void AdjustVertexData(float fXOffset, float fYOffset)
{
std::vector<float> fNewData(ARRAY_COUNT(vertex_data));
memcpy(&fNewData[0], vertex_data, sizeof(vertex_data));
for(int iVertex = 0; iVertex < ARRAY_COUNT(vertex_data); iVertex += 4)
{
fNewData[iVertex] += fXOffset;
fNewData[iVertex + 1] += fYOffset;
}
glBindBuffer(GL_ARRAY_BUFFER, vertex_buffer_object);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertex_data), &fNewData[0]);
glDrawArrays(GL_TRIANGLES, 0, 3);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
void AdjustVertexData(float fXOffset, float fYOffset)
{
std::vector<float> fNewData(ARRAY_COUNT(vertexPositions));
memcpy(&fNewData[0], vertexPositions, sizeof(vertexPositions));
// Update x and y vertex coordinates, but skip z and w coordinates.
for(int iVertex = 0; iVertex < ARRAY_COUNT(vertexPositions); iVertex += 4)
{
fNewData[iVertex] += fXOffset;
fNewData[iVertex + 1] += fYOffset;
}
glBindBuffer(GL_ARRAY_BUFFER, positionBufferObject);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertexPositions), &fNewData[0]);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
void AdjustVertexData(float x, float z)
{
std::vector<float> fNewData(ARRAY_COUNT(vertices));
memcpy(&fNewData[0], vertices, sizeof(vertices));
for(int i = 24; i < 48; i += 3)
{
fNewData[i] += x;
fNewData[i + 2] += z;
}
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), &fNewData[0]);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
