maszyna/gl/cubemap.cpp

#include "stdafx.h"
#include "cubemap.h"

gl::cubemap::cubemap()
{
    glGenTextures(1, *this);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
}

gl::cubemap::~cubemap()
{
    glDeleteTextures(1, *this);
}

void gl::cubemap::alloc(GLint format, int width, int height, GLenum components, GLenum type) const
{
	glBindTexture(GL_TEXTURE_CUBE_MAP, *this);
	for (GLuint tgt = GL_TEXTURE_CUBE_MAP_POSITIVE_X; tgt <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z; tgt++)
		glTexImage2D(tgt, 0, format, width, height, 0, components, type, nullptr);

	// make the cubemap sample-complete with no mipmaps required.
	// generate_mipmaps() will later override MIN_FILTER once mips actually exist.
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

	glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
}

void gl::cubemap::bind(int unit) const
{
    glActiveTexture(unit);
    glBindTexture(GL_TEXTURE_CUBE_MAP, *this);
}

void gl::cubemap::generate_mipmaps() const
{
	glBindTexture(GL_TEXTURE_CUBE_MAP, *this);
	glGenerateMipmap(GL_TEXTURE_CUBE_MAP);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
}