heightfield.h File Reference

Go to the source code of this file.

Functions
void	initHeightField ()
	Initialize the height field.
void	drawHeightField (float x, float y, int w, int h)
	Draw the height field.

---

Function Documentation

void drawHeightField (  float  x, float  y, int  w, int  h )

Draw the height field. The field is placed in the XY plane centered in (0,0,0). A transformation is set up so that the height field position (x,y) is moved into the origin, and w x h tiles around this position are drawn. Each tile covers g_cellsize square units in OpenGL coordinates. Definition at line 109 of file heightfield.cpp. References renderGroundQuad(), TEX_ROCK, TEX_SNOW, and texture(). Referenced by renderScene(). { // Automatic normals do not work correctly for a height field, // because there is no interaction between two adjacent strips. // In the solution, you will have to compute the normals of // the field yourself. glEnable( GL_AUTO_NORMAL ); // Enable the grass texture glBindTexture( GL_TEXTURE_2D, texture( TEX_SNOW )); glEnable( GL_TEXTURE_2D ); // Render ground once renderGroundQuad( w,h ); // Allow equal depth buffer values, otherwise the quad is not rendered // a second time glDepthFunc( GL_LEQUAL ); // Switch to the second texture glDisable( GL_TEXTURE_2D ); glBindTexture( GL_TEXTURE_2D, texture( TEX_ROCK )); glEnable( GL_TEXTURE_2D ); // Setup blending so that it blends with the framebuffer and the new // geometry using the value in the alpha channel as a weight glBlendEquation( GL_ADD ); glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ); // Switch on alpha blending, and render ground again glEnable( GL_BLEND ); renderGroundQuad( w,h ); // Reset rendering state glDepthFunc( GL_LESS ); glDisable( GL_BLEND ); glDisable( GL_TEXTURE_2D ); glDisable( GL_AUTO_NORMAL ); }

void initHeightField (   )

Initialize the height field. The field data is loaded as g_hfW*g_hfH continuous raw floats from the file. Definition at line 15 of file heightfield.cpp. References g_hf, g_hfH, g_hfW, g_strHeightFieldFile, and g_strResourceDir. Referenced by initGL(). { // Validate params int W = g_hfW; int H = g_hfH; assert( W>0 && W*H > 0 ); // Clear old data if (g_hf != NULL) { delete[] g_hf; } // Init new data g_hf = new float[W*H]; memset( g_hf,0, W*H*sizeof(float) ); // Read data from file char filename[500]; strcpy( filename, g_strResourceDir ); strcat( filename, g_strHeightFieldFile ); printf( "Reading height field %s\n", filename ); FILE *file = fopen( filename, "rb" ); assert( file != NULL ); int n; if ( (n=fread( g_hf, sizeof(float), W*H, file )) != W*H) { printf( "Error loading height field, only %i floats read.", n ); } else { printf( "read %i floats ... ", n ); } }

---