Fix an off-by-one mistake; Add line loops to the tessellated rendering

Stellarium · Apr 16, 2023 · 35951af · 35951af
1 parent 7054a74
commit 35951af
Show file tree

Hide file tree

Showing 2 changed files with 26 additions and 5 deletions.
diff --git a/src/core/StelPainter.cpp b/src/core/StelPainter.cpp
@@ -2400,13 +2400,21 @@ void StelPainter::enableClientStates(bool vertex, bool texture, bool color, bool
 	normalArray.enabled = normal;
 }
 
-void StelPainter::drawFixedColorWideLineStripAsQuads(const ArrayDesc& vertexArray, int count, int offset, const Mat4f& projMat)
+void StelPainter::drawFixedColorWideLineStripAsQuads(const ArrayDesc& vertexArray, int count, int offset,
+													 const Mat4f& projMat, const DrawingMode mode)
 {
+	if(count < 2) return;
+
 	GLint viewport[4] = {};
 	glGetIntegerv(GL_VIEWPORT, viewport);
 	const auto viewportSize = Vec2f(viewport[2], viewport[3]);
 
-	std::vector<Vec4f> newVertices(count*6);
+	std::vector<Vec4f> newVertices;
+	if(mode == LineStrip)
+		newVertices.reserve((count-1)*6);
+	else
+		newVertices.reserve(count*6);
+	newVertices.resize((count-1)*6);
 	assert(vertexArray.type == GL_FLOAT);
 	const auto lineVertData = static_cast<const float*>(vertexArray.pointer) + vertexArray.size*offset;
 	for(int n = 0; n < count-1; ++n)
@@ -2468,6 +2476,19 @@ void StelPainter::drawFixedColorWideLineStripAsQuads(const ArrayDesc& vertexArra
 		newVertices[6*n+4] = v0b;
 		newVertices[6*n+5] = v1b;
 	}
+	if(mode == LineLoop)
+	{
+		// Connect the ends
+		const auto lastN = newVertices.size()-1;
+		assert(lastN >= 2);
+		newVertices.push_back(newVertices[lastN-2]);
+		newVertices.push_back(newVertices[lastN]);
+		newVertices.push_back(newVertices[0]);
+
+		newVertices.push_back(newVertices[0]);
+		newVertices.push_back(newVertices[lastN]);
+		newVertices.push_back(newVertices[1]);
+	}
 	vao->bind();
 	verticesVBO->bind();
 
@@ -2523,9 +2544,9 @@ void StelPainter::drawFromArray(DrawingMode mode, int count, int offset, bool do
 	if(wideLineMode && projectedVertexArray.type == GL_FLOAT)
 	{
 		const bool fixedColor = !texCoordArray.enabled && !colorArray.enabled && !normalArray.enabled;
-		if(fixedColor && mode==LineStrip && !indices)
+		if(fixedColor && (mode != Lines) && !indices)
 		{
-			drawFixedColorWideLineStripAsQuads(projectedVertexArray, count, offset, m);
+			drawFixedColorWideLineStripAsQuads(projectedVertexArray, count, offset, m, mode);
 			return;
 		}
 	}

diff --git a/src/core/StelPainter.hpp b/src/core/StelPainter.hpp
@@ -374,7 +374,7 @@ class StelPainter : protected QOpenGLFunctions
 	//! @return a descriptor of the new array
 	ArrayDesc projectArray(const ArrayDesc& array, int offset, int count, const unsigned short *indices=Q_NULLPTR);
 
-	void drawFixedColorWideLineStripAsQuads(const ArrayDesc& vertexArray, int count, int offset, const Mat4f& projMat);
+	void drawFixedColorWideLineStripAsQuads(const ArrayDesc& vertexArray, int count, int offset, const Mat4f& projMat, DrawingMode mode);
 
 	//! Project the passed triangle on the screen ensuring that it will look smooth, even for non linear distortion
 	//! by splitting it into subtriangles. The resulting vertex arrays are appended to the passed out* ones.