![]() Regardless of how the point size is defined, it must be greater than 0, or else undefined behavior results. The point's position defines the center of that square. The size defines the number of window pixels that each side of the point's square takes up. If it is disabled, the point size is constant for all points in a primitive, and is set by the glPointSize function. If GL_PROGRAM_POINT_SIZE is enabled, then the point size comes from the output variable float gl_PointSize. To set the point size from a shader, enable the glEnable with argument (GL_PROGRAM_POINT_SIZE) to set the point size from the program. The size can be given in two methods: by the last active vertex processing shader stage or by the context's state. ![]() Points are rasterized as screen-aligned squares of a given window-space size. Points that have a Texture mapped onto them are often called "point sprites". This will cause OpenGL to interpret each individual vertex in the stream as a point. There is only one kind of point primitive: GL_POINTS. The primitive associated with the stream defines how that stream is broken down into an ordered sequence of base primitives: points, lines, or triangles. The primitive type is specified by the GS. The primitive type is defined by the abstract patch type, specified in the TES. Tessellation, after the execution of the Tessellation Evaluation Shader.The primitive type is the type specified by the rendering command. Vertex Rendering commands, defined via Vertex Specification and processed by a Vertex Shader.Where this stream comes from depends on when Primitive Assembly is taking place and which stages of the rendering pipeline are involved. The individual primitives are sometimes called "base primitives".Ī vertex stream is an ordered list of vertices. Therefore, processing a vertex stream by one of these primitive interpretations results in an ordered sequence of primitives. The other meaning of "Primitive", also referred to as a "base primitive", refers to the result of the interpretation of a vertex stream, as part of Primitive Assembly. Such sequences of vertices can be arbitrarily long. The first meaning of "Primitive" refers to the interpretation scheme used by OpenGL to determine what a stream of vertices represents when being rendered e.g. The term Primitive in OpenGL is used to refer to two similar but separate concepts.
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