TopoToucher

TopoToucher is a heightmap sandbox program for linux written in C++ with OpenGL. This was written using OpenGL, FreeGLUT, GLM, and helper libraries written by Mike Bailey. I have a writeup about this project on my website

Gallary

Building

Dependencies

• g++
• make
• OpenGL
• GLEW

Build

make

Run

./TopoToucher [VERT_RESOLUTION]

• VERT_RESOLUTION: Number of vertexes across the square in each direction. Default 100.

Note that even numbers will not have a center vertex and the start position will be rounded down and appear off-center towards (0,0)

Using

Controls

All keyboard controls are caps-agnostic.

Q : Quit Program

E : Cycle Rolloff Functions

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W : Push Vertex(es) Up

S : Push Vertex(es) Down

A : Decrease Influence Radius

D : Increase Influence Radius

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H : Move Cursor Left

J : Move Cursor Forward

K : Move Cursor Backward

L : Move Cursor Right

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L-CLK : Hold to Orbit

Scroll : Zoom in/out

R-CLK : Context Menu

• Axis : Enable/Disable center context axis
• Axis Colors : Change color of center context axis
• Depth Cue : Add additional depth-based darkening
• Projection : Change between Orthographic and Perspective views
• Reset : Reset all values including the heightmap, camera position, and all values above
• Debug : Enables debug logging to console
• Quit : Close the program. Same as Q

Rolloff Functions

An image of the currently implemented falloff equations is shown above. You can go to the interactive Desmos graph by clicking on the image or clicking here. The x value represents the distance from the currently selected vertex, and the y value represents the value to be added/subtracted from that vertex. In TopoToucher, the currently selected rolloff function can be found in white in the bottom left corner of the screen.

Lighting

TopoToucher uses a small ambient light, and an orbiting sun lamp to show variation in topography. No user input is required to utilize these lights, and the sun orbits automatically.

There is the option of enabling Depth Cue, using the right click context menu. Turning on Depth Cue enables some OpenGL Fog (whose parameters are defined as constants at the start of main.cpp) which darkens the scene a bit, but will make your angles a bit more prominent. Below are two images showing a map with depth cue turned off (left, default) and turned on (right).

Code

The base code for this program is stored in /main.cpp. Global variables are defined at the top of the file. Functions of note include:

• Display : Builds the heightmap mesh from the global array Heights, then draws everything to the screen
• MoveVert : Modifies the Heights array to influence vertexes on and around CurrentIndex, based on the variable Rolloff, which is an index of Rolloffs enumerator
• Keyboard : Handles keyboard interrupts
• InitMenus : Configures the right click context menu