Function glPixelZoom

glPixelZoom specifies values for the 𝐱 and 𝐲 zoom factors. During the execution of glDrawPixels or glCopyPixels, if (𝐱𝐫, 𝐲𝐫) is the current raster position, and a given element is in the 𝐦ᵗʰ and 𝐧ᵗʰ column of the pixel rectangle, then pixels whose centers are in the rectangle with corners at

(𝐱𝐫 + 𝐧⋅xfactor, 𝐲𝐫 + 𝐦⋅yfactor)

(𝐱𝐫 + (𝐧 + 1)⋅xfactor, 𝐲𝐫 + (𝐦 + 1)⋅yfactor)

are candidates for replacement. Any pixel whose center lies on the bottom or left edge of this rectangular region is also modified.

Pixel zoom factors are not limited to positive values. Negative zoom factors reflect the resulting image about the current raster position.

Summary

specify the pixel zoom factors

See

glPixelZoom