From 1f68fe78e84f25c8ddacdc37a293a5de31725bab Mon Sep 17 00:00:00 2001
From: Dan Goodliffe <dan@randomdan.homeip.net>
Date: Sat, 1 Jan 2022 13:01:08 +0000
Subject: First iteration with font/text support

---
 ui/text.cpp | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 ui/text.cpp

(limited to 'ui/text.cpp')

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} { }
-- 
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