A device comprising: at least one processor; and one or more computer-readable storage media including instructions stored thereon that, responsive to execution by the at least one processor, cause the device to perform operations including: performing an interior tessellation on a geometric primitive to generate a tessellated primitive; processing the tessellated primitive based on displacement vectors calculated for the tessellated primitive to generate a processed primitive with displaced vertices; generating quadrilaterals for edges of the tessellated primitive based on edge unit normal vectors for the edges and based on displacement vectors calculated using the edge unit normal vectors, the quadrilaterals including a coverage gradient; generating triangles that are generated to fill gaps between adjacent quadrilaterals, for convex vertices of the tessellated primitive, the triangles including a coverage gradient and being based on edge unit normal vectors of the convex vertices; and processing the processed primitive, the quadrilaterals, and the triangles for display to provide anti-aliasing of the primitive, wherein said processing the processed primitive, the quadrilaterals, and the triangles for display comprises: processing vertices of the processed primitive, the quadrilaterals, and the triangles to generate a position and coverage values for the vertices; and calculating modulated colors for the vertices based on respective coverage values and a brush specified for the vertices, whereby said brush specifies a particular colour value for a particular pixel covered by the primitive. at least one processor; and one or more computer-readable storage media including instructions stored thereon that, responsive to execution by the at least one processor, cause the device to perform operations including: performing an interior tessellation on a geometric primitive to generate a tessellated primitive; processing the tessellated primitive based on displacement vectors calculated for the tessellated primitive to generate a processed primitive with displaced vertices; generating quadrilaterals for edges of the tessellated primitive based on edge unit normal vectors for the edges and based on displacement vectors calculated using the edge unit normal vectors, the quadrilaterals including a coverage gradient; generating triangles that are generated to fill gaps between adjacent quadrilaterals, for convex vertices of the tessellated primitive, the triangles including a coverage performing an interior tessellation on a geometric primitive to generate a tessellated primitive; processing the tessellated primitive based on displacement vectors calculated for the tessellated primitive to generate a processed primitive with displaced vertices; generating quadrilaterals for edges of the tessellated primitive based on edge unit normal vectors for the edges and based on displacement vectors calculated using the edge unit normal vectors, the quadrilaterals including a coverage gradient; generating triangles that are generated to fill gaps between adjacent quadrilaterals, for convex vertices of the tessellated primitive, the triangles including a coverage gradient and being based on edge unit normal vectors of the convex vertices; and processing the processed primitive, the quadrilaterals, and the triangles for display to provide anti-aliasing of the primitive, wherein said processing the processed primitive, the quadrilaterals, and the triangles for display comprises: processing vertices of the processed primitive, the quadrilaterals, and the triangles to generate a position and coverage values for the vertices; and calculating modulated colors for the vertices based on respective coverage values and a brush specified for the vertices, whereby said brush specifies a particular colour value for a particular pixel covered by the primitive. processing vertices of the processed primitive, the quadrilaterals, and the triangles to generate a position and coverage values for the vertices; and calculating modulated colors for the vertices based on respective coverage values and a brush specified for the vertices, whereby said brush specifies a particular colour value for a particular pixel covered by the primitive.