buffer allocation

[demo] / src / opengl / mesh-gl.cc

diff --git a/src/opengl/mesh-gl.cc b/src/opengl/mesh-gl.cc
index 119d043..531ac78 100644 (file)
--- a/src/opengl/mesh-gl.cc
+++ b/src/opengl/mesh-gl.cc
@@ -1,4 +1,5 @@
 #include <GL/glew.h>
+#include <GL/gl.h>
 #include <gmath/gmath.h>
 
 #include "mesh-gl.h"
@@ -14,6 +15,9 @@ MeshGL::MeshGL()
 
        num_vertices = 0;
        num_indices = 0;
+
+       /* draw normals */
+       nvao = nvbo = 0;
 }
 
 MeshGL::MeshGL(const MeshGL &mesh)
@@ -29,6 +33,9 @@ MeshGL::MeshGL(const MeshGL &mesh)
        ibo = 0;
        vao = 0;
 
+       /* draw normals */
+       nvao = nvbo = 0;
+
        /*
         * if we set these to the actual
         * vertices.size() and indices.size()
@@ -62,10 +69,15 @@ MeshGL::~MeshGL()
 
        vertices.clear();
        normals.clear();
+       tex_coords.clear();
+       indices.clear();
 }
 
 void MeshGL::draw() const
 {
+       if(!vdata_valid) {
+               ((MeshGL *)this)->update_vertex_data();
+       }
        glBindVertexArray(vao);
 
        glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ibo);
@@ -75,9 +87,40 @@ void MeshGL::draw() const
        glBindVertexArray(0);
 }
 
-void MeshGL::update_vertex_data()
+void MeshGL::draw_normals(float scale) const
+{
+       if(!nvao) {
+               glGenVertexArrays(1, &nvao);
+               glBindVertexArray(nvao);
+
+               glGenBuffers(1, &nvbo);
+               glBindBuffer(GL_ARRAY_BUFFER, nvbo);
+
+               glBufferData(GL_ARRAY_BUFFER, normals.size() * sizeof(Vec3) * 2, 0, GL_STATIC_DRAW);
+               Vec3 *data = (Vec3 *)glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
+
+               for(size_t i = 0; i < normals.size(); i++) {
+                       *data++ = vertices[i];
+                       *data++ = vertices[i] + normals[i] * scale;
+               }
+               glUnmapBuffer(GL_ARRAY_BUFFER);
+
+               glVertexAttribPointer(MESH_VERTEX, 3, GL_FLOAT, GL_FALSE, sizeof(Vec3), 0);
+               glEnableVertexAttribArray(MESH_VERTEX);
+               glBindBuffer(GL_ARRAY_BUFFER, 0);
+       }
+       else {
+               glBindVertexArray(nvao);
+       }
+
+       glDrawArrays(GL_LINES, 0, normals.size() * 2);
+       glBindVertexArray(0);
+}
+
+bool MeshGL::update_vertex_data()
 {
        update_vbo();
+       return true;
 }
 
 void MeshGL::update_vbo()
@@ -163,6 +206,12 @@ void MeshGL::destroy_vbo()
        if(vbo_tex_coords)
                glDeleteBuffers(1, &vbo_tex_coords);
        if(ibo)
-               if(vao)
-                       glDeleteVertexArrays(1, &vao);
-}
\ No newline at end of file
+               glDeleteBuffers(1, &ibo);
+       if(vao)
+               glDeleteVertexArrays(1, &vao);
+
+       if(nvbo)
+               glDeleteBuffers(1, &nvbo);
+       if(nvao)
+               glDeleteVertexArrays(1, &nvao);
+}