GameCodingCompleteLinux/Source/GCC4/Graphics3D/Mesh.cpp

#include "../Unix/GameCodeStd.h"

#include "../GameCode4/GameCode.h"
#include "../ResourceCache/ResCache.h"
#include "OpenGLRenderer.h"
#include "Lights.h"
#include "Mesh.h"
// #include "Raycast.h"
#include "SceneNodes.h"


std::shared_ptr<IResourceLoader> CreateGlbMeshResourceLoader()
{
	return std::shared_ptr<IResourceLoader>(GCC_NEW GlbMeshResourceLoader());
}

unsigned int GlbMeshResourceLoader::VGetLoadedResourceSize(char *rawBuffer, unsigned int rawSize)
{
	// The raw data of the SDK Mesh file is needed by the CDXUTMesh class, so we're going to keep it around.
	return rawSize;
}

//
// SdkMeshResourceLoader::VLoadResource						- Chapter 16, page 561
//
bool GlbMeshResourceLoader::VLoadResource(char *rawBuffer, unsigned int rawSize, std::shared_ptr<ResHandle> handle)
{
	std::shared_ptr<OpenGLGlbMeshResourceExtraData> extra = std::shared_ptr<OpenGLGlbMeshResourceExtraData>(GCC_NEW OpenGLGlbMeshResourceExtraData());

	// load the mesh
	extra->m_pScene = aiImportFileFromMemory(rawBuffer, rawSize, 0, "glb");

	if (!extra->m_pScene || extra->m_pScene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !extra->m_pScene->mRootNode) {
	    GCC_ERROR(std::string("Failed to open scene file: ") + aiGetErrorString());
	    return false;
	}

	handle->SetExtra(std::shared_ptr<OpenGLGlbMeshResourceExtraData>(extra));

	return true;
}

OpenGLShaderMeshNode::OpenGLShaderMeshNode(const ActorId actorId,
	WeakBaseRenderComponentPtr renderComponent,
	std::string meshFileName,
	RenderPass renderPass,
	const glm::mat4 t)
: SceneNode(actorId, renderComponent, renderPass, t),
  m_vao(0),
  m_vbo(0),
  m_ebo(0),
  m_numIndices(0),
  m_numMeshes(0)
{
	m_meshFileName = meshFileName;
}

int OpenGLShaderMeshNode::VOnRestore(Scene *pScene)
{
	m_ShaderProgram.OnRestore(pScene);

	// Force the Mesh to reload
	Resource resource(m_meshFileName);
	std::shared_ptr<ResHandle> pResourceHandle = g_pApp->m_ResCache->GetHandle(&resource);
	std::shared_ptr<OpenGLGlbMeshResourceExtraData> extra = static_pointer_cast<OpenGLGlbMeshResourceExtraData>(pResourceHandle->GetExtra());

	for (int i = 0; i < m_numMeshes; i++) {
		glDeleteVertexArrays(1, &m_vao[i]);
		glDeleteBuffers(1, &m_vbo[i]);
		glDeleteBuffers(1, &m_ebo[i]);
	}

	if (m_vao) { delete[] m_vao; }
	if (m_vbo) { delete[] m_vbo; }
	if (m_ebo) { delete[] m_ebo; }
	if (m_numIndices) { delete[] m_numIndices; }
	if (m_numVerts) { delete[] m_numVerts; }

	m_numMeshes = extra->m_pScene->mNumMeshes;
	m_vao = GCC_NEW GLuint[m_numMeshes];
	m_vbo = GCC_NEW GLuint[m_numMeshes];
	m_ebo = GCC_NEW GLuint[m_numMeshes];
	m_numIndices = GCC_NEW size_t[m_numMeshes];
	m_numVerts = GCC_NEW size_t[m_numMeshes];

	for (int i = 0; i < extra->m_pScene->mNumMeshes; i++)
	{
		const aiMesh* p_AIMesh = extra->m_pScene->mMeshes[i];

		m_numVerts[i] = p_AIMesh->mNumVertices;
		VertexUnlitTextured *pVerts = GCC_NEW VertexUnlitTextured[m_numVerts[i]];

		GCC_ASSERT(pVerts && "Out of memory in OpenGLShaderMeshNode::VOnRestore");
		if (!pVerts)
			return 1;

		for (int j = 0; j < m_numVerts[i]; j++)
		{
			pVerts[j].Pos = glm::vec3(
				p_AIMesh->mVertices[j].x,
				p_AIMesh->mVertices[j].y,
				p_AIMesh->mVertices[j].z
			);
			pVerts[j].Normal = glm::vec3(
				p_AIMesh->mNormals[j].x,
				p_AIMesh->mNormals[j].y,
				p_AIMesh->mNormals[j].z
			);
			pVerts[j].Uv = glm::vec2(
				p_AIMesh->mTextureCoords[0][j].x,
				p_AIMesh->mTextureCoords[0][j].y
			);
		}

		m_numIndices[i] = p_AIMesh->mNumFaces * 3;
		GLuint *pIndices = GCC_NEW GLuint[m_numIndices[i]];

		GCC_ASSERT(pIndices && "Out of memory in OpenGLShaderMeshNode::VOnRestore");
		if (!pIndices)
		{
			delete[] pVerts;
			return 1;
		}

		GLuint *current = pIndices;
		for (int j = 0; j < p_AIMesh->mNumFaces; j++)
		{
			*(current + 0) = p_AIMesh->mFaces[j].mIndices[0];
			*(current + 1) = p_AIMesh->mFaces[j].mIndices[1];
			*(current + 2) = p_AIMesh->mFaces[j].mIndices[2];
			current += 3;
		}

		glCreateVertexArrays(1, &m_vao[i]);

		glCreateBuffers(1, &m_vbo[i]);
		glNamedBufferStorage(m_vbo[i], sizeof(VertexUnlitTextured) * m_numVerts[i], pVerts, 0);

		glVertexArrayVertexBuffer(m_vao[i], 0, m_vbo[i], 0, sizeof(VertexUnlitTextured));

		glEnableVertexArrayAttrib(m_vao[i], 0);
		glVertexArrayAttribFormat(m_vao[i], 0, 3, GL_FLOAT, GL_FALSE, 0);
		glVertexArrayAttribBinding(m_vao[i], 0, 0);

		glEnableVertexArrayAttrib(m_vao[i], 1);
		glVertexArrayAttribFormat(m_vao[i], 1, 3, GL_FLOAT, GL_FALSE, offsetof(VertexUnlitTextured, Normal));
		glVertexArrayAttribBinding(m_vao[i], 1, 0);

		glEnableVertexArrayAttrib(m_vao[i], 2);
		glVertexArrayAttribFormat(m_vao[i], 2, 2, GL_FLOAT, GL_FALSE,  offsetof(VertexUnlitTextured, Uv));
		glVertexArrayAttribBinding(m_vao[i], 2, 0);

		delete[] pVerts;

		glCreateBuffers(1, &m_ebo[i]);
		glNamedBufferStorage(m_ebo[i], sizeof(GLuint) * m_numIndices[i], pIndices, 0);
		glVertexArrayElementBuffer(m_vao[i], m_ebo[i]);

		delete[] pIndices;
	}


	// TODO (munnellg) - calcualte the bounding sphere here
	
	return 1;
}

int OpenGLShaderMeshNode::VRender(Scene *pScene)
{
	// GridRenderComponent* grc = static_cast<GridRenderComponent*>(m_RenderComponent);
	// m_ShaderProgram.SetTexture(grc->GetTextureResource());
	m_ShaderProgram.SetupRender(pScene, this);

	for (int i = 0; i < m_numMeshes; i++)
	{
		glBindVertexArray(m_vao[i]);
		glDrawElements(GL_TRIANGLES, m_numIndices[i], GL_UNSIGNED_INT, 0);
	}

	glBindVertexArray(0);
	return 0;
}