Glide view projection

The Glide renderer uses a fixed horizontal half-field tangent of 0.788 for world and book-menu rendering. The viewport is initialized to the full display.

For viewport width w, height h, and top-left corner (left, top), the normalized horizontal and vertical projection scales are:

sx = 1 / 0.788
sy = (w / h) / 0.788

The viewport center is (left + w/2, top + h/2). For camera-space coordinates (x, y, z), with positive Y down and positive Z forward, screen coordinates are:

screen_x = left + w/2 + (w/2) * x / (0.788 * z)
screen_y = top  + h/2 + (w/2) * y / (0.788 * z)

The equivalent vertical field of view is 2 * atan(0.788 * h / w), about 61.166 degrees at 640 by 480. The horizontal field of view stays fixed when the viewport aspect ratio changes.

The renderer subtracts its view position from world coordinates before applying the view matrix. Horizontal and vertical projection scales multiply the first and second rows of that matrix; the depth row remains unscaled.

See fog and clipping for depth ranges and book menu for its camera paths.