4jcraft/Minecraft.Client/UI/GuiComponent.cpp

#include "../Platform/stdafx.h"
#include "GuiComponent.h"
#include "../Rendering/Tesselator.h"

void GuiComponent::hLine(int x0, int x1, int y, int col) {
    if (x1 < x0) {
        int tmp = x0;
        x0 = x1;
        x1 = tmp;
    }
    fill(x0, y, x1 + 1, y + 1, col);
}

void GuiComponent::vLine(int x, int y0, int y1, int col) {
    if (y1 < y0) {
        int tmp = y0;
        y0 = y1;
        y1 = tmp;
    }
    fill(x, y0 + 1, x + 1, y1, col);
}

void GuiComponent::fill(int x0, int y0, int x1, int y1, int col) {
    if (x0 < x1) {
        int tmp = x0;
        x0 = x1;
        x1 = tmp;
    }
    if (y0 < y1) {
        int tmp = y0;
        y0 = y1;
        y1 = tmp;
    }
    float a = ((col >> 24) & 0xff) / 255.0f;
    float r = ((col >> 16) & 0xff) / 255.0f;
    float g = ((col >> 8) & 0xff) / 255.0f;
    float b = ((col) & 0xff) / 255.0f;
    Tesselator* t = Tesselator::getInstance();
    glEnable(GL_BLEND);
    glDisable(GL_TEXTURE_2D);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glColor4f(r, g, b, a);
    t->begin();
    t->vertex((float)(x0), (float)(y1), (float)(0));
    t->vertex((float)(x1), (float)(y1), (float)(0));
    t->vertex((float)(x1), (float)(y0), (float)(0));
    t->vertex((float)(x0), (float)(y0), (float)(0));
    t->end();
    glEnable(GL_TEXTURE_2D);
    glDisable(GL_BLEND);
}

void GuiComponent::fillGradient(int x0, int y0, int x1, int y1, int col1,
                                int col2) {
    float a1 = ((col1 >> 24) & 0xff) / 255.0f;
    float r1 = ((col1 >> 16) & 0xff) / 255.0f;
    float g1 = ((col1 >> 8) & 0xff) / 255.0f;
    float b1 = ((col1) & 0xff) / 255.0f;

    float a2 = ((col2 >> 24) & 0xff) / 255.0f;
    float r2 = ((col2 >> 16) & 0xff) / 255.0f;
    float g2 = ((col2 >> 8) & 0xff) / 255.0f;
    float b2 = ((col2) & 0xff) / 255.0f;
    glDisable(GL_TEXTURE_2D);
    glEnable(GL_BLEND);
    glDisable(GL_ALPHA_TEST);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glShadeModel(GL_SMOOTH);

    Tesselator* t = Tesselator::getInstance();
    t->begin();
    t->color(r1, g1, b1, a1);
    t->vertex((float)(x1), (float)(y0), blitOffset);
    t->vertex((float)(x0), (float)(y0), blitOffset);
    t->color(r2, g2, b2, a2);
    t->vertex((float)(x0), (float)(y1), blitOffset);
    t->vertex((float)(x1), (float)(y1), blitOffset);
    t->end();

    glShadeModel(GL_FLAT);
    glDisable(GL_BLEND);
    glEnable(GL_ALPHA_TEST);
    glEnable(GL_TEXTURE_2D);
}

GuiComponent::GuiComponent() { blitOffset = 0; }

void GuiComponent::drawCenteredString(Font* font, const std::wstring& str,
                                      int x, int y, int color) {
    font->drawShadow(str, x - (font->width(str)) / 2, y, color);
}

void GuiComponent::drawString(Font* font, const std::wstring& str, int x, int y,
                              int color) {
    font->drawShadow(str, x, y, color);
}

void GuiComponent::blit(int x, int y, int sx, int sy, int w, int h) {
    float us = 1 / 256.0f;
    float vs = 1 / 256.0f;
    Tesselator* t = Tesselator::getInstance();
    t->begin();

    // This is a bit of a mystery. In general this ought to be 0.5 to match the
    // centre of texels & pixels in the DX9 version of things. However, when
    // scaling the GUI by a factor of 1.5, I'm really not sure how exactly point
    // sampled rasterisation works, but when shifting by 0.5 we get a
    // discontinuity down the diagonal of quads. Setting this shift to 0.75 in
    // all cases seems to work fine.
    const float extraShift = 0.75f;

    // 4J - subtracting extraShift (actual screen pixels, so need to compensate
    // for physical & game width) from each x & y coordinate to compensate for
    // centre of pixels in directx vs openGL
    float dx = (extraShift * (float)Minecraft::GetInstance()->width) /
               (float)Minecraft::GetInstance()->width_phys;
    // 4J - Also factor in the scaling from gui coordinate space to the screen.
    // This varies based on user-selected gui scale, and whether we are in a
    // viewport mode or not
    dx /= Gui::currentGuiScaleFactor;
    float dy = extraShift / Gui::currentGuiScaleFactor;
    // Ensure that the x/y, width and height are actually pixel aligned at our
    // current scale factor - in particular, for split screen mode with the
    // default (3X) scale, we have an overall scale factor of 3 * 0.5 = 1.5, and
    // so any odd pixels won't align
    float fx = (floorf((float)x * Gui::currentGuiScaleFactor)) /
               Gui::currentGuiScaleFactor;
    float fy = (floorf((float)y * Gui::currentGuiScaleFactor)) /
               Gui::currentGuiScaleFactor;
    float fw = (floorf((float)w * Gui::currentGuiScaleFactor)) /
               Gui::currentGuiScaleFactor;
    float fh = (floorf((float)h * Gui::currentGuiScaleFactor)) /
               Gui::currentGuiScaleFactor;

    t->vertexUV(fx + 0 - dx, fy + fh - dy, (float)(blitOffset),
                (float)((sx + 0) * us), (float)((sy + h) * vs));
    t->vertexUV(fx + fw - dx, fy + fh - dy, (float)(blitOffset),
                (float)((sx + w) * us), (float)((sy + h) * vs));
    t->vertexUV(fx + fw - dx, fy + 0 - dy, (float)(blitOffset),
                (float)((sx + w) * us), (float)((sy + 0) * vs));
    t->vertexUV(fx + 0 - dx, fy + 0 - dy, (float)(blitOffset),
                (float)((sx + 0) * us), (float)((sy + 0) * vs));
    t->end();
}