Wed, 15 Jun 2022 12:17:29 +0300
Use Mapbox's ear clipping algorithm to handle drawing any simple polygon
/* * LDForge: LDraw parts authoring CAD * Copyright (C) 2020 Teemu Piippo * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "basicshaderprogram.h" BasicShader::BasicShader() : buffer{QOpenGLBuffer::VertexBuffer}, vertexShader{QOpenGLShader::Vertex}, fragmentShader{QOpenGLShader::Fragment} { } BasicShader::~BasicShader() { if (this->isInitialized) { this->teardown(); } } void BasicShader::initialize( const char* vertexShaderSource, const char* fragmentShaderSource, QOpenGLBuffer::UsagePattern usagePattern, const std::vector<GLAttributeSpec>& attributeSpecs) { if (not this->isInitialized) { this->initializeOpenGLFunctions(); this->isInitialized = true; this->program = std::make_unique<gl::ShaderProgram>(); gl::buildShaders(this->program.get(), vertexShaderSource, fragmentShaderSource); this->program->bind(); this->buffer.create(); this->buffer.bind(); this->buffer.setUsagePattern(usagePattern); this->vertexArrayObject.create(); this->vertexArrayObject.bind(); for (std::size_t i = 0; i < attributeSpecs.size(); ++i) { const auto& spec = attributeSpecs[i]; this->program->enableAttributeArray(i); this->program->setAttributeBuffer(i, spec.type, spec.offset, spec.tuplesize, spec.stride); } this->vertexArrayObject.release(); this->buffer.release(); this->program->release(); gl::checkForGLErrors(nullptr); } } void BasicShader::setMvpMatrix(const glm::mat4& newMvpMatrix) { this->setUniformMatrix("mvp", newMvpMatrix); } void BasicShader::setUniformMatrix(const char* name, const glm::mat4& value) { Q_ASSERT(this->isInitialized); this->program->bind(); this->program->setUniformMatrix(name, value); this->program->release(); gl::checkForGLErrors(nullptr); } void BasicShader::setUniformVector(const char* name, const glm::vec4& value) { Q_ASSERT(this->isInitialized); this->program->bind(); this->program->setUniformVector(name, value); this->program->release(); gl::checkForGLErrors(nullptr); } void BasicShader::bufferData(const void* data, std::size_t count, std::size_t size) { this->buffer.bind(); this->buffer.allocate(data, count * size); this->buffer.release(); this->vertexCount = count; } void BasicShader::draw(GLenum drawMode) { this->program->bind(); this->vertexArrayObject.bind(); glDrawArrays(drawMode, 0, this->vertexCount); this->vertexArrayObject.release(); this->program->release(); gl::checkForGLErrors(nullptr); } void BasicShader::teardown() { this->vertexArrayObject.destroy(); this->buffer.destroy(); this->program.reset(); }