nuclear@5: #include <stdio.h>
nuclear@5: #include <assert.h>
nuclear@5: #include "opengl.h"
nuclear@5: #include <imago2.h>
nuclear@4: #include "terrain.h"
nuclear@5: #include "datapath.h"
nuclear@5: 
nuclear@5: using namespace tinyxml2;
nuclear@4: 
nuclear@4: Terrain::Terrain()
nuclear@4: {
nuclear@4: 	root = 0;
nuclear@5: 	size = 2;
nuclear@4: }
nuclear@4: 
nuclear@4: Terrain::~Terrain()
nuclear@4: {
nuclear@4: 	delete root;
nuclear@4: }
nuclear@4: 
nuclear@5: bool Terrain::load(XMLElement *xelem)
nuclear@5: {
nuclear@5: 	root = new TerrainNode;
nuclear@5: 	return root->load(xelem);
nuclear@5: }
nuclear@5: 
nuclear@5: void Terrain::set_size(float sz)
nuclear@5: {
nuclear@5: 	size = sz;
nuclear@5: }
nuclear@5: 
nuclear@4: float Terrain::get_height(float x, float y) const
nuclear@4: {
nuclear@4: 	return root->get_height(x, y);
nuclear@4: }
nuclear@4: 
nuclear@5: void Terrain::draw() const
nuclear@5: {
nuclear@5: 	root->draw(0, 0, size, size);
nuclear@5: }
nuclear@5: 
nuclear@5: 
nuclear@5: // ---- terrain quadtree node ----
nuclear@4: 
nuclear@4: TerrainNode::TerrainNode()
nuclear@4: {
nuclear@5: 	map_xsz = map_ysz = 0;
nuclear@5: 	map_scale = 1.0;
nuclear@5: 	hmap = 0;
nuclear@5: 	child[0] = child[1] = child[2] = child[3] = 0;
nuclear@4: }
nuclear@4: 
nuclear@4: TerrainNode::~TerrainNode()
nuclear@4: {
nuclear@4: 	for(auto c : child) {
nuclear@4: 		delete c;
nuclear@4: 	}
nuclear@5: 	img_free_pixels(hmap);
nuclear@5: }
nuclear@5: 
nuclear@5: bool TerrainNode::load(XMLElement *xelem)
nuclear@5: {
nuclear@5: 	XMLNode *node = xelem->FirstChild();
nuclear@5: 	do {
nuclear@5: 		XMLElement *celem = node->ToElement();
nuclear@5: 		if(!celem) {
nuclear@5: 			fprintf(stderr, "ignoring non-element child of <terrain>\n");
nuclear@5: 			continue;
nuclear@5: 		}
nuclear@5: 
nuclear@5: 		const char *attr, *name = celem->Name();
nuclear@5: 
nuclear@5: 		if(strcmp(name, "terrain") == 0) {
nuclear@5: 			// child is a recursive terrain element
nuclear@5: 			int cidx = 0;
nuclear@5: 			if((attr = celem->Attribute("index"))) {
nuclear@5: 				if(celem->QueryIntAttribute("index", &cidx) != 0) {
nuclear@5: 					fprintf(stderr, "invalid index attribute in terrain: %s\n", attr);
nuclear@5: 					return false;
nuclear@5: 				}
nuclear@5: 			}
nuclear@5: 
nuclear@5: 			if(child[cidx]) {
nuclear@5: 				fprintf(stderr, "duplicate terrain child with index %d in terrain\n", cidx);
nuclear@5: 				return false;
nuclear@5: 			}
nuclear@5: 
nuclear@5: 			child[cidx] = new TerrainNode;
nuclear@5: 			if(!child[cidx]->load(celem)) {
nuclear@5: 				return false;
nuclear@5: 			}
nuclear@5: 		} else if(strcmp(name, "map") == 0) {
nuclear@5: 			// child is an map of some kind
nuclear@5: 			// XXX for now we only care about heightmaps
nuclear@5: 
nuclear@5: 			if((attr = celem->Attribute("type")) && strcmp(attr, "height") != 0) {
nuclear@5: 				fprintf(stderr, "ignoring map of type %s in terrain\n", attr);
nuclear@5: 				continue;
nuclear@5: 			}
nuclear@5: 
nuclear@5: 			if((attr = celem->Attribute("file"))) {
nuclear@5: 				char fname[PATH_MAX];
nuclear@5: 
nuclear@5: 				if(!find_file(attr, fname)) {
nuclear@5: 					fprintf(stderr, "failed to locate map: %s\n", attr);
nuclear@5: 					return false;
nuclear@5: 				}
nuclear@5: 
nuclear@5: 				if(!load_heightmap(fname)) {
nuclear@5: 					fprintf(stderr, "failed to load map: %s\n", fname);
nuclear@5: 					return false;
nuclear@5: 				}
nuclear@5: 			} else {
nuclear@5: 				fprintf(stderr, "ignoring map without file attribute in terrain\n");
nuclear@5: 				continue;
nuclear@5: 			}
nuclear@5: 
nuclear@5: 			float val;
nuclear@5: 			if(celem->QueryFloatAttribute("scale", &val) == 0) {
nuclear@5: 				map_scale = val;
nuclear@5: 			}
nuclear@5: 		}
nuclear@5: 	} while((node = node->NextSibling()));
nuclear@5: 
nuclear@5: 	return true;
nuclear@5: }
nuclear@5: 
nuclear@5: 
nuclear@5: bool TerrainNode::load_heightmap(const char *fname)
nuclear@5: {
nuclear@5: 	img_free_pixels(hmap);
nuclear@5: 
nuclear@5: 	if(!(hmap = (unsigned char*)img_load_pixels(fname, &map_xsz, &map_ysz, IMG_FMT_GREY8))) {
nuclear@5: 		fprintf(stderr, "failed to load heightmap: %s\n", fname);
nuclear@5: 		return false;
nuclear@5: 	}
nuclear@5: 	return true;
nuclear@5: }
nuclear@5: 
nuclear@5: bool TerrainNode::is_leaf() const
nuclear@5: {
nuclear@5: 	if(!child[0]) {
nuclear@5: 		assert(!child[1] && !child[2] && !child[3]);
nuclear@5: 		return true;
nuclear@5: 	}
nuclear@5: 	return false;
nuclear@5: }
nuclear@5: 
nuclear@5: static float child_coord(float x)
nuclear@5: {
nuclear@5: 	return (x - 0.5) * 2;
nuclear@5: }
nuclear@5: 
nuclear@5: static int quadrant(float x, float y)
nuclear@5: {
nuclear@5: 	int xpos = x >= 0 ? 1 : 0;
nuclear@5: 	int ypos = y >= 0 ? 1 : 0;
nuclear@5: 	return ypos * 2 + xpos;
nuclear@4: }
nuclear@4: 
nuclear@4: TerrainNode *TerrainNode::get_child(float x, float y)
nuclear@4: {
nuclear@5: 	if(is_leaf()) {
nuclear@5: 		return this;
nuclear@5: 	}
nuclear@5: 
nuclear@5: 	int cidx = quadrant(x, y);
nuclear@5: 	int cx = child_coord(x);
nuclear@5: 	int cy = child_coord(y);
nuclear@5: 
nuclear@5: 	return child[cidx]->get_child(cx, cy);
nuclear@4: }
nuclear@4: 
nuclear@4: const TerrainNode *TerrainNode::get_child(float x, float y) const
nuclear@4: {
nuclear@5: 	return ((TerrainNode*)this)->get_child(x, y);
nuclear@4: }
nuclear@4: 
nuclear@4: float TerrainNode::get_height(float x, float y) const
nuclear@4: {
nuclear@5: 	if(is_leaf()) {
nuclear@5: 		int tx = (x * 0.5 + 0.5) * map_xsz;
nuclear@5: 		int ty = (y * 0.5 + 0.5) * map_ysz;
nuclear@5: 		assert(tx >= 0 && tx < map_xsz);
nuclear@5: 		assert(ty >= 0 && ty < map_ysz);
nuclear@5: 		return map_scale * hmap[ty * map_xsz + tx] / 255.0;
nuclear@5: 	}
nuclear@4: 
nuclear@5: 	int cidx = quadrant(x, y);
nuclear@5: 	int cx = child_coord(x);
nuclear@5: 	int cy = child_coord(y);
nuclear@5: 
nuclear@5: 	return child[cidx]->get_height(cx, cy);
nuclear@5: }
nuclear@5: 
nuclear@5: void TerrainNode::draw(float x, float y, float width, float height) const
nuclear@5: {
nuclear@5: 	static const float offset[][2] = {{-0.25, -0.25}, {0.25, -0.25}, {-0.25, 0.25}, {0.25, 0.25}};
nuclear@5: 
nuclear@5: 	if(!is_leaf()) {
nuclear@5: 		float half_w = width / 2.0;
nuclear@5: 		float half_h = height / 2.0;
nuclear@5: 
nuclear@5: 		for(int i=0; i<4; i++) {
nuclear@5: 			child[i]->draw(x + offset[i][0] * width, y + offset[i][1] * height, half_w, half_h);
nuclear@5: 		}
nuclear@5: 		return;
nuclear@4: 	}
nuclear@5: 
nuclear@5: 	float dx = width / map_xsz;
nuclear@5: 	float dy = height / map_ysz;
nuclear@5: 	unsigned char *hptr = hmap;
nuclear@5: 
nuclear@5: 	glBegin(GL_POINTS);
nuclear@5: 
nuclear@5: 	float verty = y - height / 2.0;
nuclear@5: 	for(int i=0; i<map_ysz; i++) {
nuclear@5: 
nuclear@5: 		float vertx = x - width / 2.0;
nuclear@5: 		for(int j=0; j<map_xsz; j++) {
nuclear@5: 			float height = map_scale * *hptr++ / 255.0;
nuclear@5: 
nuclear@5: 			glColor3f(height, 0, 1.0 - height);
nuclear@5: 			glVertex3f(vertx, height, verty);
nuclear@5: 
nuclear@5: 			vertx += dx;
nuclear@5: 		}
nuclear@5: 		verty += dy;
nuclear@5: 	}
nuclear@5: 	glEnd();
nuclear@4: }