1 files changed, 131 insertions, 0 deletions
diff --git a/src/font.cpp b/src/font.cpp
new file mode 100644
index 0000000..adffa9c
--- /dev/null
+++ b/src/font.cpp
@@ -0,0 +1,131 @@
+#include <font.hpp>
+
+FT_Library FontSystem::ftLibrary;
+FT_Face FontSystem::ftFace;
+
+std::string FontSystem::fontFamily;
+std::map<int, std::vector<FT_Info>> FontSystem::fontData;
+
+int FontSystem::currentSize = 0;
+Color FontSystem::currentColor;
+float FontSystem::currentZ = -8.0f;
+
+void FontSystem::init(const std::string& ttf)
+{
+	FT_Init_FreeType(&ftLibrary);
+	FT_New_Face(ftLibrary, ttf.c_str(), 0, &ftFace);
+}
+
+void FontSystem::setFontSize(int size)
+{
+	auto result = fontData.try_emplace(size, 93);
+	if (result.second) {
+		FT_Set_Pixel_Sizes(ftFace, 0, size);
+
+		char c = 33;
+		for (auto& d : fontData.at(size)) {
+			glDeleteTextures(1, &d.tex);
+			glGenTextures(1, &d.tex);    //	Generate new texture name/locations?
+
+			// load the character from the font family file
+			FT_Load_Char(ftFace, c++, FT_LOAD_RENDER);
+
+			// transfer the character's bitmap (?) to a texture for rendering
+			glBindTexture(GL_TEXTURE_2D, d.tex);
+			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S , GL_CLAMP_TO_EDGE);
+			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T , GL_CLAMP_TO_EDGE);
+			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER , GL_LINEAR);
+			glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER , GL_LINEAR);
+			glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+
+			/**
+			 * The just-created texture will render red-on-black if we don't do anything to it, so
+			 * here we create a buffer 4 times the size and transform the texture into an RGBA array,
+			 * making it white-on-black.
+			 */
+			auto& g = ftFace->glyph;
+			std::vector<uint32_t> buf (g->bitmap.width * g->bitmap.rows, 0xFFFFFFFF);
+			for (auto j = buf.size(); j--;)
+				buf[j] ^= !g->bitmap.buffer[j] ? buf[j] : 0;
+
+			d.wh.x = g->bitmap.width;
+			d.wh.y = g->bitmap.rows;
+			d.bl.x = g->bitmap_left;
+			d.bl.y = g->bitmap_top;
+			d.ad.x = g->advance.x >> 6;
+			d.ad.y = g->advance.y >> 6;
+			glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, g->bitmap.width, g->bitmap.rows,
+				0, GL_RGBA, GL_UNSIGNED_BYTE, buf.data());
+		}
+	}
+
+	currentSize = size;
+}
+
+void FontSystem::setFontColor(float r, float g, float b)
+{
+	currentColor.red = r;
+	currentColor.green = g;
+	currentColor.blue = b;
+}
+
+void FontSystem::setFontZ(float z)
+{
+	currentZ = z;
+}
+
+vec2 FontSystem::putChar(float xx, float yy, char c)
+{
+	const auto& ch = fontData.at(currentSize)[c - 33];
+	int x = xx, y = yy;
+
+	// get dimensions of the rendered character
+	vec2 c1 = {
+		static_cast<float>(floor(x) + ch.bl.x),
+		static_cast<float>(floor(y) + ch.bl.y)
+	};
+	const auto& c2 = ch.wh;
+
+	Render::textShader.use();
+	Render::textShader.enable();
+
+	// draw the character
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, ch.tex);
+
+	glUniform4f(Render::textShader.uniform[WU_tex_color], 1.0f, 1.0f, 1.0f, 1.0f);
+
+	GLfloat tex_coord[] = {
+		0.0, 1.0, // bottom left
+		1.0, 1.0, // bottom right
+		1.0, 0.0, // top right
+		1.0, 0.0, // top right
+		0.0, 0.0, // top left
+		0.0, 1.0, // bottom left
+	};
+
+	GLfloat text_vert[] = {
+		c1.x,        c1.y - c2.y, currentZ,        // bottom left
+		c1.x + c2.x, c1.y - c2.y, currentZ,        // bottom right
+		c1.x + c2.x, c1.y + c2.y - c2.y, currentZ, // top right
+		c1.x + c2.x, c1.y + c2.y - c2.y, currentZ, // top right
+		c1.x,        c1.y + c2.y - c2.y, currentZ, // top left
+		c1.x,        c1.y - c2.y, currentZ         // bottom left
+	};
+
+	glUniform4f(Render::textShader.uniform[WU_tex_color],
+		currentColor.red, currentColor.green, currentColor.blue, currentColor.alpha);
+
+	glVertexAttribPointer(Render::textShader.coord, 3, GL_FLOAT, GL_FALSE, 0, text_vert);
+	glVertexAttribPointer(Render::textShader.tex, 2, GL_FLOAT, GL_FALSE, 0, tex_coord);
+	glDrawArrays(GL_TRIANGLES, 0, 6);
+
+	glUniform4f(Render::textShader.uniform[WU_tex_color], 1.0, 1.0, 1.0, 1.0); 
+
+	Render::textShader.disable();
+	Render::textShader.unuse();
+
+	// return the width.
+	return ch.ad;
+}
+