Merge branch '171-bug-the-linedashlength-has-a-wrong-behavior-if-the-…

…line-is-made-of-multiple-segments' into 'master' Resolve "Bug: the `lineDashLength` has a wrong behavior if the line is made of multiple segments" Closes aerys#171 See merge request aerys/smartshape-engine!170
CitrusForks · May 9, 2019 · 955e7d7 · 955e7d7
2 parents 42487fb + 853aa7d
commit 955e7d7
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Showing 4 changed files with 22 additions and 4 deletions.
diff --git a/framework/asset/effect/Line.effect b/framework/asset/effect/Line.effect
@@ -5,7 +5,8 @@
     "attributes" : {
         "aStartPosition"  : "geometry[$geometryUuid].startPosition",
 		"aStopPosition"   : "geometry[$geometryUuid].stopPosition",
-		"aWeights"        : "geometry[$geometryUuid].weights"
+		"aWeights"        : "geometry[$geometryUuid].weights",
+		"aDashOffset"     : "geometry[$geometryUuid].dashOffset"
     },
 
     "uniforms"   : {

diff --git a/framework/asset/effect/Line.vertex.glsl b/framework/asset/effect/Line.vertex.glsl
@@ -11,6 +11,7 @@
 attribute vec3 aStartPosition;
 attribute vec3 aStopPosition;
 attribute vec3 aWeights;
+attribute float aDashOffset;
 
 uniform	mat4 uModelToWorldMatrix;
 uniform	mat4 uWorldToScreenMatrix;
@@ -26,23 +27,26 @@ main()
 	float wStart = aWeights.x;
 	float wStop = aWeights.y;
 	float lineSpread = aWeights.z;
+    vec4  dashVector = vec4(aDashOffset, 0.0, 0.0, 0.0);
 
 	vec4 startPos = vec4(aStartPosition, 1.0);
 	vec4 stopPos = vec4(aStopPosition, 1.0);
 
 	#ifdef MODEL_TO_WORLD
 		startPos = uModelToWorldMatrix * startPos;
 		stopPos	= uModelToWorldMatrix * stopPos;
+        dashVector = uModelToWorldMatrix * dashVector;
 	#endif // MODEL_TO_WORLD
 
 	startPos = uWorldToScreenMatrix * startPos;
 	stopPos = uWorldToScreenMatrix * stopPos;
+    dashVector = uWorldToScreenMatrix * dashVector;
 
 	vec4 pos = wStart * startPos + wStop * stopPos;
 	float posW = pos.w;
 
     vPosW = posW;
-    vWeight = (wStop - wStart) * distance(startPos, stopPos);
+    vWeight = length(dashVector);
 
 	// account for perspective division for screen-space offsetting
 	startPos /= startPos.w;

diff --git a/framework/include/minko/geometry/LineGeometry.hpp b/framework/include/minko/geometry/LineGeometry.hpp
@@ -37,10 +37,12 @@ namespace minko
 			static const std::string				ATTRNAME_START_POS;
 			static const std::string				ATTRNAME_STOP_POS;
 			static const std::string				ATTRNAME_WEIGHTS;
+			static const std::string				ATTRNAME_DASHOFFSET;
 
 			float									_currentX;
 			float									_currentY;
 			float									_currentZ;
+            float                                   _currentLength;
 			uint									_numLines;
 
 			std::shared_ptr<render::VertexBuffer>	_vertexBuffer;

diff --git a/framework/src/minko/geometry/LineGeometry.cpp b/framework/src/minko/geometry/LineGeometry.cpp
@@ -31,12 +31,14 @@ using namespace minko::render;
 /*static*/ const std::string LineGeometry::ATTRNAME_START_POS	= "startPosition";
 /*static*/ const std::string LineGeometry::ATTRNAME_STOP_POS    = "stopPosition";
 /*static*/ const std::string LineGeometry::ATTRNAME_WEIGHTS		= "weights";
+/*static*/ const std::string LineGeometry::ATTRNAME_DASHOFFSET	= "dashOffset";
 
 LineGeometry::LineGeometry():
 	Geometry("line"),
 	_currentX(0.f),
 	_currentY(0.f),
 	_currentZ(0.f),
+    _currentLength(0.f),
 	_numLines(0),
 	_vertexBuffer(nullptr),
 	_indexBuffer(nullptr)
@@ -55,6 +57,7 @@ LineGeometry::initialize(AbstractContext::Ptr context, int numSegments)
 	_vertexBuffer->addAttribute(ATTRNAME_START_POS,	3, 0);
 	_vertexBuffer->addAttribute(ATTRNAME_STOP_POS, 3, 3);
 	_vertexBuffer->addAttribute(ATTRNAME_WEIGHTS, 3, 6);
+    _vertexBuffer->addAttribute(ATTRNAME_DASHOFFSET, 1, 9);
 
     if (numSegments > 0)
     {
@@ -101,6 +104,7 @@ LineGeometry::lineTo(float x, float y, float z, unsigned int numSegments)
 	const float stepX = (x - _currentX) * invNumSegments;
 	const float stepY = (y - _currentY) * invNumSegments;
 	const float stepZ = (z - _currentZ) * invNumSegments;
+    const float stepLength = math::length(math::vec3(stepX, stepY, stepZ));
 	unsigned int vid = oldVertexDataSize;
 	unsigned int iid = oldIndexDataSize;
 
@@ -116,12 +120,15 @@ LineGeometry::lineTo(float x, float y, float z, unsigned int numSegments)
 		const float nextX = _currentX + stepX;
 		const float nextY = _currentY + stepY;
 		const float nextZ = _currentZ + stepZ;
+        const float nextLength = _currentLength + stepLength;
 
 		for (unsigned int k = 0; k < 4; ++k)
 		{
-			const float wStart = k < 2 ? 1.f : 0.f;
-			const float	wStop = k < 2 ? 0.f : 1.f;
+            const bool  isStart = k < 2;
+			const float wStart = isStart ? 1.f : 0.f;
+			const float	wStop = isStart ? 0.f : 1.f;
 			const float lineSpread = 0 < k && k < 3 ? 1.f : -1.f;
+            const float dashOffset = (isStart ? _currentLength : nextLength) * 2.f;
 
 			// start position
 			vertexData[vid++] = _currentX;
@@ -137,6 +144,9 @@ LineGeometry::lineTo(float x, float y, float z, unsigned int numSegments)
 			vertexData[vid++] = wStart;
 			vertexData[vid++] = wStop;
 			vertexData[vid++] = lineSpread;
+
+            // dash offset attribute
+            vertexData[vid++] = dashOffset;
 		}
 
 		const unsigned int iOffset = (_numLines << 2);
@@ -151,6 +161,7 @@ LineGeometry::lineTo(float x, float y, float z, unsigned int numSegments)
 		_currentX = nextX;
 		_currentY = nextY;
 		_currentZ = nextZ;
+        _currentLength = nextLength;
 		++_numLines;
 	}