Graphics Reference
In-Depth Information
Figure 14-14
Terrain Rendered with Vertex Texture Fetch
The code in Example 14-22 generates a square triangle grid that we use as
the base terrain.
Example 14-22
Terrain Rendering Flat Grid Generation
int ESUTIL_API esGenSquareGrid ( int size, GLfloat **vertices,
GLuint **indices )
{
int i, j;
int numIndices = (size−1) * (size−1) * 2 * 3;
// Allocate memory for buffers
if ( vertices != NULL )
{
int numVertices = size * size;
float stepSize = (float) size − 1;
*vertices =
malloc ( sizeof(GLfloat) * 3 * numVertices );
for ( i = 0; i < size; ++i ) // row
{
for ( j = 0; j < size; ++j ) // column
{
(*vertices)[ 3 * (j + i*size) ] = i / stepSize;
(*vertices)[ 3 * (j + i*size) + 1 ] = j / stepSize;
(*vertices)[ 3 * (j + i*size) + 2 ] = 0.0f;
}
}
}
(continues)
