Draw.cpp

#include "Draw.h"
#include "./include/glad.h"
#include <iostream>

static GLenum DrawModeToGLEnum(DrawMode input) {
	switch (input) {
	case DrawMode::Points: return GL_POINTS;
		break;
	case DrawMode::LineStrip: return GL_LINE_STRIP;
		break;
	case DrawMode::LineLoop: return GL_LINE_LOOP;
		break;
	case DrawMode::Lines: return GL_LINES;
		break;
	case DrawMode::Triangles: return GL_TRIANGLES;
		break;
	case DrawMode::TriangleStrip: return GL_TRIANGLE_STRIP;
		break;
	case DrawMode::TriangleFan: return GL_TRIANGLE_FAN;
		break;
	}
	std::cout << "DrawModeToGLEnum unreachable code hint \n";
	return 0;
}

void Draw(IndexBuffer& inIndexBuffer, DrawMode mode) {
	unsigned int handle = inIndexBuffer.GetHandle();
	unsigned int numIndices = inIndexBuffer.Count();

	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, handle);
	glDrawElements(DrawModeToGLEnum(mode), numIndices, GL_UNSIGNED_INT, 0);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}

void Draw(unsigned int vertexCount, DrawMode mode) {
	glDrawArrays(DrawModeToGLEnum(mode), 0, vertexCount);
}

void DrawInstanced(IndexBuffer& inIndexBuffer, DrawMode mode, unsigned int instanceCount) {
	unsigned int handle = inIndexBuffer.GetHandle();
	unsigned int numIndices = inIndexBuffer.Count();

	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, handle);
	glDrawElementsInstanced(DrawModeToGLEnum(mode), numIndices, GL_UNSIGNED_INT, 0, instanceCount);
	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}

void DrawInstanced(unsigned int vertexCount, DrawMode mode, unsigned int numInstances) {
	glDrawArraysInstanced(DrawModeToGLEnum(mode), 0, vertexCount, numInstances);
}