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#include "textrenderer.h"
#include "debug.h"
void TextRenderer::initialize(){
glGenVertexArrays(1, &m_vao);
glGenBuffers(1, &m_vbo);
glBindVertexArray(m_vao);
glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 6 * 4, NULL, GL_DYNAMIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 4 * sizeof(float), 0);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
void TextRenderer::renderUIText(std::shared_ptr<Font> font, std::string text, glm::vec2 anchorPosition, AnchorPoint anchorPoint, float textBoxWidth, float fontSize, float lineSpacing, glm::vec3 textColor){
glActiveTexture(GL_TEXTURE0);
glBindVertexArray(m_vao);
float x = 0;
float y = 0;
float maxY = font->getCharacter(73).size.y * fontSize;
float minY = - (font->getCharacter(106).size.y - font->getCharacter(106).bearing.y) * fontSize;
switch(anchorPoint){
case AnchorPoint::TopLeft:
x = anchorPosition.x;
y = anchorPosition.y - maxY;
break;
case AnchorPoint::TopCenter:
x = anchorPosition.x - textBoxWidth * 0.5f;
y = anchorPosition.y - maxY;
break;
case AnchorPoint::TopRight:
x = anchorPosition.x - textBoxWidth;
y = anchorPosition.y - maxY;
break;
}
float initX = x;
float initY = y;
std::string::const_iterator c;
for (c = text.begin(); c != text.end(); c++)
{
Character ch = font->getCharacter(*c);
float xpos = x + ch.bearing.x * fontSize;
float ypos = y - (ch.size.y - ch.bearing.y) * fontSize;
float w = ch.size.x * fontSize;
float h = ch.size.y * fontSize;
if(xpos + w > initX + textBoxWidth){
x = initX;
y -= (1.f + lineSpacing) * (maxY - minY);
xpos = x + ch.bearing.x * fontSize;
ypos = y - (ch.size.y - ch.bearing.y) * fontSize;
}
// update VBO for each character
float vertices[6][4] = {
{ xpos, ypos + h, 0.0f, 0.0f },
{ xpos, ypos, 0.0f, 1.0f },
{ xpos + w, ypos, 1.0f, 1.0f },
{ xpos, ypos + h, 0.0f, 0.0f },
{ xpos + w, ypos, 1.0f, 1.0f },
{ xpos + w, ypos + h, 1.0f, 0.0f }
};
// render glyph texture over quad
glBindTexture(GL_TEXTURE_2D, ch.textureID);
// update content of VBO memory
glBindBuffer(GL_ARRAY_BUFFER, m_vbo);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vertices), vertices);
glBindBuffer(GL_ARRAY_BUFFER, 0);
// render quad
glDrawArrays(GL_TRIANGLES, 0, 6);
// now advance cursors for next glyph (note that advance is number of 1/64 pixels)
x += (ch.advance >> 6) * fontSize; // bitshift by 6 to get value in pixels (2^6 = 64)
}
glBindVertexArray(0);
glBindTexture(GL_TEXTURE_2D, 0);
}
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