First iteration with font/text support

6 files changed, 323 insertions, 1 deletions

diff --git a/ui/font.cpp b/ui/font.cpp
new file mode 100644
index 0000000..5596f20
--- /dev/null
+++ b/ui/font.cpp
@@ -0,0 +1,182 @@
+#include "font.h"
+#include <algorithm>
+#include <cctype>
+#include <ft2build.h>
+#include FT_FREETYPE_H
+#include <glRef.hpp>
+#include <maths.h>
+#include <memory>
+#include <optional>
+#include <stdexcept>
+#include <unicode.h>
+#include <utility>
+// IWYU pragma: no_forward_declare FT_LibraryRec_
+
+std::string
+FT_Error_StringSafe(FT_Error err)
+{
+	if (const auto errstr = FT_Error_String(err)) {
+		return {errstr};
+	}
+	return std::to_string(err);
+}
+
+template<auto Func, typename... Args>
+void
+FT_Check(Args &&... args)
+{
+	if (const auto err = Func(std::forward<Args>(args)...)) {
+		throw std::runtime_error {std::string {"FreeType error: "} + FT_Error_StringSafe(err)};
+	}
+}
+
+const std::string BASIC_CHARS = []() {
+	std::string chars;
+	for (char c {}; c >= 0; c++) {
+		if (isgraph(c)) {
+			chars += c;
+		}
+	}
+	return chars + "£€²³";
+}();
+
+using FT = glRef<FT_Library,
+		[]() {
+			FT_Library ft {};
+			FT_Check<FT_Init_FreeType>(&ft);
+			return ft;
+		},
+		FT_Done_FreeType>;
+
+using Face = glRef<FT_Face,
+		[](FT_Library ft, const char * const name) {
+			FT_Face face {};
+			FT_Check<FT_New_Face>(ft, name, 0, &face);
+			return face;
+		},
+		FT_Done_Face>;
+
+Font::Font(const char * const p, unsigned s) : path {p}, size {getTextureSize(s)}
+{
+	generateChars(BASIC_CHARS);
+}
+
+void
+Font::generateChars(const std::string_view chars) const
+{
+	std::optional<FT> ft;
+	std::optional<Face> face;
+
+	for (auto c = chars.data(); c <= &chars.back(); c = next_char(c)) {
+		const auto codepoint = get_codepoint(c);
+		if (charsData.find(codepoint) == charsData.end()) {
+			if (!ft) {
+				ft.emplace();
+			}
+			if (!face) {
+				face.emplace(*ft, path.c_str());
+				FT_Set_Pixel_Sizes(*face, 0, size.z);
+			}
+			FT_UInt glyph_index = FT_Get_Char_Index(*face, codepoint);
+			if (FT_Load_Glyph(*face, glyph_index, FT_LOAD_RENDER)) {
+				charsData.emplace(codepoint, CharData {});
+				continue;
+			}
+
+			const auto & glyph = (*face)->glyph;
+			const auto textureIdx = getTextureWithSpace(glyph->bitmap.width);
+			auto & texture = fontTextures[textureIdx];
+
+			glTexSubImage2D(GL_TEXTURE_2D, 0, static_cast<GLint>(texture.used), 0,
+					static_cast<GLsizei>(glyph->bitmap.width), static_cast<GLsizei>(glyph->bitmap.rows), GL_RED,
+					GL_UNSIGNED_BYTE, glyph->bitmap.buffer);
+
+			const auto & cd = charsData
+									  .emplace(codepoint,
+											  CharData {textureIdx, {glyph->bitmap.width, glyph->bitmap.rows},
+													  {texture.used, 0}, {glyph->bitmap_left, glyph->bitmap_top},
+													  glyph->advance.x >> 6})
+									  .first->second;
+			texture.used += cd.size.x;
+		}
+	}
+}
+
+std::size_t
+Font::getTextureWithSpace(unsigned int adv) const
+{
+	if (auto itr = std::find_if(fontTextures.begin(), fontTextures.end(),
+				[adv, this](const FontTexture & ft) {
+					return (ft.used + adv) < size.x;
+				});
+			itr != fontTextures.end()) {
+		glBindTexture(GL_TEXTURE_2D, itr->texture);
+		return static_cast<std::size_t>(itr - fontTextures.begin());
+	}
+
+	auto & texture = fontTextures.emplace_back();
+	glGenTextures(1, &texture.texture);
+	glBindTexture(GL_TEXTURE_2D, texture.texture);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, static_cast<GLsizei>(size.x), static_cast<GLsizei>(size.y), 0, GL_RED,
+			GL_UNSIGNED_BYTE, nullptr);
+	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);
+
+	return fontTextures.size() - 1;
+}
+
+glm::uvec3
+Font::getTextureSize(unsigned int height)
+{
+	auto pow2 = [](unsigned int target) {
+		unsigned int v {8};
+		do {
+			v <<= 1;
+		} while (v << 1 < GL_MAX_TEXTURE_SIZE && v < target);
+		return v;
+	};
+
+	constexpr const unsigned int WIDTH_PER_HEIGHT {64};
+	return {pow2(height * WIDTH_PER_HEIGHT), pow2(height), height};
+}
+
+Font::TextureQuads
+Font::render(const std::string_view chars) const
+{
+	constexpr static const std::array<std::pair<glm::vec2, glm::vec2>, 4> C {{
+			{{0, 0}, {0, 1}},
+			{{1, 0}, {1, 1}},
+			{{1, 1}, {1, 0}},
+			{{0, 1}, {0, 0}},
+	}};
+
+	generateChars(chars);
+
+	glm::vec2 pos {};
+	TextureQuads out;
+	for (auto c = chars.data(); c <= &chars.back(); c = next_char(c)) {
+		if (isspace(*c)) {
+			pos.x += static_cast<float>(size.y) / 4.F;
+			continue;
+		}
+		const auto & ch = charsData.at(get_codepoint(c));
+		if (!ch.advance) {
+			continue;
+		}
+
+		const auto charPos = pos + glm::vec2 {ch.bearing.x, ch.bearing.y - static_cast<int>(ch.size.y)};
+		const auto size = glm::vec2 {ch.size};
+
+		Quad q;
+		std::transform(C.begin(), C.end(), q.begin(), [&size, &charPos, &ch, this](const auto & c) {
+			return (charPos + (size * c.first))
+					|| ((glm::vec2 {ch.position} + (glm::vec2 {ch.size} * c.second)) / glm::vec2 {this->size});
+		});
+		out[fontTextures[ch.textureIdx].texture].emplace_back(q);
+
+		pos.x += static_cast<float>(ch.advance);
+	}
+	return out;
+}
diff --git a/ui/font.h b/ui/font.h
new file mode 100644
index 0000000..c9d834a
--- /dev/null
+++ b/ui/font.h
@@ -0,0 +1,48 @@
+#ifndef FONT_H
+#define FONT_H
+
+#include <GL/glew.h>
+#include <array>
+#include <cstddef>
+#include <cstdint>
+#include <glm/glm.hpp>
+#include <map>
+#include <string>
+#include <string_view>
+#include <vector>
+
+class Font {
+public:
+	Font(const char * const path, unsigned int height);
+
+	using Quad = std::array<glm::vec4, 4>;
+	using Quads = std::vector<Quad>;
+	using TextureQuads = std::map<GLuint /*textureId*/, Quads>;
+	TextureQuads render(const std::string_view text) const;
+
+	struct CharData {
+		size_t textureIdx;
+		glm::uvec2 size;
+		glm::uvec2 position;
+		glm::ivec2 bearing;
+		long advance;
+	};
+	struct FontTexture {
+		GLuint texture;
+		unsigned int used;
+	};
+
+	static glm::uvec3 getTextureSize(unsigned int height);
+
+protected:
+	void generateChars(const std::string_view text) const;
+	const CharData getChar(char) const;
+	std::size_t getTextureWithSpace(unsigned int adv) const;
+
+	std::string path;
+	glm::uvec3 size;
+	mutable std::map<uint32_t, CharData> charsData;
+	mutable std::vector<FontTexture> fontTextures;
+};
+
+#endif
diff --git a/ui/text.cpp b/ui/text.cpp
new file mode 100644
index 0000000..be696c3
--- /dev/null
+++ b/ui/text.cpp
@@ -0,0 +1,59 @@
+#include "text.h"
+#include "font.h"
+#include "gfx/gl/uiShader.h"
+#include "uiComponent.h"
+#include <array>
+#include <glBuffers.h>
+#include <glVertexArrays.h>
+#include <glm/gtc/type_ptr.hpp>
+#include <map>
+#include <utility>
+
+const auto font {"/usr/share/fonts/hack/Hack-Regular.ttf"};
+Text::Text(std::string_view s, Position pos, glm::vec3 c) : UIComponent {pos}, colour {c}
+{
+	for (const auto & textureQuads : Font {font, static_cast<unsigned int>(pos.size.y)}.render(s)) {
+		auto & rendering
+				= models.emplace_back(textureQuads.first, static_cast<GLsizei>(6 * textureQuads.second.size()));
+		glBindVertexArray(rendering.vao);
+
+		glBindBuffer(GL_ARRAY_BUFFER, rendering.vbo);
+		std::vector<glm::vec4> vertices;
+		vertices.reserve(6 * textureQuads.second.size());
+		for (const auto & quad : textureQuads.second) {
+			for (auto offset = 0U; offset < 3; offset += 2) {
+				for (auto vertex = 0U; vertex < 3; vertex += 1) {
+					vertices.emplace_back(quad[(vertex + offset) % 4] + glm::vec4 {position.origin, 0, 0});
+				}
+			}
+		};
+		glBufferData(GL_ARRAY_BUFFER, static_cast<GLsizeiptr>(sizeof(glm::vec4)) * rendering.count,
+				glm::value_ptr(vertices.front()), GL_STATIC_DRAW);
+
+		glEnableVertexAttribArray(0);
+		glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, sizeof(glm::vec4), nullptr);
+
+		glBindVertexArray(0);
+	}
+}
+
+void
+Text::render(const UIShader & shader, const Position &) const
+{
+	shader.useText(colour);
+	for (const auto & m : models) {
+		glBindTexture(GL_TEXTURE_2D, m.texture);
+		glBindVertexArray(m.vao);
+		glDrawArrays(GL_TRIANGLES, 0, m.count);
+	}
+	glBindVertexArray(0);
+	glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+bool
+Text::handleInput(const SDL_Event &, const Position &)
+{
+	return false;
+}
+
+Text::Model::Model(GLuint t, GLsizei c) : texture {t}, count {c} { }
diff --git a/ui/text.h b/ui/text.h
new file mode 100644
index 0000000..81122de
--- /dev/null
+++ b/ui/text.h
@@ -0,0 +1,31 @@
+#pragma once
+
+#include "uiComponent.h"
+#include <GL/glew.h>
+#include <glBuffers.h>
+#include <glVertexArrays.h>
+#include <glm/glm.hpp>
+#include <string_view>
+#include <vector>
+
+class UIShader;
+union SDL_Event;
+
+class Text : public UIComponent {
+public:
+	Text(std::string_view s, Position, glm::vec3 colour);
+
+	void render(const UIShader &, const Position & parentPos) const override;
+	bool handleInput(const SDL_Event &, const Position & parentPos) override;
+
+private:
+	struct Model {
+		Model(GLuint, GLsizei);
+		GLuint texture;
+		GLsizei count;
+		glVertexArray vao;
+		glBuffer vbo;
+	};
+	std::vector<Model> models;
+	glm::vec3 colour;
+};
diff --git a/ui/toolbar.cpp b/ui/toolbar.cpp
index c8febce..ada97b0 100644
--- a/ui/toolbar.cpp
+++ b/ui/toolbar.cpp
@@ -1,4 +1,5 @@
 #include "toolbar.h"
+#include "gfx/gl/uiShader.h"
 #include "ui/iconButton.h"
 #include "ui/uiComponent.h"
 #include "uiComponentPlacer.h"
@@ -17,6 +18,7 @@ Toolbar::Toolbar(const std::initializer_list<InitInfo> & initInfo) : UIComponent
 void
 Toolbar::render(const UIShader & uiShader, const Position & parentPos) const
 {
+	uiShader.useDefault();
 	const auto absPos = this->position + parentPos;
 	icons.apply(&UIComponent::render, uiShader, absPos);
 }
diff --git a/ui/window.cpp b/ui/window.cpp
index 13c7d95..6a263aa 100644
--- a/ui/window.cpp
+++ b/ui/window.cpp
@@ -13,6 +13,7 @@ SDL_GL_CreateContextAndGlewInit(SDL_Window * w)
 	if (glewInit() != GLEW_OK) {

 		throw std::runtime_error {"Glew failed to initialize!"};

 	}

+	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

 	glEnable(GL_CULL_FACE);

 	glCullFace(GL_BACK);

 	glEnable(GL_BLEND);

@@ -89,7 +90,6 @@ Window::refresh(const GameState * gameState) const
 void

 Window::render(const GameState *) const

 {

-	uiShader.use();

 	glDisable(GL_DEPTH_TEST);

 	uiComponents.apply(&UIComponent::render, uiShader, UIComponent::Position {});

 }