRightPos = -(NewPos - NewHandleRight);
+    History_Action_Change_V2(Memory, &PointToAdd->TangentLeft, &PointToAdd->TangentLeft, &NewLeftPos);
+    History_Action_Change_V2(Memory, &PointToAdd->TangentRight, &PointToAdd->TangentRight, &NewRightPos);
+
+    History_Action_Change_Increment(Memory, &Mask->NumberOfPoints, action_type_change_u16);
+    History_Entry_End(Memory);
+}
+
+static void
+Mask_RasterizePoints(mask *Mask)
+{
+    Mask->NumberOfVerts = 0;
+    for (int i = 0; i < Mask->NumberOfPoints; i++) {
+        mask_point Point0 = Mask->Point[i];
+        mask_point Point1 = Mask->Point[i+1];
+        if (i+1 == Mask->NumberOfPoints)
+            Point1 = Mask->Point[0];
+
+        if (Point0.HandleBezier && Point1.HandleBezier) {
+            Bezier_CubicCalcPoints(Point0.Pos, Point0.Pos + Point0.TangentRight, Point1.Pos + Point1.TangentLeft, Point1.Pos,
+                                   Mask->TriangulatedPointCache, &Mask->NumberOfVerts);
+        } else if (Point0.HandleBezier) {
+            Bezier_CubicCalcPoints(Point0.Pos, Point0.Pos + Point0.TangentRight, Point1.Pos, Point1.Pos,
+                                   Mask->TriangulatedPointCache, &Mask->NumberOfVerts);
+        } else if (Point1.HandleBezier) {
+            Bezier_CubicCalcPoints(Point0.Pos, Point0.Pos, Point1.Pos + Point1.TangentLeft, Point1.Pos,
+                                   Mask->TriangulatedPointCache, &Mask->NumberOfVerts);
+        } else {
+            real32 *Data = (real32 *)Mask->TriangulatedPointCache + Mask->NumberOfVerts*3;
+            *(Data++) = Point0.Pos.x;
+            *(Data++) = Point0.Pos.y;
+            *(Data++) = 0;
+            // NOTE(fox): CubicCalcPoints sometimes misses generating the start
+            // point of the next path in the above two cases, so I'm making
+            // straight lines always add both points as a hotfix. This leads
+            // to cases of duplicate verts, but it doesn't seem like it harms
+            // the rendering in any way.
+            *(Data++) = Point1.Pos.x;
+            *(Data++) = Point1.Pos.y;
+            *(Data++) = 0;
+            Mask->NumberOfVerts += 2;
+        }
+    }
+}
+
+void Mask_TriangulateAndRasterize(memory *Memory, project_layer *Layer, mask *Mask)
+{
+    if (!Mask->TriangulatedPointCache) {
+        Mask->TriangulatedPointCache = AllocateMemory(Memory, 50*1024, P_VectorPoints);
+    }
+    Mask_RasterizePoints(Mask);
+
+    GL_RasterizeShape(Layer, Mask);
+}
+#endif