axyz/src/Engine/Rendering/TextPass.cpp

#include "Rendering/TextPass.h"

TextPass::TextPass()
{

}

void TextPass::Initialize()
{
	glGenVertexArrays(1, &VAO);
	glGenBuffers(1, &VBO);
	glBindVertexArray(VAO);
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 6 * 4, NULL, GL_DYNAMIC_DRAW);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 4 * sizeof(GLfloat), 0);
	glBindBuffer(GL_ARRAY_BUFFER, 0);
	glBindVertexArray(0);

	m_TextProgram = ResourceManager::Load<ShaderProgram>("#TextProgram");
	m_TextProgram->AddShader(std::shared_ptr<Shader>(new VertexShader("Shaders/Text.vert.glsl")));
	m_TextProgram->AddShader(std::shared_ptr<Shader>(new FragmentShader("Shaders/Text.frag.glsl")));
	m_TextProgram->Compile();
	m_TextProgram->BindFragDataLocation(0, "sceneColor");
	m_TextProgram->BindFragDataLocation(1, "bloomColor");
	m_TextProgram->Link();
}

void TextPass::Update()
{

}

void TextPass::Draw(RenderScene& scene, FrameBuffer& frameBuffer)
{
	GLERROR("Derp1");
	TextPassState* state = new TextPassState(frameBuffer.GetHandle());
	for (auto &job : scene.Jobs.Text) {
		auto textJob = std::dynamic_pointer_cast<TextJob>(job);
		if (textJob) {

			renderText(textJob->Content, textJob->Resource, textJob->Alignment, textJob->Color, textJob->Matrix, scene.Camera->ProjectionMatrix(), scene.Camera->ViewMatrix());
		}
	}
	GLERROR("Derp2");
	delete state;
}

std::string TextPass::parseColors(std::string text, std::map<int, glm::vec4>& colorChanges, glm::vec4 originalColor)
{
	std::string parsedString = text;
	glm::vec4 newColor = originalColor;
	bool colorChange = false;

	for (std::string::const_iterator c = parsedString.begin(); c != parsedString.end(); c++) {
		if (*c == char(92)) { // Backlash
			if ((c + 1) != parsedString.end()) {
				if (*(c + 1) == char('C')) { // C for Color 
					if ((c + 7) != parsedString.end()) {
						bool hasCorrectFormat = true;

						for (std::string::const_iterator colorC = c + 2; colorC != c + 8; colorC++) {
							if (*colorC < '0' || *colorC > 'F') {
								hasCorrectFormat = false;
								break;
							}
						}

						if (hasCorrectFormat == true) {
							colorChange = true;

							std::array<int, 3> hexToInt = {
								std::stoi(std::string(c + 2, c + 4), 0, 16),
								std::stoi(std::string(c + 4, c + 6), 0, 16),
								std::stoi(std::string(c + 6, c + 8), 0, 16)
							};

							newColor = glm::vec4(
								float(hexToInt[0]) / 255.f,
								float(hexToInt[1]) / 255.f,
								float(hexToInt[2]) / 255.f,
								newColor.a);

							parsedString.erase(c, (c + 8));
						}
					}
				}

				if (*(c + 1) == char('A')) { // A for Alpha
					if ((c + 3) != parsedString.end()) {
						bool hasCorrectFormat = true;

						for (std::string::const_iterator colorC = c + 2; colorC != c + 4; colorC++) {
							if (*colorC < '0' || *colorC > 'F') {
								hasCorrectFormat = false;
								break;
							}
						}

						if (hasCorrectFormat == true) {
							colorChange = true;

							int hexToInt = std::stoi(std::string(c + 2, c + 4), 0, 16);

							newColor = glm::vec4(
								newColor.r,
								newColor.g,
								newColor.b,
								float(hexToInt) / 255.f);

							parsedString.erase(c, (c + 4));
						}
					}
				}

				if ((*(c + 1) >= '1' && *(c + 1) <= '9') || *(c + 1) == 'B' || *(c + 1) == 'E' || *(c + 1) == 'F') { // Icons
					if (*(c + 1) >= '1' && *(c + 1) <= '9') {
						parsedString.replace(c, (c + 2), 1, (*(c + 1) - 48));
					}
					else {
						parsedString.replace(c, (c + 2), 1, (*(c + 1) - 55));
					}
				}

				if (colorChange) {
					colorChanges[c - parsedString.begin()] = newColor;
				}
			}
		}
	}



	return parsedString;
}

void TextPass::renderText(std::string text, Font* font, TextJob::AlignmentEnum alignment, glm::vec4 color, glm::mat4 modelMatrix, glm::mat4 projectionMatrix, glm::mat4 viewMatrix)
{
	GLfloat penX = 0;
	GLfloat penY = 0;
	GLfloat scale = 1.0 / font->FontSize;

	GLfloat stringWidth = 0.f;

	std::map<int, glm::vec4> colorChanges;
	std::string parsedText = parseColors(text, colorChanges, color);

	for (std::string::const_iterator c = parsedText.begin(); c != parsedText.end(); c++) {
		Font::Character ch = font->m_Characters[*c];
		stringWidth += (ch.Advance >> 6) * scale;
	}

	if (alignment == TextJob::AlignmentEnum::Center) {
		penX = -stringWidth / 2.f;
	}
	else if (alignment == TextJob::AlignmentEnum::Right) {
		penX = -stringWidth;
	}
	else {
		penX = 0;
	}



	m_TextProgram->Bind();
	glUniform4fv(glGetUniformLocation(m_TextProgram->GetHandle(), "textColor"), 1, glm::value_ptr(color));
	glUniformMatrix4fv(glGetUniformLocation(m_TextProgram->GetHandle(), "M"), 1, GL_FALSE, glm::value_ptr(modelMatrix));
	glUniformMatrix4fv(glGetUniformLocation(m_TextProgram->GetHandle(), "V"), 1, GL_FALSE, glm::value_ptr(viewMatrix));
	glUniformMatrix4fv(glGetUniformLocation(m_TextProgram->GetHandle(), "P"), 1, GL_FALSE, glm::value_ptr(projectionMatrix));
	glActiveTexture(GL_TEXTURE0);
	glBindVertexArray(VAO);


	for (std::string::const_iterator c = parsedText.begin(); c != parsedText.end(); c++) {

		auto it = colorChanges.find(c - parsedText.begin());
		if (it != colorChanges.end()) {
			glUniform4fv(glGetUniformLocation(m_TextProgram->GetHandle(), "textColor"), 1, glm::value_ptr(it->second));
		}

		Font::Character ch = font->m_Characters[*c];

		GLfloat xpos = penX + ch.Bearing.x * scale;
		GLfloat ypos = penY - (ch.Size.y - ch.Bearing.y) * scale;

		GLfloat w = ch.Size.x * scale;
		GLfloat h = ch.Size.y * scale;

		GLfloat vertices[6][4] = {
			{ xpos, ypos + h, 0.0, 0.0 },
			{ xpos, ypos, 0.0, 1.0 },
			{ xpos + w, ypos, 1.0, 1.0 },

			{ xpos, ypos + h, 0.0, 0.0 },
			{ xpos + w, ypos, 1.0, 1.0 },
			{ xpos + w, ypos + h, 1.0, 0.0 }
		};

		glBindTexture(GL_TEXTURE_2D, ch.TextureID);

		glBindBuffer(GL_ARRAY_BUFFER, VBO);
		glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
		glBindBuffer(GL_ARRAY_BUFFER, 0);
		glDrawArrays(GL_TRIANGLES, 0, 6);
		penX += (ch.Advance >> 6) * scale; // Bitshift by 6 to get value in pixels (2^6 = 64)
	}
	glBindVertexArray(0);
	glBindTexture(GL_TEXTURE_2D, 0);

	GLERROR("Text rendering Error");
}