66 lines
1.8 KiB
C++
66 lines
1.8 KiB
C++
#ifndef LLMR_GEOMETRY_LINE_BUFFER
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#define LLMR_GEOMETRY_LINE_BUFFER
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#include <vector>
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#include <cstdint>
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#include <cmath>
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namespace llmr {
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class LineBuffer {
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public:
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~LineBuffer();
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/*
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* Scale the extrusion vector so that the normal length is this value.
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* Contains the "texture" normals (-1..1). This is distinct from the extrude
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* normals for line joins, because the x-value remains 0 for the texture
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* normal array, while the extrude normal actually moves the vertex to create
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* the acute/bevelled line join.
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*/
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const int8_t extrudeScale = 63;
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/*
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* Add a vertex to this buffer
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*
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* @param {number} x vertex position
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* @param {number} y vertex position
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* @param {number} ex extrude normal
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* @param {number} ey extrude normal
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* @param {number} tx texture normal
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* @param {number} ty texture normal
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*/
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void add(int16_t x, int16_t y, float ex, float ey, int8_t tx, int8_t ty, int32_t linesofar = 0);
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/*
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* Add a degenerate triangle to the buffer
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*
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* > So we need a way to get from the end of one triangle strip
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* to the beginning of the next strip without actually filling triangles
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* on the way. We can do this with "degenerate" triangles: We simply
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* repeat the last coordinate of the first triangle strip and the first
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* coordinate of the next triangle strip.
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*/
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void addDegenerate();
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/*
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* Returns the number of elements in this buffer. This is not the number of
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* bytes, but rather the number of coordinates with associated information.
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*/
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uint32_t length() const;
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/*
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* Transfers this buffer to the GPU and binds the buffer to the GL context.
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*/
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void bind();
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private:
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bool dirty = true;
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std::vector<int16_t> array;
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uint32_t buffer = 0;
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};
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}
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#endif
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