charcoal/OpenGLEngine/BasicBatch.cpp

#include "BasicBatch.h"

namespace charcoal
{
	namespace builtin
	{
		void BasicBatch::setup_element_buffers()
		{
			glBindBuffer(GL_ARRAY_BUFFER, m_element_buffers[0]);
			glBufferData(GL_ARRAY_BUFFER, m_pose_elements.size() * sizeof(Poseable), NULL, GL_STREAM_DRAW);
		}

		void BasicBatch::setup_vao()
		{
			glBindBuffer(GL_ARRAY_BUFFER, m_vertex_vbo);
			glEnableVertexAttribArray(0);
			glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
			glBindBuffer(GL_ARRAY_BUFFER, m_element_buffers[0]);
			glEnableVertexAttribArray(1);
			glEnableVertexAttribArray(2);
			glEnableVertexAttribArray(3);
			glEnableVertexAttribArray(4);
			glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, sizeof(Poseable), (void*)(0 * sizeof(vec4)));
			glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, sizeof(Poseable), (void*)(1 * sizeof(vec4)));
			glVertexAttribPointer(3, 4, GL_FLOAT, GL_FALSE, sizeof(Poseable), (void*)(2 * sizeof(vec4)));
			glVertexAttribPointer(4, 4, GL_FLOAT, GL_FALSE, sizeof(Poseable), (void*)(3 * sizeof(vec4)));

			glVertexAttribDivisor(0, 0); // Send the mesh data once
			glVertexAttribDivisor(1, 1); // Send the offset data for each instance drawn
			glVertexAttribDivisor(2, 1); // Send the offset data for each instance drawn
			glVertexAttribDivisor(3, 1); // Send the offset data for each instance drawn
			glVertexAttribDivisor(4, 1); // Send the offset data for each instance drawn
		}

		void BasicBatch::update_element_buffers()
		{
			// TODO: There are probably better ways to do this. Should check with the old engine to see what I did there.
			glBindBuffer(GL_ARRAY_BUFFER, m_element_buffers[0]);
			glBufferData(GL_ARRAY_BUFFER, m_pose_elements.size() * sizeof(Poseable), NULL, GL_STREAM_DRAW);
			glBufferSubData(GL_ARRAY_BUFFER, 0, m_pose_elements.size() * sizeof(Poseable), m_pose_elements.data());
		}
	}
}