ApplicationUtility.cpp

#include <ApplicationUtility.h>
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

float lerp(float a, float b, float f)
{
	return a + f * (b - a);
}

unsigned int initQuad(float size, float dist) {
	unsigned int quadVAO, quadVBO;
	float quadVertices[] = {
		size,  1.0f, dist, 0.0f, 1.0f,
		size, size, dist, 0.0f, 0.0f,
		 1.0f,  1.0f, dist, 1.0f, 1.0f,
		 1.0f, size, dist, 1.0f, 0.0f,
	};
	glGenVertexArrays(1, &quadVAO);
	glGenBuffers(1, &quadVBO);
	glBindVertexArray(quadVAO);
	glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(quadVertices), &quadVertices, GL_STATIC_DRAW);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(1);
	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
	return quadVAO;
}


void renderQuad(unsigned int VAO) {
	glBindVertexArray(VAO);
	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
	glBindVertexArray(0);
}


unsigned int loadTexturePath(const char* path) {
	unsigned int texture;
	glGenTextures(1, &texture);
	glBindTexture(GL_TEXTURE_2D, texture);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	int width, height, nrChannels;
	stbi_set_flip_vertically_on_load(true);
	unsigned char* data = stbi_load(path, &width, &height, &nrChannels, 0);
	if (data)
	{
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
		glGenerateMipmap(GL_TEXTURE_2D);
	}
	else
	{
		std::cout << "Failed to load texture" << std::endl;
	}
	stbi_image_free(data);
	return texture;
}


unsigned int loadHDRIPath(const char* path) {
	stbi_set_flip_vertically_on_load(true);
	int width, height, nrComponents;
	float* data = stbi_loadf(path, &width, &height, &nrComponents, 0);
	unsigned int hdrTexture;
	if (data)
	{
		glGenTextures(1, &hdrTexture);
		glBindTexture(GL_TEXTURE_2D, hdrTexture);
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB16F, width, height, 0, GL_RGB, GL_FLOAT, data);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
		stbi_image_free(data);
	}
	else
	{
		std::cout << "Failed to load HDR image." << std::endl;
	}
	return hdrTexture;
}


unsigned int bindDepthMap(unsigned int FBO, int width, int height) {
	glBindFramebuffer(GL_FRAMEBUFFER, FBO);
	unsigned int depthMap;
	glGenTextures(1, &depthMap);
	glBindTexture(GL_TEXTURE_2D, depthMap);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, width, height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depthMap, 0);
	glDrawBuffer(GL_NONE);
	glReadBuffer(GL_NONE);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	return depthMap;
}


unsigned int bindStencilMap(unsigned int FBO, int width, int height) {
	glBindFramebuffer(GL_FRAMEBUFFER, FBO);
	unsigned int StencilMap;
	glGenTextures(1, &StencilMap);
	glBindTexture(GL_TEXTURE_2D, StencilMap);
	glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, width, height, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, StencilMap, 0);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	return StencilMap;
}


void attachRBOToBuffer(unsigned int FBO, int width, int height, GLenum component, GLenum attachment, unsigned int samples) {
	unsigned int rboDepth;
	glGenRenderbuffers(1, &rboDepth);
	glBindRenderbuffer(GL_RENDERBUFFER, rboDepth);
	if (samples <= 1) {
		glRenderbufferStorage(GL_RENDERBUFFER, component, width, height);
	}
	else {
		glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples, component, width, height);
	}
	glBindFramebuffer(GL_FRAMEBUFFER, FBO);
	glFramebufferRenderbuffer(GL_FRAMEBUFFER, attachment, GL_RENDERBUFFER, rboDepth);
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
		std::cout << "RBO_ATTACH Framebuffer not complete!" << std::endl;
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE)
		std::cout << "RBO_ATTACH MULTSAMPLE!" << std::endl;
	glBindFramebuffer(GL_FRAMEBUFFER, 0);

}

unsigned int genCubeMap(int width, int height, GLenum format, GLenum component) {
	unsigned int Cubemap;
	glGenTextures(1, &Cubemap);
	glBindTexture(GL_TEXTURE_CUBE_MAP, Cubemap);
	for (unsigned int i = 0; i < 6; ++i) {
		glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, format, width, height, 0, component, GL_FLOAT, NULL);
	}
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
	glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
	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);
	return Cubemap;
}


unsigned int bindCubeDepthMap(unsigned int FBO, int width, int height) {
	glBindFramebuffer(GL_FRAMEBUFFER, FBO);
	unsigned int depthCubemap = genCubeMap(width, height, GL_DEPTH_COMPONENT, GL_DEPTH_COMPONENT);
	glFramebufferTexture(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, depthCubemap, 0);
	glDrawBuffer(GL_NONE);
	glReadBuffer(GL_NONE);
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	return depthCubemap;
}


unsigned int bindColorBuffer(unsigned int FBO, int width, int height, GLenum attachment, GLint format, unsigned int samples, GLint option) {
	glBindFramebuffer(GL_FRAMEBUFFER, FBO);
	unsigned int colorBufferTexture;
	glGenTextures(1, &colorBufferTexture);
	if (samples <= 1) {
		glBindTexture(GL_TEXTURE_2D, colorBufferTexture);
		glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, GL_RGBA, GL_FLOAT, NULL);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, option);
		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, option);
		glFramebufferTexture2D(GL_FRAMEBUFFER, attachment, GL_TEXTURE_2D, colorBufferTexture, 0);
	}
	else {
		glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, colorBufferTexture);
		glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, format, width, height, GL_TRUE);
		glFramebufferTexture2D(GL_FRAMEBUFFER, attachment, GL_TEXTURE_2D_MULTISAMPLE, colorBufferTexture, 0);
	}
	glBindFramebuffer(GL_FRAMEBUFFER, 0);
	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
		std::cout << "COLOR_BUFFER Framebuffer not complete!" << std::endl;
	return colorBufferTexture;
}


unsigned int initSkybox()
{
	float vertices[] = {
		// back face
		-1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 0.0f, 0.0f, // bottom-left
		 1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 1.0f, 1.0f, // top-right
		 1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 1.0f, 0.0f, // bottom-right         
		 1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 1.0f, 1.0f, // top-right
		-1.0f, -1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 0.0f, 0.0f, // bottom-left
		-1.0f,  1.0f, -1.0f,  0.0f,  0.0f, -1.0f, 0.0f, 1.0f, // top-left
		// front face
		-1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f, 0.0f, // bottom-left
		 1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f, 0.0f, // bottom-right
		 1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f, 1.0f, // top-right
		 1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 1.0f, 1.0f, // top-right
		-1.0f,  1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f, 1.0f, // top-left
		-1.0f, -1.0f,  1.0f,  0.0f,  0.0f,  1.0f, 0.0f, 0.0f, // bottom-left
		// left face
		-1.0f,  1.0f,  1.0f, -1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-right
		-1.0f,  1.0f, -1.0f, -1.0f,  0.0f,  0.0f, 1.0f, 1.0f, // top-left
		-1.0f, -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-left
		-1.0f, -1.0f, -1.0f, -1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-left
		-1.0f, -1.0f,  1.0f, -1.0f,  0.0f,  0.0f, 0.0f, 0.0f, // bottom-right
		-1.0f,  1.0f,  1.0f, -1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-right
		// right face
		 1.0f,  1.0f,  1.0f,  1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-left
		 1.0f, -1.0f, -1.0f,  1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-right
		 1.0f,  1.0f, -1.0f,  1.0f,  0.0f,  0.0f, 1.0f, 1.0f, // top-right         
		 1.0f, -1.0f, -1.0f,  1.0f,  0.0f,  0.0f, 0.0f, 1.0f, // bottom-right
		 1.0f,  1.0f,  1.0f,  1.0f,  0.0f,  0.0f, 1.0f, 0.0f, // top-left
		 1.0f, -1.0f,  1.0f,  1.0f,  0.0f,  0.0f, 0.0f, 0.0f, // bottom-left     
		// bottom face
		-1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f, 0.0f, 1.0f, // top-right
		 1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f, 1.0f, 1.0f, // top-left
		 1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f, 1.0f, 0.0f, // bottom-left
		 1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f, 1.0f, 0.0f, // bottom-left
		-1.0f, -1.0f,  1.0f,  0.0f, -1.0f,  0.0f, 0.0f, 0.0f, // bottom-right
		-1.0f, -1.0f, -1.0f,  0.0f, -1.0f,  0.0f, 0.0f, 1.0f, // top-right
		// top face
		-1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f, 0.0f, 1.0f, // top-left
		 1.0f,  1.0f , 1.0f,  0.0f,  1.0f,  0.0f, 1.0f, 0.0f, // bottom-right
		 1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f, 1.0f, 1.0f, // top-right     
		 1.0f,  1.0f,  1.0f,  0.0f,  1.0f,  0.0f, 1.0f, 0.0f, // bottom-right
		-1.0f,  1.0f, -1.0f,  0.0f,  1.0f,  0.0f, 0.0f, 1.0f, // top-left
		-1.0f,  1.0f,  1.0f,  0.0f,  1.0f,  0.0f, 0.0f, 0.0f  // bottom-left        
	};
	unsigned int cubeVAO, cubeVBO;
	glGenVertexArrays(1, &cubeVAO);
	glGenBuffers(1, &cubeVBO);
	// fill buffer
	glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
	// link vertex attributes
	glBindVertexArray(cubeVAO);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(1);
	glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(3 * sizeof(float)));
	glEnableVertexAttribArray(2);
	glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
	glBindBuffer(GL_ARRAY_BUFFER, 0);
	glBindVertexArray(0);
	return cubeVAO;
}

void renderSkybox(unsigned int VAO) {
	glBindVertexArray(VAO);
	glDrawArrays(GL_TRIANGLES, 0, 36);
	glBindVertexArray(0);
}

void GLAPIENTRY
MessageCallback(GLenum source,
	GLenum type,
	GLuint id,
	GLenum severity,
	GLsizei length,
	const GLchar* message,
	const void* userParam)
{
	fprintf(stderr, "GL CALLBACK: %s type = 0x%x, severity = 0x%x, message = %s\n",
		(type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : ""),
		type, severity, message);
}