OpenGL-game/FrameBufferObject.cpp at main · ptch05/OpenGL-game · GitHub

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#include "Common.h"
#include "FrameBufferObject.h"

CFrameBufferObject::CFrameBufferObject()
	: m_iWidth(0),
	  m_iHeight(0),
	  m_uiFramebuffer(0),
	  m_uiColourTexture(0),
	  m_uiDepthTexture(0),
	  m_uiSampler(0)
{
}

CFrameBufferObject::~CFrameBufferObject()
{
	Release();
}

bool CFrameBufferObject::Create(int width, int height)
{
	if (m_uiFramebuffer != 0 || width <= 0 || height <= 0) {
		return false;
	}

	glGenFramebuffers(1, &m_uiFramebuffer);
	glBindFramebuffer(GL_FRAMEBUFFER, m_uiFramebuffer);

	glGenTextures(1, &m_uiColourTexture);
	glBindTexture(GL_TEXTURE_2D, m_uiColourTexture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_BGRA, GL_UNSIGNED_BYTE, NULL);
	glGenerateMipmap(GL_TEXTURE_2D);

	glGenSamplers(1, &m_uiSampler);
	SetSamplerObjectParameter(GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
	SetSamplerObjectParameter(GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	SetSamplerObjectParameter(GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	SetSamplerObjectParameter(GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

	glGenTextures(1, &m_uiDepthTexture);
	glBindTexture(GL_TEXTURE_2D, m_uiDepthTexture);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT24, width, height, 0, GL_DEPTH_COMPONENT, GL_UNSIGNED_BYTE, NULL);

	glFramebufferTexture(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, m_uiColourTexture, 0);
	glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, m_uiDepthTexture, 0);

	static const GLenum drawBuffers[] = { GL_COLOR_ATTACHMENT0 };
	glDrawBuffers(1, drawBuffers);

	m_iWidth = width;
	m_iHeight = height;

	bool complete = (glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	return complete;
}

void CFrameBufferObject::Bind(bool setFullViewport)
{
	glBindFramebuffer(GL_FRAMEBUFFER, m_uiFramebuffer);
	if (setFullViewport) {
		glViewport(0, 0, m_iWidth, m_iHeight);
	}

	glm::vec4 clearColour = glm::vec4(0.08f, 0.09f, 0.14f, 1.0f);
	float one = 1.0f;
	glClearBufferfv(GL_COLOR, 0, &clearColour.r);
	glClearBufferfv(GL_DEPTH, 0, &one);
}

void CFrameBufferObject::BindTexture(int textureUnit)
{
	glActiveTexture(GL_TEXTURE0 + textureUnit);
	glBindTexture(GL_TEXTURE_2D, m_uiColourTexture);
	glBindSampler(textureUnit, m_uiSampler);
	glGenerateMipmap(GL_TEXTURE_2D);
}

void CFrameBufferObject::BindDepth(int textureUnit)
{
	glActiveTexture(GL_TEXTURE0 + textureUnit);
	glBindTexture(GL_TEXTURE_2D, m_uiDepthTexture);
	glBindSampler(textureUnit, m_uiSampler);
}

void CFrameBufferObject::Release()
{
	if (m_uiFramebuffer) {
		glDeleteFramebuffers(1, &m_uiFramebuffer);
		m_uiFramebuffer = 0;
	}
	if (m_uiSampler) {
		glDeleteSamplers(1, &m_uiSampler);
		m_uiSampler = 0;
	}
	if (m_uiColourTexture) {
		glDeleteTextures(1, &m_uiColourTexture);
		m_uiColourTexture = 0;
	}
	if (m_uiDepthTexture) {
		glDeleteTextures(1, &m_uiDepthTexture);
		m_uiDepthTexture = 0;
	}

	m_iWidth = 0;
	m_iHeight = 0;
}

void CFrameBufferObject::SetSamplerObjectParameter(GLenum parameter, GLenum value)
{
	glSamplerParameteri(m_uiSampler, parameter, value);
}

void CFrameBufferObject::SetSamplerObjectParameterf(GLenum parameter, float value)
{
	glSamplerParameterf(m_uiSampler, parameter, value);
}

int CFrameBufferObject::GetWidth()
{
	return m_iWidth;
}

int CFrameBufferObject::GetHeight()
{
	return m_iHeight;
}