Files
OpenSpace/modules/globebrowsing/rendering/clipmapgeometry.cpp
2016-04-12 13:44:28 -04:00

254 lines
9.1 KiB
C++

/*****************************************************************************************
* *
* OpenSpace *
* *
* Copyright (c) 2014-2016 *
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy of this *
* software and associated documentation files (the "Software"), to deal in the Software *
* without restriction, including without limitation the rights to use, copy, modify, *
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to *
* permit persons to whom the Software is furnished to do so, subject to the following *
* conditions: *
* *
* The above copyright notice and this permission notice shall be included in all copies *
* or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, *
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A *
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT *
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF *
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE *
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****************************************************************************************/
#include <modules/globebrowsing/rendering/clipmapgeometry.h>
#include <ghoul/opengl/ghoul_gl.h>
namespace {
const std::string _loggerCat = "ClipMapGeometry";
}
namespace openspace {
ClipMapGeometry::ClipMapGeometry(
unsigned int resolution,
Positions usePositions,
TextureCoordinates useTextures,
Normals useNormals)
: Geometry(CreateElements(resolution), usePositions, useTextures, useNormals)
, _resolution(resolution)
{
if(_useVertexPositions){
setVertexPositions(CreatePositions(_resolution));
}
if (_useTextureCoordinates) {
setVertexTextureCoordinates(CreateTextureCoordinates(_resolution));
}
if (_useVertexNormals) {
setVertexNormals(CreateNormals(_resolution));
}
}
ClipMapGeometry::~ClipMapGeometry()
{
}
const unsigned int ClipMapGeometry::resolution() const {
return _resolution;
}
size_t ClipMapGeometry::numElements(unsigned int resolution)
{
return resolution * resolution / 2 * 9;
}
size_t ClipMapGeometry::numVertices(unsigned int resolution)
{
return
(resolution + 1) * (resolution / 4 + 1) + // Bottom
(resolution / 4 + 1) * (resolution / 2 + 1) + // Left
(resolution / 4 + 1) * (resolution / 2 + 1) + // Right
(resolution + 1) * (resolution / 4 + 1); // Top
}
void ClipMapGeometry::validate(unsigned int resolution) {
ghoul_assert(resolution >= 8,
"Resolution must be at least 8. (" << resolution << ")");
ghoul_assert(resolution == pow(2, int(log2(resolution))),
"Resolution must be a power of 2. (" << resolution << ")");
}
std::vector<GLuint> ClipMapGeometry::CreateElements(unsigned int resolution) {
validate(resolution);
std::vector<GLuint> elements;
elements.reserve(numElements(resolution));
// x v01---v11 x ..
// | / |
// x v00---v10 x ..
//
// x x x x ..
// : : : :
unsigned int numVerticesBottom = (resolution + 1) * (resolution / 4 + 1);
unsigned int numVerticesLeft = (resolution / 4 + 1) * (resolution / 2 + 1);
unsigned int numVerticesRight = (resolution / 4 + 1) * (resolution / 2 + 1);
unsigned int numVerticesTop = (resolution + 1) * (resolution / 4 + 1);
// Build the bottom part of the clipmap geometry
for (unsigned int y = 0; y < resolution / 4; y++) {
for (unsigned int x = 0; x < resolution; x++) {
GLuint v00 = (y + 0) * (resolution + 1) + x + 0;
GLuint v10 = (y + 0) * (resolution + 1) + x + 1;
GLuint v01 = (y + 1) * (resolution + 1) + x + 0;
GLuint v11 = (y + 1) * (resolution + 1) + x + 1;
elements.push_back(v00);
elements.push_back(v10);
elements.push_back(v11);
elements.push_back(v00);
elements.push_back(v11);
elements.push_back(v01);
}
}
// Build the left part of the clipmap geometry
for (unsigned int y = 0; y < resolution / 2; y++) {
for (unsigned int x = 0; x < resolution / 4; x++) {
GLuint v00 = numVerticesBottom + (y + 0) * (resolution / 4 + 1) + x + 0;
GLuint v10 = numVerticesBottom + (y + 0) * (resolution / 4 + 1) + x + 1;
GLuint v01 = numVerticesBottom + (y + 1) * (resolution / 4 + 1) + x + 0;
GLuint v11 = numVerticesBottom + (y + 1) * (resolution / 4 + 1) + x + 1;
elements.push_back(v00);
elements.push_back(v10);
elements.push_back(v11);
elements.push_back(v00);
elements.push_back(v11);
elements.push_back(v01);
}
}
// Build the left part of the clipmap geometry
for (unsigned int y = 0; y < resolution / 2; y++) {
for (unsigned int x = 0; x < resolution / 4; x++) {
GLuint v00 = numVerticesBottom + numVerticesLeft + (y + 0) * (resolution / 4 + 1) + x + 0;
GLuint v10 = numVerticesBottom + numVerticesLeft + (y + 0) * (resolution / 4 + 1) + x + 1;
GLuint v01 = numVerticesBottom + numVerticesLeft + (y + 1) * (resolution / 4 + 1) + x + 0;
GLuint v11 = numVerticesBottom + numVerticesLeft + (y + 1) * (resolution / 4 + 1) + x + 1;
elements.push_back(v00);
elements.push_back(v10);
elements.push_back(v11);
elements.push_back(v00);
elements.push_back(v11);
elements.push_back(v01);
}
}
// Build the left part of the clipmap geometry
for (unsigned int y = 0; y < resolution / 4; y++) {
for (unsigned int x = 0; x < resolution; x++) {
GLuint v00 = numVerticesBottom + numVerticesLeft + numVerticesRight + (y + 0) * (resolution + 1) + x + 0;
GLuint v10 = numVerticesBottom + numVerticesLeft + numVerticesRight + (y + 0) * (resolution + 1) + x + 1;
GLuint v01 = numVerticesBottom + numVerticesLeft + numVerticesRight + (y + 1) * (resolution + 1) + x + 0;
GLuint v11 = numVerticesBottom + numVerticesLeft + numVerticesRight + (y + 1) * (resolution + 1) + x + 1;
elements.push_back(v00);
elements.push_back(v10);
elements.push_back(v11);
elements.push_back(v00);
elements.push_back(v11);
elements.push_back(v01);
}
}
return elements;
}
std::vector<glm::vec4> ClipMapGeometry::CreatePositions(unsigned int resolution)
{
validate(resolution);
std::vector<glm::vec4> positions;
positions.reserve(numVertices(resolution));
std::vector<glm::vec2> textureCoordinates = CreateTextureCoordinates(resolution);
// Copy from texture coordinates
for (unsigned int i = 0; i < textureCoordinates.size(); i++) {
positions.push_back(
glm::vec4(
textureCoordinates[i].x,
textureCoordinates[i].y,
0,
1));
}
return positions;
}
std::vector<glm::vec2> ClipMapGeometry::CreateTextureCoordinates(unsigned int resolution){
validate(resolution);
std::vector<glm::vec2> textureCoordinates;
textureCoordinates.reserve(numVertices(resolution));
// Build the bottom part of the clipmap geometry
for (unsigned int y = 0; y < resolution / 4 + 1; y++) {
for (unsigned int x = 0; x < resolution + 1; x++) {
textureCoordinates.push_back(glm::vec2(
static_cast<float>(x) / resolution,
static_cast<float>(y) / resolution));
}
}
// Build the left part of the clipmap geometry
for (unsigned int y = resolution / 4; y < 3 * resolution / 4 + 1; y++) {
for (unsigned int x = 0; x < resolution / 4 + 1; x++) {
float u = static_cast<float>(x) / resolution;
float v = static_cast<float>(y) / resolution;
textureCoordinates.push_back(glm::vec2(u, v));
}
}
// Build the right part of the clipmap geometry
for (unsigned int y = resolution / 4; y < 3 * resolution / 4 + 1; y++) {
for (unsigned int x = 3 * resolution / 4; x < resolution + 1; x++) {
float u = static_cast<float>(x) / resolution;
float v = static_cast<float>(y) / resolution;
textureCoordinates.push_back(glm::vec2(u, v));
}
}
// Build the top part of the clipmap geometry
for (unsigned int y = 3 * resolution / 4; y < resolution + 1; y++) {
for (unsigned int x = 0; x < resolution + 1; x++) {
textureCoordinates.push_back(glm::vec2(
static_cast<float>(x) / resolution,
static_cast<float>(y) / resolution));
}
}
return textureCoordinates;
}
std::vector<glm::vec3> ClipMapGeometry::CreateNormals(unsigned int resolution) {
validate(resolution);
std::vector<glm::vec3> normals;
normals.reserve(numVertices(resolution));
for (unsigned int y = 0; y < resolution + 1; y++) {
for (unsigned int x = 0; x < resolution + 1; x++) {
normals.push_back(glm::vec3(0, 0, 1));
}
}
return normals;
}
}// namespace openspace