Partial Implement RenderText

src/JGL/JGL.cpp

@@ -1,10 +1,20 @@
 //
 // Created by dawsh on 1/17/24.
 //
+
+#include <glad/glad.h>
 #include <JGL/JGL.h>
 #include <GL/glut.h>
 #include "J3ML/LinearAlgebra/Transform2D.h"
 #include <rewindow/types/window.h>
+#include <freetype2/ft2build.h>
+#include FT_FREETYPE_H
+#include <iostream>
+
+
+GLuint program;
+GLuint texture;
+
 namespace JGL
 {
     Vector2 ScreenToViewport(const Vector2 &v) {
@@ -28,6 +38,80 @@ namespace JGL
         };
     }
 
+    FT_Face face;
+    FT_Library ft;
+
+    bool InitTextEngine() {
+        if (FT_Init_FreeType(&ft))
+        {
+            std::cout << "Error::FREETYPE: " << std::endl;
+            return false;
+        }
+
+        if (FT_New_Face(ft, "content/FreeSans.ttf", 0, &face))
+        {
+            std::cout << "Error::FREETYPE: Failed to load font!" << std::endl;
+            return false;
+        }
+        FT_Set_Pixel_Sizes(face, 0, 48);
+        return true;
+    }
+
+    void RenderText(std::string text, float x, float y, float scale) {
+        glUseProgram(0); // Fixed-function pipeline.
+        glColor3f(1.0f, 1.0f, 1.0f);
+
+        const char* c;
+        for (c = text.c_str(); *c; c++)
+        {
+            if (FT_Load_Char(face, *c, FT_LOAD_RENDER))
+                continue;
+
+            FT_GlyphSlot g = face->glyph;
+
+            glActiveTexture(GL_TEXTURE0);
+            glBindTexture(GL_TEXTURE_2D, texture);
+            glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, g->bitmap.width, g->bitmap.rows, 0, GL_RED, GL_UNSIGNED_BYTE, g->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);
+
+            float x2 = x + g->bitmap_left * scale;
+            float y2 = -y - g->bitmap_top * scale; // Adjust y-coordinate
+            float w = g->bitmap.width * scale;
+            float h = g->bitmap.rows * scale;
+
+            glBegin(GL_TRIANGLES);
+
+            glTexCoord2f(0, 0);
+            glVertex2f(x2, y2);
+
+            glTexCoord2f(0, 1);
+            glVertex2f(x2, y2 + h);
+
+            glTexCoord2f(1, 1);
+            glVertex2f(x2 + w, y2 + h);
+
+            glTexCoord2f(0, 0);
+            glVertex2f(x2, y2);
+
+            glTexCoord2f(1, 1);
+            glVertex2f(x2 + w, y2 + h);
+
+            glTexCoord2f(1, 0);
+            glVertex2f(x2 + w, y2);
+
+            glEnd();
+
+            x += (g->advance.x >> 6) * scale;
+            y += (g->advance.y >> 6) * scale;
+
+        }
+
+        glBindTexture(GL_TEXTURE_2D, 0); // Unbind texture
+    }
+
     namespace J2D
     {
         void FillRect2D(const Color3 &color, const Vector2 &pos, const Vector2 &size) {