TextRenderer.cpp

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/* Copyright (C) 2012 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "precompiled.h"

#include "TextRenderer.h"

#include "lib/ogl.h"
#include "lib/res/graphics/unifont.h"
#include "ps/CStrIntern.h"
#include "ps/Font.h"

extern int g_xres, g_yres;

CTextRenderer::CTextRenderer(const CShaderProgramPtr& shader) :
    m_Shader(shader)
{
    ResetTransform();
    Color(CColor(1.0f, 1.0f, 1.0f, 1.0f));
    Font(L"sans-10");
}

void CTextRenderer::ResetTransform()
{
    m_Transform.SetIdentity();
    m_Transform.Scale(1.0f, -1.f, 1.0f);
    m_Transform.Translate(0.0f, (float)g_yres, -1000.0f);

    CMatrix3D proj;
    proj.SetOrtho(0.f, (float)g_xres, 0.f, (float)g_yres, -1.f, 1000.f);
    m_Transform = proj * m_Transform;
}

CMatrix3D CTextRenderer::GetTransform()
{
    return m_Transform;
}

void CTextRenderer::SetTransform(const CMatrix3D& transform)
{
    m_Transform = transform;
}

void CTextRenderer::Translate(float x, float y, float z)
{
    CMatrix3D m;
    m.SetTranslation(x, y, z);
    m_Transform = m_Transform * m;
}

void CTextRenderer::Color(const CColor& color)
{
    m_Color = color;
}

void CTextRenderer::Color(float r, float g, float b, float a)
{
    m_Color = CColor(r, g, b, a);
}

void CTextRenderer::Font(const CStrW& font)
{
    if (!m_Fonts[font])
        m_Fonts[font] = shared_ptr<CFont>(new CFont(font));

    m_Font = m_Fonts[font];
}

void CTextRenderer::PrintfAdvance(const wchar_t* fmt, ...)
{
    wchar_t buf[1024] = {0};

    va_list args;
    va_start(args, fmt);
    int ret = vswprintf(buf, ARRAY_SIZE(buf)-1, fmt, args);
    va_end(args);

    if (ret < 0)
        debug_printf(L"CTextRenderer::Printf vswprintf failed (buffer size exceeded?) - return value %d, errno %d\n", ret, errno);

    PutAdvance(buf);
}


void CTextRenderer::PrintfAt(float x, float y, const wchar_t* fmt, ...)
{
    wchar_t buf[1024] = {0};

    va_list args;
    va_start(args, fmt);
    int ret = vswprintf(buf, ARRAY_SIZE(buf)-1, fmt, args);
    va_end(args);

    if (ret < 0)
        debug_printf(L"CTextRenderer::PrintfAt vswprintf failed (buffer size exceeded?) - return value %d, errno %d\n", ret, errno);

    Put(x, y, buf);
}

void CTextRenderer::PutAdvance(const wchar_t* buf)
{
    Put(0.0f, 0.0f, buf);

    int w, h;
    m_Font->CalculateStringSize(buf, w, h);
    Translate((float)w, 0.0f, 0.0f);
}

void CTextRenderer::Put(float x, float y, const wchar_t* buf)
{
    if (buf[0] == 0)
        return; // empty string; don't bother storing

    CMatrix3D translate;
    translate.SetTranslation(x, y, 0.0f);

    SBatch batch;
    batch.transform = m_Transform * translate;
    batch.color = m_Color;
    batch.font = m_Font;
    batch.text = buf;
    m_Batches.push_back(batch);
}

struct t2f_v2i
{
    t2f_v2i() : u(0), v(0), x(0), y(0) { }
    float u, v;
    i16 x, y;
};

void CTextRenderer::Render()
{
    std::vector<u16> indexes;
    std::vector<t2f_v2i> vertexes;

    for (size_t i = 0; i < m_Batches.size(); ++i)
    {
        SBatch& batch = m_Batches[i];

        if (batch.text.empty()) // avoid zero-length arrays
            continue;

        const std::map<u16, UnifontGlyphData>& glyphs = batch.font->GetGlyphs();

        m_Shader->BindTexture(str_tex, batch.font->GetTexture());

        m_Shader->Uniform(str_transform, batch.transform);

        // ALPHA-only textures will have .rgb sampled as 0, so we need to
        // replace it with white (but not affect RGBA textures)
        if (batch.font->HasRGB())
            m_Shader->Uniform(str_colorAdd, CColor(0.0f, 0.0f, 0.0f, 0.0f));
        else
            m_Shader->Uniform(str_colorAdd, CColor(1.0f, 1.0f, 1.0f, 0.0f));

        m_Shader->Uniform(str_colorMul, batch.color);

        vertexes.clear();
        vertexes.resize(batch.text.size()*4);

        indexes.clear();
        indexes.resize(batch.text.size()*6);

        i16 x = 0;
        for (size_t i = 0; i < batch.text.size(); ++i)
        {
            std::map<u16, UnifontGlyphData>::const_iterator it = glyphs.find(batch.text[i]);

            if (it == glyphs.end())
                it = glyphs.find(0xFFFD); // Use the missing glyph symbol

            if (it == glyphs.end()) // Missing the missing glyph symbol - give up
                continue;

            const UnifontGlyphData& g = it->second;

            vertexes[i*4].u = g.u1;
            vertexes[i*4].v = g.v0;
            vertexes[i*4].x = g.x1 + x;
            vertexes[i*4].y = g.y0;

            vertexes[i*4+1].u = g.u0;
            vertexes[i*4+1].v = g.v0;
            vertexes[i*4+1].x = g.x0 + x;
            vertexes[i*4+1].y = g.y0;

            vertexes[i*4+2].u = g.u0;
            vertexes[i*4+2].v = g.v1;
            vertexes[i*4+2].x = g.x0 + x;
            vertexes[i*4+2].y = g.y1;

            vertexes[i*4+3].u = g.u1;
            vertexes[i*4+3].v = g.v1;
            vertexes[i*4+3].x = g.x1 + x;
            vertexes[i*4+3].y = g.y1;

            indexes[i*6+0] = i*4+0;
            indexes[i*6+1] = i*4+1;
            indexes[i*6+2] = i*4+2;
            indexes[i*6+3] = i*4+2;
            indexes[i*6+4] = i*4+3;
            indexes[i*6+5] = i*4+0;

            x += g.xadvance;
        }

        m_Shader->VertexPointer(2, GL_SHORT, sizeof(t2f_v2i), &vertexes[0].x);
        m_Shader->TexCoordPointer(GL_TEXTURE0, 2, GL_FLOAT, sizeof(t2f_v2i), &vertexes[0].u);

        glDrawElements(GL_TRIANGLES, indexes.size(), GL_UNSIGNED_SHORT, &indexes[0]);
    }

    m_Batches.clear();
}