源码下载及编译

点击此链接进入下载地址
https://download.savannah.gnu.org/releases/freetype/

下载完毕后在windows下找到freetype.sln进行编译(如下图位置)

编译生成的dll及lib

（本项目使用vs2017进行编译）,编译文件生成地址在objs里

使用FreeType

include头文件加载

附加包含目录

注意把freetype的头文件复制到根目录，而不是 放到 "include/freeType"文件夹内部（编译会报错）

lib文件加载

添加lib文件位置

添加lib文件下的lib名

字体使用

选择 C:\Windows\Fonts下的字体文件即可（或网上下载）

代码编写

代码初始化

#include <ft2build.h>
#include FT_FREETYPE_H  

FT_Library ft,ft1;
if (FT_Init_FreeType(&ft)) std::cout << "ERROR::FREETYPE: Could not init FreeType Library" << std::endl;
if (FT_Init_FreeType(&ft1)) std::cout << "ERROR::FREETYPE: Could not init FreeType Library" << std::endl;

if (FT_New_Face(ft, "Fonts/simsun.ttc", 0, &face)) std::cout << "ERROR::FREETYPE: Failed to load font" << std::endl;
if (FT_New_Face(ft1, "Fonts/simsun.ttc", 0, &face1)) std::cout << "ERROR::FREETYPE: Failed to load font" << std::endl;

中文字体输出简单封装

完整代码 learnOpenGL-CN

void RenderText_CN(Shader &shader, std::wstring text, GLfloat x, GLfloat y, GLfloat scale, glm::vec3 color, GLuint VAO, GLuint VBO, FT_Face face, FT_Library ft)
{
	shader.use();
	glUniform3f(glGetUniformLocation(shader.ID, "textColor"), color.x, color.y, color.z);
	glActiveTexture(GL_TEXTURE0);
	glBindVertexArray(VAO);

	for (auto c : text)
	{
		//if (Characters.find(c) == Characters.end()||1)
		//{
			if (FT_Load_Char(face, c, FT_LOAD_RENDER))
			{
				std::cerr << "ERROR::FREETYPE: Failed to load Glyph" << std::endl;
				continue;
			}
			GLuint texture;
			glGenTextures(1, &texture);
			glBindTexture(GL_TEXTURE_2D, texture);
			glTexImage2D(
				GL_TEXTURE_2D,
				0,
				GL_RED,
				face->glyph->bitmap.width,
				face->glyph->bitmap.rows,
				0,
				GL_RED,
				GL_UNSIGNED_BYTE,
				face->glyph->bitmap.buffer
			);
			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);

			Character character = {
				texture,
				glm::ivec2(face->glyph->bitmap.width, face->glyph->bitmap.rows),
				glm::ivec2(face->glyph->bitmap_left, face->glyph->bitmap_top),
				face->glyph->advance.x
			};
			//Characters[c] = character;
		//}

			Character ch = character;// Characters[c];

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

		x += (ch.Advance >> 6) * scale;
		glDeleteTextures(1, &texture);//openGL gen的必须delete不然会导致软件内存越来越大
	}

	glBindVertexArray(0);
	glBindTexture(GL_TEXTURE_2D, 0);
}

存在问题列表

问题1：无法打开stddef.h

vs2017（win10版本）:
“项目”-“配置属性”-“常规”-"windows SDK版本"选择10.0.17763.0

其他问题后续更新