Jump to content

  • Log In with Google      Sign In   
  • Create Account

FREE SOFTWARE GIVEAWAY

We have 4 x Pro Licences (valued at $59 each) for 2d modular animation software Spriter to give away in this Thursday's GDNet Direct email newsletter.


Read more in this forum topic or make sure you're signed up (from the right-hand sidebar on the homepage) and read Thursday's newsletter to get in the running!


How could I optimise my 3D terrain algo?


Old topic!
Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.

  • You cannot reply to this topic
2 replies to this topic

#1 bobatefrei   Members   -  Reputation: 122

Like
Likes
Like

Posted 23 August 2001 - 05:24 AM

How could I optimise my 3D terrain algo? // Terrain3D.h: interface for the Terrain3D class. // ////////////////////////////////////////////////////////////////////// #if !defined(AFX_TERRAIN_H__72155EE2_65CA_11D5_B877_A51463FD174D__INCLUDED_) #define AFX_TERRAIN_H__72155EE2_65CA_11D5_B877_A51463FD174D__INCLUDED_ #include "bob.h" #include "FrustumCulling.h" #include "Repere3D.h" const MAP_SIZE = 256; #define MAP_INDEX(x, y) (((x)&255) + (((y)&255) << 8)) class Terrain3D { struct TerrainColor { uint8 r, g, b, a; }; public: Repere3D *camera; uint treeTexture; void SetBilinearFiltering(bool enable); Terrain3D(char *elevation_file, char *color_file, char *texture_file, real _y_scale = 10.0, real _espacement = 256.0); void Render(real y); void create_fractal(); real GetHeight(real pos_x, real pos_z); void Draw(uint x, uint z, uint w); void RenderNode(uint x, uint z, uint w); Terrain3D(); ~Terrain3D(); real espacement;//distance entre 2 points de la map real y_scale;//facteur d''altitude real max_y2;//hauteur maximale divisé par 2 uint min_size;//dimension minimale d''un bloc à découper real espacement_lod;// = espacement * lod; real elevations[MAP_SIZE * MAP_SIZE]; TerrainColor colors[MAP_SIZE * MAP_SIZE]; uint texID; uint lod; };//class Terrain3D #endif // !defined(AFX_TERRAIN_H__72155EE2_65CA_11D5_B877_A51463FD174D__INCLUDED_) // Terrain.cpp: implementation of the Terrain3D class. // ////////////////////////////////////////////////////////////////////// #include "Terrain.h" #include "Image2D.h" #include #include "Particule3D.h" #include "GameEngine.h" ////////////////////////////////////////////////////////////////////// // Construction/Destruction ////////////////////////////////////////////////////////////////////// Terrain3D::Terrain3D() { espacement = 128.0; min_size = 2; create_fractal(); texID = 0; Image2D *img = LoadImage2D("./fonds/terrain.tga"); if(LoadInTexture(img)) texID = img->texID; FreeImage2D(img); }//Terrain3D::Terrain3D() Terrain3D::~Terrain3D() { glDeleteTextures(1, &texID); } void Terrain3D::Draw(uint x, uint z, uint w) { Box3D box; box.x = real(x * espacement); box.y = max_y2;//128 * y_scale; box.z = real(z * espacement); box.w = real(w * espacement); box.p = real(w * espacement); box.h = max_y2;//128 * y_scale;; switch( BoxInFrustum(box) ) { case 2: RenderNode(x, z, w); break; case 0: break; case 1: if(w > min_size) { w = w >> 1; Draw(x + w, z + w, w); Draw(x - w, z + w, w); Draw(x + w, z - w, w); Draw(x - w, z - w, w); } else RenderNode(x, z, w); };//switch }//void Terrain3D::Draw() void Terrain3D::RenderNode(uint x_pos, uint z_pos, uint w) { uint x, z; /*Vector up, pos_vector; up.Set(0.0, 1.0, 0.0); glBindTexture(GL_TEXTURE_2D, treeTexture); pos_vector.Set(x_pos * espacement, elevations[MAP_INDEX(x_pos,z_pos)] + 50.0, z_pos * espacement); glColor3ub(255, 255, 255); glDisable(GL_CULL_FACE); glBlendFunc(GL_SRC_ALPHA, GL_ONE); glEnable(GL_BLEND); DrawBillboard(pos_vector, *camera, up, 100.0); glDisable(GL_BLEND); glEnable(GL_CULL_FACE); glBindTexture(GL_TEXTURE_2D, texID); */ /* //dessine les box de l''octree glDisable(GL_TEXTURE_2D); glPushMatrix(); glTranslate(x_pos * espacement, 128.0, z_pos * espacement); glColor3ub(x_pos % 255, z_pos % 256, 255); glutWireCube(w * espacement * 2); glPopMatrix(); glEnable(GL_TEXTURE_2D);*/ const real u1 = 0.0; const real v1 = 0.0; const real u2 = 1.0 * lod; const real v2 = 1.0 * lod; uint max_x = x_pos + w, max_z = z_pos + w; uint min_x = x_pos - w, min_z = z_pos - w; real x1, z1, x2, z2; real min_z1 = min_z * espacement; x1 = min_x * espacement; for(x = min_x; x < max_x; x+=lod, x1 += espacement_lod) { x2 = x1 + espacement_lod; z1 = min_z1; for(z = min_z; z < max_z; z+=lod, z1+=espacement_lod) { z2 = z1 + espacement_lod; glBegin(GL_TRIANGLE_STRIP); glColor3ub(colors[MAP_INDEX(x,z)].r, colors[MAP_INDEX(x,z)].g, colors[MAP_INDEX(x,z)].b); glTexCoord2f(u1, v1); glVertex3f(x1, elevations[MAP_INDEX(x,z)], z1); glColor3ub(colors[MAP_INDEX(x+lod,z)].r, colors[MAP_INDEX(x+lod,z)].g, colors[MAP_INDEX(x+lod,z)].b); glTexCoord2f(u2, v1); glVertex3f(x2, elevations[MAP_INDEX(x+lod,z)], z1); glColor3ub(colors[MAP_INDEX(x,z+lod)].r, colors[MAP_INDEX(x,z+lod)].g, colors[MAP_INDEX(x,z+lod)].b); glTexCoord2f(u1, v2); glVertex3f(x1, elevations[MAP_INDEX(x,z+lod)], z2); glColor3ub(colors[MAP_INDEX(x+lod,z+lod)].r, colors[MAP_INDEX(x+lod,z+lod)].g, colors[MAP_INDEX(x+lod,z+lod)].b); glTexCoord2f(u2, v2); glVertex3f(x2, elevations[MAP_INDEX(x+lod,z+lod)], z2); glEnd(); }//for z }//for x }//Terrain3D::RenderNode real Terrain3D::GetHeight(real pos_x, real pos_z) { real x0, x1, lx, lz, x, z, midpoint; int fx, fz; x = pos_x/espacement; z = pos_z/espacement; fx = (int)(x); fz = (int)(z); lx = x - fx; lz = z - fz; x0 = elevations[MAP_INDEX(fx,fz)] + (elevations[MAP_INDEX(fx,fz+1)] - elevations[MAP_INDEX(fx,fz)])*lz; x1 = elevations[MAP_INDEX(fx+1,fz)] + (elevations[MAP_INDEX(fx+1,fz+1)] - elevations[MAP_INDEX(fx+1,fz)])*lz; midpoint = x0 + (x1 - x0)*lx; return midpoint; }//real Terrain3D::GetHeight(real x, real y) void Terrain3D::create_fractal() { //int bsize, csize; int x, z;//, i; int r = 512; float gradient, shadow = 0.5; /*for(x=0;x<=MAP_SIZE;x++) for(z=0;z<=MAP_SIZE;z++) elevations[MAP_INDEX(x,z)] = 0; bsize = MAP_SIZE; for(i=0; i<8; i++) { for(x=0;x for(z=0;z elevations[MAP_INDEX(x,z)] += (rand()%(r+1)-r/2); if(i>4) r=r/2; csize = bsize/2; if(csize>0) { for(x=0; x { for(z=0; z { if( x < MAP_SIZE) elevations[MAP_INDEX(x+csize,z)] = (elevations[MAP_INDEX(x+bsize,z)]+elevations[MAP_INDEX(x,z)])/2; if( z < MAP_SIZE) elevations[MAP_INDEX(x,z+csize)] = (elevations[MAP_INDEX(x,z+bsize)]+elevations[MAP_INDEX(x,z)])/2; if ( x < MAP_SIZE && z < MAP_SIZE ) elevations[MAP_INDEX(x+csize,z+csize)] = ( elevations[MAP_INDEX(x,z)] + elevations[MAP_INDEX(x+bsize,z)] + elevations[MAP_INDEX(x,z+bsize)] + elevations[MAP_INDEX(x+bsize,z+bsize)]) / 4; }//for(z=0; z }//for(x=0; x }//if(csize>0) bsize = csize; }//for(i=0; i<8; i++) const real div_coef = 4.0; for(x=0; x { for(z=0; z { elevations[MAP_INDEX(x,z)] = elevations[MAP_INDEX(x,z)] + elevations[MAP_INDEX(x+1,z)] + elevations[MAP_INDEX(x+1,z+1)] + elevations[MAP_INDEX(x,z+1)]; elevations[MAP_INDEX(x,z)] /= div_coef; } } */ for(x=0; x<=MAP_SIZE; x++) { for(z=0; z<=MAP_SIZE; z++) { gradient = ((GLfloat) (elevations[MAP_INDEX(x,z)]-elevations[MAP_INDEX(x+1,z)])) / 100.0; if(elevations[MAP_INDEX(x,z)]>64) { if((elevations[MAP_INDEX(x,z)]-elevations[MAP_INDEX(x,z+1)])<8 && (elevations[MAP_INDEX(x,z)]-elevations[MAP_INDEX(x,z+1)])>-8 && (elevations[MAP_INDEX(x,z)]-elevations[MAP_INDEX(x+1,z)])<8 && (elevations[MAP_INDEX(x,z)]-elevations[MAP_INDEX(x+1,z)])>-8) { colors[MAP_INDEX(x,z)].g = (gradient + 0.75) * 255; colors[MAP_INDEX(x,z)].r = colors[MAP_INDEX(x,z)].g; colors[MAP_INDEX(x,z)].b = colors[MAP_INDEX(x,z)].g; } else { colors[MAP_INDEX(x,z)].r = (gradient + 0.75) * 255; colors[MAP_INDEX(x,z)].g = colors[MAP_INDEX(x,z)].r * 0.8; colors[MAP_INDEX(x,z)].b = colors[MAP_INDEX(x,z)].r * 0.5; } }//if(elevations[MAP_INDEX(x,z)]>64) else if(elevations[MAP_INDEX(x,z)]>0) { colors[MAP_INDEX(x,z)].g = (gradient + 0.75) * 255; colors[MAP_INDEX(x,z)].r = colors[MAP_INDEX(x,z)].g * 0.6; colors[MAP_INDEX(x,z)].b = 0.0; } else { colors[MAP_INDEX(x,z)].r = (gradient + 1.0) * 255; colors[MAP_INDEX(x,z)].g = colors[MAP_INDEX(x,z)].r * 0.75; colors[MAP_INDEX(x,z)].b = colors[MAP_INDEX(x,z)].r * 0.5; } }//for(z=0; z<=MAP_SIZE; z++) }//for(x=0; x<=MAP_SIZE; x++) }//Terrain3D::create_fractal void Terrain3D::Render(real y) { glEnable(GL_TEXTURE_2D); glBindTexture(GL_TEXTURE_2D, texID); //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT); //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT); glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_LINEAR_MIPMAP_LINEAR ); glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR ); glEnable(GL_DEPTH_TEST); glShadeModel(GL_SMOOTH); glEnable(GL_CULL_FACE); glCullFace(GL_FRONT); glEnable(GL_FOG); //bool fps_insuffisent = OutRun::currentFPS < 50.0; if(y > max_y2 * 256) lod = 32; else if(y > max_y2 * 128) lod = 16; else if(y > max_y2 * 64) lod = 8; else if(y > max_y2 * 32) lod = 4; else if(y > max_y2 * 16) lod = 2; else lod = 1; //lod = 4; if(lod > 4) min_size = lod; else min_size = 4; espacement_lod = espacement * lod; GetCurrentFrustum(); Draw(65536, 65536, 65536); glColor3ub(255, 255, 255); }//void Terrain3D::Render() Terrain3D::Terrain3D(char *elevation_file, char *color_file, char *texture_file, real _y_scale, real _espacement) { uint index=0; Image2D *img; y_scale = _y_scale * 4.0; max_y2 = 255.0 * y_scale / 2.0; espacement = _espacement; min_size = 2; lod = 1; texID = 0; img = LoadImage2D(texture_file); if(LoadInTexture(img, IMG_MIPMAP)) texID = img->texID; FreeImage2D(img); img = LoadImage2D(elevation_file); if(img) if( (img->w == MAP_SIZE) && (img->h == MAP_SIZE) && (img->bpp == 24)) for(uint x=0; x for(uint y=0; y { elevations[MAP_INDEX(x, y)] = real( img->pixel8[index] ) * y_scale; index += 3; } FreeImage2D(img); img = LoadImage2D(color_file); if(img) if( (img->w == MAP_SIZE) && (img->h == MAP_SIZE)) { index = 0; if(img->bpp == 32) for(uint x=0; x for(uint y=0; y { colors[MAP_INDEX(x, y)].r = img->pixel8[index]; colors[MAP_INDEX(x, y)].g = img->pixel8[index+1]; colors[MAP_INDEX(x, y)].b = img->pixel8[index+2]; colors[MAP_INDEX(x, y)].a = img->pixel8[index+3]; index+=4; } if(img->bpp == 24) for(uint x=0; x for(uint y=0; y { colors[MAP_INDEX(x, y)].r = img->pixel8[index]; colors[MAP_INDEX(x, y)].g = img->pixel8[index+1]; colors[MAP_INDEX(x, y)].b = img->pixel8[index+2]; index += 3; } }//if( (img->w == MAP_SIZE) && (img->h == MAP_SIZE) FreeImage2D(img); //DirectLoadTexture(treeTexture, "./terrains/tree.tga"); //create_fractal(); }//Terrain3D::Terrain3D(char *elevation_file, char *color_file, char *texture_file) void Terrain3D::SetBilinearFiltering(bool enable) { glBindTexture(GL_TEXTURE_2D, texID); if(enable) { glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST_MIPMAP_NEAREST); glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST_MIPMAP_NEAREST); } else { glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST_MIPMAP_NEAREST); glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST_MIPMAP_NEAREST); } }//void Terrain3D::SetBilinearFiltering(bool enable)

Sponsor:

#2 Anonymous Poster_Anonymous Poster_*   Guests   -  Reputation:

Likes

Posted 23 August 2001 - 03:20 PM

Well you can always optimize somewhat by replacing your * and / with bit shifting. Bit shifting is much faster than multiplication and division.

#3 bobatefrei   Members   -  Reputation: 122

Like
Likes
Like

Posted 23 August 2001 - 10:56 PM

Thanks, but I search algorythmic optimization. For example how can I add LOD without building a tree?




Old topic!
Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.



PARTNERS