From eb9369ff236d4be52fe5c1e4d2331007b54f7177 Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sun, 31 Jan 2021 13:54:54 +0000
Subject: Create mesh direct from vertices and indices

---
 gfx/models/mesh.cpp | 36 +++++++++++++++++++++---------------
 gfx/models/mesh.h   |  3 ++-
 2 files changed, 23 insertions(+), 16 deletions(-)

(limited to 'gfx')

diff --git a/gfx/models/mesh.cpp b/gfx/models/mesh.cpp
index 967f3fd..90de8db 100644
--- a/gfx/models/mesh.cpp
+++ b/gfx/models/mesh.cpp
@@ -1,7 +1,6 @@
 #include "mesh.h"
 #include "obj_loader.h"
 #include "vertex.hpp"
-#include <glm/glm.hpp>
 #include <memory>
 #include <vector>
 
@@ -39,23 +38,30 @@ Mesh::Mesh(const IndexedModel & model) :
 	glBindVertexArray(0);
 }
 
-Mesh::Mesh(Vertex * vertices, unsigned int numVertices, unsigned int * indices, unsigned int numIndices) :
-	Mesh {[vertices, numVertices, indices, numIndices]() {
-		IndexedModel model;
+Mesh::Mesh(std::span<Vertex> vertices, std::span<unsigned int> indices) :
+	m_vertexArrayObject {}, m_vertexArrayBuffers {}, m_numIndices {indices.size()}
+{
+	glGenVertexArrays(1, &m_vertexArrayObject);
+	glBindVertexArray(m_vertexArrayObject);
 
-		for (unsigned int i = 0; i < numVertices; i++) {
-			model.positions.push_back(vertices[i].pos);
-			model.texCoords.push_back(vertices[i].texCoord);
-			model.normals.push_back(vertices[i].normal);
-		}
+	glGenBuffers(2, m_vertexArrayBuffers.data());
 
-		for (unsigned int i = 0; i < numIndices; i++) {
-			model.indices.push_back(indices[i]);
-		}
+	glBindBuffer(GL_ARRAY_BUFFER, m_vertexArrayBuffers[0]);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex) * vertices.size(), vertices.data(), GL_STATIC_DRAW);
 
-		return model;
-	}()}
-{
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)offsetof(Vertex, pos));
+
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)offsetof(Vertex, texCoord));
+
+	glEnableVertexAttribArray(2);
+	glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)offsetof(Vertex, normal));
+
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, m_vertexArrayBuffers[1]);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices[0]) * indices.size(), indices.data(), GL_STATIC_DRAW);
+
+	glBindVertexArray(0);
 }
 
 Mesh::~Mesh()
diff --git a/gfx/models/mesh.h b/gfx/models/mesh.h
index 6dc5c32..e955644 100644
--- a/gfx/models/mesh.h
+++ b/gfx/models/mesh.h
@@ -4,6 +4,7 @@
 #include <GL/glew.h>
 #include <array>
 #include <cstddef>
+#include <span>
 #include <special_members.hpp>
 #include <string>
 
@@ -16,7 +17,7 @@ class Mesh {
 public:
 	explicit Mesh(const std::string & fileName);
 	explicit Mesh(const IndexedModel & model);
-	Mesh(Vertex * vertices, unsigned int numVertices, unsigned int * indices, unsigned int numIndices);
+	Mesh(std::span<Vertex> vertices, std::span<unsigned int> indices);
 	virtual ~Mesh();
 
 	NO_COPY(Mesh);
-- 
cgit v1.2.3