Aegisub/aegisub/src/gl_text.cpp

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// Copyright (c) 2007, Rodrigo Braz Monteiro
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of the Aegisub Group nor the names of its contributors
// may be used to endorse or promote products derived from this software
// without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Aegisub Project http://www.aegisub.org/
/// @file gl_text.cpp
/// @brief Create and render text using OpenGL
/// @ingroup video_output
///
#include "config.h"
#include "gl_text.h"
#include "compat.h"
#include "utils.h"
#include <libaegisub/color.h>
#include <wx/bitmap.h>
#include <wx/dcmemory.h>
#include <algorithm>
#include <boost/noncopyable.hpp>
#ifdef HAVE_OPENGL_GL_H
#include <OpenGL/gl.h>
#else
#include <GL/gl.h>
#endif
namespace {
/// @class OpenGLTextGlyph
/// @brief Struct storing the information needed to draw a glyph
struct OpenGLTextGlyph {
wxString str; ///< String containing the glyph(s) this is for
int tex; ///< OpenGL texture to draw for this glyph
float x1; ///< Left x coordinate of this glyph in the containing texture
float x2; ///< Right x coordinate of this glyph in the containing texture
float y1; ///< Left y coordinate of this glyph in the containing texture
float y2; ///< Right y coordinate of this glyph in the containing texture
int w; ///< Width of the glyph in pixels
int h; ///< Height of the glyph in pixels
wxFont font; ///< Font used for this glyph
OpenGLTextGlyph(int value, wxFont const& font)
: str(wxChar(value))
, tex(0)
, x1(0)
, x2(0)
, y1(0)
, y2(0)
, font(font)
{
wxCoord desc,lead;
wxBitmap tempBmp(32, 32, 24);
wxMemoryDC dc(tempBmp);
dc.SetFont(font);
dc.GetTextExtent(str, &w, &h, &desc, &lead);
}
void Draw(float x, float y) const {
glBindTexture(GL_TEXTURE_2D, tex);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
float tex_coords[] = {
x1, y1,
x1, y2,
x2, y2,
x2, y1
};
float vert_coords[] = {
x, y,
x, y + h,
x + w, y + h,
x + w, y
};
glVertexPointer(2, GL_FLOAT, 0, vert_coords);
glTexCoordPointer(2, GL_FLOAT, 0, tex_coords);
glDrawArrays(GL_QUADS, 0, 4);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
};
/// @class OpenGLTextTexture
/// @brief OpenGL texture which stores one or more glyphs as sprites
class OpenGLTextTexture : boost::noncopyable {
int x; ///< Next x coordinate at which a glyph can be inserted
int y; ///< Next y coordinate at which a glyph can be inserted
int nextY; ///< Y coordinate of the next line; tracked due to that lines
///< are only as tall as needed to fit the glyphs in them
int width; ///< Width of the texture
int height; ///< Height of the texture
GLuint tex; ///< The texture
/// Insert the glyph into this texture at the current coordinates
void Insert(OpenGLTextGlyph &glyph) {
int w = glyph.w;
int h = glyph.h;
// Fill glyph structure
glyph.x1 = float(x)/width;
glyph.y1 = float(y)/height;
glyph.x2 = float(x+w)/width;
glyph.y2 = float(y+h)/height;
glyph.tex = tex;
// Create bitmap and bind it to a DC
wxBitmap bmp(w + (w & 1), h + (h & 1), 24);
wxMemoryDC dc(bmp);
// Draw text and convert to image
dc.SetBackground(*wxBLACK_BRUSH);
dc.Clear();
dc.SetFont(glyph.font);
dc.SetTextForeground(*wxWHITE);
dc.DrawText(glyph.str, 0, 0);
// Convert RGB24 to Luminance + Alpha by using an arbitrary channel as A
wxImage img = bmp.ConvertToImage();
int imgw = img.GetWidth();
int imgh = img.GetHeight();
std::vector<unsigned char> alpha(imgw * imgh * 2, 255);
const unsigned char *read = img.GetData();
for (size_t write = 1; write < alpha.size(); write += 2, read += 3)
alpha[write] = *read;
// Upload image to video memory
glBindTexture(GL_TEXTURE_2D, tex);
glTexSubImage2D(GL_TEXTURE_2D, 0, x, y, imgw, imgh, GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE, &alpha[0]);
if (glGetError()) throw "Internal OpenGL text renderer error: Error uploading glyph data to video memory.";
}
public:
OpenGLTextTexture(OpenGLTextGlyph &glyph)
: x(0)
, y(0)
, nextY(0)
, width(std::max(SmallestPowerOf2(glyph.w), 64))
, height(std::max(SmallestPowerOf2(glyph.h), 64))
, tex(0)
{
width = height = std::max(width, height);
// Generate and bind
glGenTextures(1, &tex);
glBindTexture(GL_TEXTURE_2D, tex);
// Texture parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
// Allocate texture
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, nullptr);
if (glGetError()) throw "Internal OpenGL text renderer error: Could not allocate Text Texture";
TryToInsert(glyph);
}
OpenGLTextTexture(OpenGLTextTexture&& rhs)
: x(rhs.x)
, y(rhs.y)
, nextY(rhs.nextY)
, width(rhs.width)
, height(rhs.height)
, tex(rhs.tex)
{
rhs.tex = 0;
}
~OpenGLTextTexture() {
if (tex) glDeleteTextures(1, &tex);
}
/// @brief Try to insert a glyph into this texture
/// @param[in][out] glyph Texture to insert
/// @return Was the texture successfully added?
bool TryToInsert(OpenGLTextGlyph &glyph) {
if (glyph.w > width) return false;
if (y + glyph.h > height) return false;
// Can fit in this row?
if (x + glyph.w < width) {
Insert(glyph);
x += glyph.w;
nextY = std::max(nextY, y + glyph.h);
return true;
}
// Can fit the next row?
if (nextY + glyph.h > height) return false;
x = 0;
y = nextY;
return TryToInsert(glyph);
}
};
}
OpenGLText::OpenGLText()
: r(1.f)
, g(1.f)
, b(1.f)
, a(1.f)
, fontSize(0)
, fontBold(false)
, fontItalics(false)
{
}
OpenGLText::~OpenGLText() {
}
void OpenGLText::SetFont(std::string const& face, int size, bool bold, bool italics) {
// No change required
if (size == fontSize && face == fontFace && bold == fontBold && italics == fontItalics) return;
// Set font
fontFace = face;
fontSize = size;
fontBold = bold;
fontItalics = italics;
font.SetFaceName(to_wx(fontFace));
font.SetPointSize(size);
font.SetWeight(bold ? wxFONTWEIGHT_BOLD : wxFONTWEIGHT_NORMAL);
// Delete all old data
textures.clear();
glyphs.clear();
}
void OpenGLText::SetColour(agi::Color col) {
r = col.r / 255.f;
g = col.g / 255.f;
b = col.b / 255.f;
a = col.a / 255.f;
}
void OpenGLText::Print(const std::string &text, int x, int y) {
glEnable(GL_BLEND);
glEnable(GL_TEXTURE_2D);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
// Draw border
glColor4f(0.0f, 0.0f, 0.0f, 1.0f);
DrawString(text, x-1, y);
DrawString(text, x+1, y);
DrawString(text, x, y-1);
DrawString(text, x, y+1);
// Draw primary string
glColor4f(r, g, b, a);
DrawString(text, x, y);
// Disable blend
glDisable(GL_TEXTURE_2D);
glDisable(GL_BLEND);
}
void OpenGLText::DrawString(const std::string &text, int x, int y) {
for (char curChar : text) {
OpenGLTextGlyph const& glyph = GetGlyph(curChar);
glyph.Draw(x, y);
x += glyph.w;
}
}
void OpenGLText::GetExtent(std::string const& text, int &w, int &h) {
w = h = 0;
for (char curChar : text) {
OpenGLTextGlyph const& glyph = GetGlyph(curChar);
w += glyph.w;
h = std::max(h, glyph.h);
}
}
OpenGLTextGlyph const& OpenGLText::GetGlyph(int i) {
auto res = glyphs.find(i);
return res != glyphs.end() ? res->second : CreateGlyph(i);
}
OpenGLTextGlyph const& OpenGLText::CreateGlyph(int n) {
OpenGLTextGlyph &glyph = glyphs.insert(std::make_pair(n, OpenGLTextGlyph(n, font))).first->second;
// Insert into some texture
for (auto& texture : textures) {
if (texture.TryToInsert(glyph))
return glyph;
}
// No texture could fit it, create a new one
textures.emplace_back(glyph);
return glyph;
}