vcl/inc/opengl/VertexUtils.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  */
  10
  11 #ifndef INCLUDED_VCL_INC_OPENGL_VERTEXUTILS_H
  12 #define INCLUDED_VCL_INC_OPENGL_VERTEXUTILS_H
  13
  14 #include <basegfx/numeric/ftools.hxx>
  15 #include <epoxy/gl.h>
  16 #include <glm/gtx/norm.hpp>
  17 #include <tools/color.hxx>
  18 #include <vector>
  19
  20 namespace vcl::vertex
  21 {
  22
  23 template<GLenum TYPE>
  24 inline void addRectangle(std::vector<GLfloat>& rVertices, GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2);
  25
  26 template<>
  27 inline void addRectangle<GL_TRIANGLES>(std::vector<GLfloat>& rVertices, GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
  28 {
  29     rVertices.insert(rVertices.end(), {
  30         x1, y1, x2, y1, x1, y2,
  31         x1, y2, x2, y1, x2, y2
  32     });
  33 }
  34
  35 template<>
  36 inline void addRectangle<GL_TRIANGLE_FAN>(std::vector<GLfloat>& rVertices, GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
  37 {
  38     rVertices.insert(rVertices.end(), {
  39         x1, y2, x1, y1,
  40         x2, y1, x2, y2
  41     });
  42 }
  43
  44 inline void createColor(Color nColor, GLfloat fTransparency, GLubyte& nR, GLubyte& nG, GLubyte& nB, GLubyte& nA)
  45 {
  46     nR = nColor.GetRed();
  47     nG = nColor.GetGreen();
  48     nB = nColor.GetBlue();
  49     nA = (1.0f - fTransparency) * 255.0f;
  50 }
  51
  52 template<GLenum TYPE>
  53 inline void addQuadColors(std::vector<GLubyte>& rColors, Color nColor, GLfloat fTransparency);
  54
  55 template<>
  56 inline void addQuadColors<GL_TRIANGLES>(std::vector<GLubyte>& rColors, Color nColor, GLfloat fTransparency)
  57 {
  58     GLubyte nR, nG, nB, nA;
  59     createColor(nColor, fTransparency, nR, nG, nB, nA);
  60
  61     rColors.insert(rColors.end(), {
  62         nR, nG, nB, nA,
  63         nR, nG, nB, nA,
  64         nR, nG, nB, nA,
  65         nR, nG, nB, nA,
  66         nR, nG, nB, nA,
  67         nR, nG, nB, nA,
  68     });
  69 }
  70
  71 inline void addLineSegmentVertices(std::vector<GLfloat>& rVertices, std::vector<GLfloat>& rExtrusionVectors,
  72                                    glm::vec2 prevPoint, glm::vec2 prevExtrusionVector, GLfloat prevLength,
  73                                    glm::vec2 currPoint, glm::vec2 currExtrusionVector, GLfloat currLength)
  74 {
  75     rVertices.insert(rVertices.end(), {
  76         prevPoint.x, prevPoint.y,
  77         prevPoint.x, prevPoint.y,
  78         currPoint.x, currPoint.y,
  79         currPoint.x, currPoint.y,
  80         prevPoint.x, prevPoint.y,
  81         currPoint.x, currPoint.y,
  82     });
  83
  84     rExtrusionVectors.insert(rExtrusionVectors.end(), {
  85         -prevExtrusionVector.x, -prevExtrusionVector.y, -prevLength,
  86          prevExtrusionVector.x,  prevExtrusionVector.y,  prevLength,
  87         -currExtrusionVector.x, -currExtrusionVector.y, -currLength,
  88         -currExtrusionVector.x, -currExtrusionVector.y, -currLength,
  89          prevExtrusionVector.x,  prevExtrusionVector.y,  prevLength,
  90          currExtrusionVector.x,  currExtrusionVector.y,  currLength,
  91     });
  92 }
  93
  94 inline glm::vec2 normalize(const glm::vec2& vector)
  95 {
  96     if (glm::length(vector) > 0.0)
  97         return glm::normalize(vector);
  98     return vector;
  99 }
 100
 101 inline glm::vec2 perpendicular(const glm::vec2& vector)
 102 {
 103     return glm::vec2(-vector.y, vector.x);
 104 }
 105
 106 inline float lineVectorAngle(const glm::vec2& previous, const glm::vec2& next)
 107 {
 108     float angle = std::atan2(previous.x * next.y - previous.y * next.x,
 109                              previous.x * next.x + previous.y * next.y);
 110
 111     return F_PI - std::fabs(angle);
 112 }
 113
 114 } // end vcl::vertex
 115
 116 #endif // INCLUDED_VCL_INC_OPENGL_VERTEXUTILS_H
 117
 118 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */