Startup presentation

Glide startup presents the active Glide implementation’s 3dfx splash, system/STARTUP2.GXA, then the book-style main menu. The splash is supplied by Glide, rather than by a Redguard movie file.

The New Game introduction is separate from this startup sequence. The title image is a single 640×480 frame. The original also draws small version and loading labels along its bottom edge.

Title labels

The title redraw selects the [system] gui_low_font entry from SYSTEM.INI. The GOG configuration points to fonts\\arialvb.fnt, a 9-pixel line-height font. The version label starts at (10,467) in RGB (32,32,32). Its format is Version %s.%s; the GOG release displays Version 1.0.1.0. Loading text is right-aligned to (630,467) in RGB (50,0,0). The map-registration stage supplies Loading Map %d. Sound preparation supplies Loading Sound.

Glyph bitmaps use their FNT left and top offsets. Each active character advances by its bitmap width plus one pixel. Space additionally advances by the width of the next glyph, the exclamation mark. Text-width measurement uses the same advances. These rules follow the title caller, text-width routine, and glyph-drawing path, independently of the font-file fields.

Splash variants

The full DOS glide2x_emu.ovl contains the older “3Dfx Interactive” logo on a white shield with blue and yellow borders. DOSBox-X Voodoo emulation runs this hardware-facing overlay and displays that animation.

The small DOS forwarding glide2x.ovl routes Glide calls to a host Windows wrapper. A wrapper using 3DfxSpl2.dll displays the later metallic lowercase 3dfx logo with an orange swoosh. The DLL’s 1999 branding postdates Redguard’s 1998 release. The GOG install includes both paths, so the active Glide implementation determines the splash. OpenGLide’s NoSplash and nGlide’s splash setting can also suppress driver startup presentation.

The DLL resource contains authored geometry, textures and commands for the later animation. The older animation remains available in the DOS overlay tables. These assets are separate from the Smacker New Game introduction.

Windows splash rendering

The DLL command stream supplies the camera, horizontal FOV, model transforms, material selection, and positional light. Multiply each model transform by the camera transform. Negate the resulting position and normal Z components, then normalize the normal. Projection uses the same scale on both axes, W / (2*tan(horizontal_fov/2)), and centers the viewport. The Glide origin is lower-left.

Geometry without flag bit 3 uses its authored UV pairs multiplied by 256. Geometry with that flag intersects the positive normal ray from the transformed vertex with a sphere of radius 400 centered at the view origin. The far intersection supplies S/T as (intersection.xy/400 + 1) * 204.8. Texture coordinates are perspective-correct. Textures use bilinear filtering.

For a normalized light direction L and normal N, diffuse is max(dot(N,L),0). The reflection direction is normalize(2*N*dot(N,L)-L). Specular is the eighth power of its nonnegative dot product with the normalized view direction. The view direction is the camera matrix’s third column with negated Z.

One lighting contribution uses direction (1,1,-1)/sqrt(3); the other uses the authored positional light minus the transformed vertex. Beyond a squared light distance of 4,000,000, the positional contribution is multiplied by (4,000,000/distance_squared)^4. Vertex RGB, in byte units, is:

RGB = clamp(255*positional_RGB*(positional_diffuse + positional_specular)
            + 255*(directional_diffuse + directional_specular) + 16, 0, 255)

During full playback, texture RGB multiplies interpolated vertex RGB. Constant material RGB is used by the single-frame drawing path, which bypasses textures. That diagnostic path therefore differs from full animation playback. Triangles cull by winding. Polygon edges are drawn through Glide’s antialiased line path after pending edge groups flush.

The timed-frame command overlays black before presenting. Its alpha is 1 for frame counters below 24, then 1-(frame-24)/8 for counters 24 through 31. Frames from counter 32 onward have no overlay. After presenting, both color and depth are cleared for the next frame. The final untimed redraws precede a fade of 2*frame_rate swaps, each waiting two refresh intervals. Fade alpha starts at zero, then uses the truncated byte value 102*step/(2*frame_rate). The black overlay accumulates separately on the two alternating buffers.

DOS overlay splash

The Glide splash tables contain the geometry, textures, and authored transforms. No executable code needs to run to extract or display the animation.

The full animation renders authored frames 1 through 74. Frame zero is not part of that playback. Each mesh’s position uses its column-major affine matrix; its normal uses the linear part without translation or normalization.

With a viewport of width W and height H, a transformed point (x,y,z) maps to:

screen_x = (x/z) * 0.75W + W/2
screen_y = (y/z) * H + H/2

The splash uses a lower-left origin. Texture coordinates are perspective correct, with 256 S units across the longest texture dimension. A 2:1 texture uses 128 T units. The renderer enables bilinear filtering and selects the nearest mip level.

Vertex lighting uses L = (-0.57735, -0.57735, -0.57735) and brightness = (dot(L, transformed_normal) + 1) / 2.

Highlight S/T coordinates are (128 + 128*normal.x, 128 + 128*normal.y). Material 1’s intensity-factor table contains 0.125 in each channel, but the texture-only color combiner bypasses that factor during full animation.

The outer shield and shield render first without depth writes. A projected shadow multiplies their existing colors, with fog disabled for that pass. The logo then renders with depth testing and writes enabled; its material-0 highlight adds to the existing logo color. Triangles use winding culling and face-selected edge antialiasing.

The fade is black fog on geometry. With 75 frames, fade-in spans the first 22 frames: before frame 22, visibility is the truncated 8-bit value of 255*(frame+1)/22, divided by 255. After frame 60, visibility is the truncated 8-bit value of 255*(75-frame)/15, divided by 255. Other frames have full visibility. The background remains black.

Projected shadow

The shadow quad’s object-space corners are (-280,0,-160), (-280,0,150), (280,0,150), and (280,0,-160), with S/T pairs (10.5,127.5), (10.5,0.5), (255,0.5), and (255,127.5). Transform these corners with the logo matrix. The light is (5,300,shield_translation_z - 1500); project the light-to-corner lines onto z = shield_translation_z - 26. Screen projection is the same as for geometry. Two triangles cover the quad, submitted in both windings.

S and T are stored multiplied by the projected point’s reciprocal Z. The per-TMU reciprocal-W field additionally contains the light-to-projected-point distance divided by Z.

External references

• Glide splash renderer
• Glide splash data declarations

World loading screen

World entry uses the destination’s WORLD.INI world_flash_filename GXA. An archive with several frames supplies a randomly selected background; a single-frame archive uses its only frame. The full-screen picture uses its own palette. New-game entry uses start_world and start_marker from the [world] section.

At the 640 by 480 logical viewport, the progress bar starts at (32,448), is 576 pixels wide and 6 pixels high. Its background is black and its fill is VGA RGB (63,0,0). Fill width is the nearest-integer product of the bar width and the completed fraction. The displayed integer percentage also rounds to nearest. Percentage updates advance monotonically; a zero-percent update does not draw the bar or label.

The percentage label uses FONTS/REDSEL.FNT at (32,451), with foreground alpha 255 and shadow alpha 180. The ordinary label is %d%%; debug output can include world indices before it. These are world-entry loading visuals, separate from the startup title’s small bottom-edge labels.