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
  21 {
  22 namespace vertex
  23 {
  24
  25 template<GLenum TYPE>
  26 inline void addRectangle(std::vector<GLfloat>& rVertices, GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2);
  27
  28 template<>
  29 inline void addRectangle<GL_TRIANGLES>(std::vector<GLfloat>& rVertices, GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
  30 {
  31     rVertices.insert(rVertices.end(), {
  32         x1, y1, x2, y1, x1, y2,
  33         x1, y2, x2, y1, x2, y2
  34     });
  35 }
  36
  37 template<>
  38 inline void addRectangle<GL_TRIANGLE_FAN>(std::vector<GLfloat>& rVertices, GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2)
  39 {
  40     rVertices.insert(rVertices.end(), {
  41         x1, y2, x1, y1,
  42         x2, y1, x2, y2
  43     });
  44 }
  45
  46 inline void createColor(Color nColor, GLfloat fTransparency, GLubyte& nR, GLubyte& nG, GLubyte& nB, GLubyte& nA)
  47 {
  48     nR = nColor.GetRed();
  49     nG = nColor.GetGreen();
  50     nB = nColor.GetBlue();
  51     nA = (1.0f - fTransparency) * 255.0f;
  52 }
  53
  54 template<GLenum TYPE>
  55 inline void addQuadColors(std::vector<GLubyte>& rColors, Color nColor, GLfloat fTransparency);
  56
  57 template<>
  58 inline void addQuadColors<GL_TRIANGLES>(std::vector<GLubyte>& rColors, Color nColor, GLfloat fTransparency)
  59 {
  60     GLubyte nR, nG, nB, nA;
  61     createColor(nColor, fTransparency, nR, nG, nB, nA);
  62
  63     rColors.insert(rColors.end(), {
  64         nR, nG, nB, nA,
  65         nR, nG, nB, nA,
  66         nR, nG, nB, nA,
  67         nR, nG, nB, nA,
  68         nR, nG, nB, nA,
  69         nR, nG, nB, nA,
  70     });
  71 }
  72
  73 inline void addLineSegmentVertices(std::vector<GLfloat>& rVertices, std::vector<GLfloat>& rExtrusionVectors,
  74                                    glm::vec2 prevPoint, glm::vec2 prevExtrusionVector, GLfloat prevLength,
  75                                    glm::vec2 currPoint, glm::vec2 currExtrusionVector, GLfloat currLength)
  76 {
  77     rVertices.insert(rVertices.end(), {
  78         prevPoint.x, prevPoint.y,
  79         prevPoint.x, prevPoint.y,
  80         currPoint.x, currPoint.y,
  81         currPoint.x, currPoint.y,
  82         prevPoint.x, prevPoint.y,
  83         currPoint.x, currPoint.y,
  84     });
  85
  86     rExtrusionVectors.insert(rExtrusionVectors.end(), {
  87         -prevExtrusionVector.x, -prevExtrusionVector.y, -prevLength,
  88          prevExtrusionVector.x,  prevExtrusionVector.y,  prevLength,
  89         -currExtrusionVector.x, -currExtrusionVector.y, -currLength,
  90         -currExtrusionVector.x, -currExtrusionVector.y, -currLength,
  91          prevExtrusionVector.x,  prevExtrusionVector.y,  prevLength,
  92          currExtrusionVector.x,  currExtrusionVector.y,  currLength,
  93     });
  94 }
  95
  96 inline glm::vec2 normalize(const glm::vec2& vector)
  97 {
  98     if (glm::length(vector) > 0.0)
  99         return glm::normalize(vector);
 100     return vector;
 101 }
 102
 103 inline glm::vec2 perpendicular(const glm::vec2& vector)
 104 {
 105     return glm::vec2(-vector.y, vector.x);
 106 }
 107
 108 inline float lineVectorAngle(const glm::vec2& previous, const glm::vec2& next)
 109 {
 110     float angle = std::atan2(previous.x * next.y - previous.y * next.x,
 111                              previous.x * next.x + previous.y * next.y);
 112
 113     return F_PI - std::fabs(angle);
 114 }
 115
 116 }} // end vcl::vertex
 117
 118 #endif // INCLUDED_VCL_INC_OPENGL_VERTEXUTILS_H
 119
 120 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */