[1.9] drawTexturedModalRect and other such draw commands

[WaffleMan0310]

Hello,

So I'll start off by saying hello to the forge community as I am new to modding. (I have tried in the past but it didn't stick) I have a solid foundation in Java, have done a lot of reading and what not on it, I feel as if I know enough to fluently program, it's just a matter of learning forge and rendering and such.

 

My issue is as follows, I am trying to render a texture that is 768 * 768 as the background for a gui (I know your supposed to have 256*256) so I have to rewrite drawTexturedModalRect to adapt to this. But being new to all of this rendering stuff such as U, V coordinates; which seem simple. Here's my code:

 

        double startX = (double)((float)mc.displayWidth / 2) - (((float)texWidth / 2));
        double startY = (double)((float)mc.displayHeight / 2) + (((float)texHeight / 2));
        Tessellator tessellator = Tessellator.getInstance();
        VertexBuffer vertexBuffer = tessellator.getBuffer();
        GlStateManager.disableFog();
        GlStateManager.disableLighting();
        GlStateManager.color(1.0F, 1.0F, 1.0F, 1.0F);
        mc.getTextureManager().bindTexture(background);
        vertexBuffer.begin(7, DefaultVertexFormats.POSITION_TEX);
        vertexBuffer.pos(startX, startY, 0).tex(0, 0).endVertex();
        vertexBuffer.pos(startX + texWidth, startY, 0).tex(1, 0).endVertex();
        vertexBuffer.pos(startX, startY + texHeight, 0).tex(0, 1).endVertex();
        vertexBuffer.pos(startX + texWidth, startY + texHeight, 0).tex(1, 1).endVertex();
        tessellator.draw();

 

What I am trying to: Well end of the day, I am trying to make a panel like the achievement panel in which you can click and drag through a larger texture to find information and I am currently rendering the frame this will be inside. I want it to be in the center of the screen reliably which is what I assume I will get if I divide the display width and height by 2 (+/- 1 of course) and then set that as the point to start drawing at. Then just telling it to go the texture width and height away from that point to render the rest of the texture. This is all just what I derived from looking at the built-in drawTexturedModalRect, however I find it kind of hard to read because of all of the casting.

 

Questions & Clarifications: So to my interpretation vertexBuffer.pos() takes an X and a Y, these being the location on the screen. vertexBuffer.tex() takes a U and a V of which is a value from 0 - 1 with 1 being the full texture. And vertexBuffer.endVertex() simply ending the declaration of a vertex. However in game when I right click the item this gui is bound to, nothing shows up and I can for the life of me figure out why. It's probably something huge that just hasn't hit me yet due my my ineptness in rendering.

 

Again, I know this is probably a noob question, I'm just looking to further educate myself on rendering and what not. So if someone would run through rendering in a bit of detail, not from just a code perspective like "Call this function and it takes these parameters, this is what these parameters are..." instead; this is what this does in-game and here's why. Or a place where I can find this information would be most appreciated.

 

Thanks, WaffleMan0310

[Ernio]

Go to Gui.class and scroll alllllll the waaaayy down (few last methods)

 

Oh... I forgot to answer questions...

Okay 1st: All (?) vertex formats in GL are anti-clockwise.

 

As to all other stuff... we need more direct question or at least "what you want" stuff

[WaffleMan0310]

Oh...wow. Thanks! I guess a good follow-up would be: Is there a built-in or conventional way for centering a drawn texture?

[tiffit]

Oh...wow. Thanks! I guess a good follow-up would be: Is there a built-in or conventional way for centering a drawn texture?

 

There is guiLeft and guiTop but I believe those are for normal sized (256x256) GUIs. You can just do:

width/2-768/2 for centering on x. Y is the same thing (except with height).

[WaffleMan0310]

As another follow-up, I got to the point in that I am rendering the frame correctly and got a system to cause the texture to move when the mouse is held down and moved. Here's the code:

 

public class GuiGuideBook extends GuiScreen{

    private static final ResourceLocation background = new ResourceLocation(Reference.MODID, ResourceHelper.GUIDEBOOK_BACKGROUND);
    private static final ResourceLocation frame = new ResourceLocation(Reference.MODID, ResourceHelper.GUIDEBOOK_FRAME);
    private int frameWidth;
    private int frameHeight;
    private int mouseStartX;
    private int mouseStartY;
    private int mouseDisplacementX;
    private int mouseDisplacementY;
    private int backgroundX;
    private int backgroundY;

    public GuiGuideBook() {
        setGuiSize(512, 512);
    }

    @Override
    public void initGui() {
        this.frameWidth = (int)(width * 1.1);
        this.frameHeight = (int)(height * 1.92);
    }
    @Override
    public void updateScreen() {

    }
    @Override
    protected void mouseClicked(int mouseX, int mouseY, int mouseButton) {
        this.mouseStartX = mouseX;
        this.mouseStartY = mouseY;
    }

    @Override
    protected void mouseReleased(int mouseX, int mouseY, int mouseButton) {
        backgroundX += mouseDisplacementX;
        backgroundY += mouseDisplacementY;
        mouseDisplacementX = 0;
        mouseDisplacementY = 0;
    }

    @Override
    protected void mouseClickMove(int mouseX, int mouseY, int clickedMouseButton, long timeSinceLastClick) {
        this.mouseDisplacementX =  mouseX - mouseStartX;
        this.mouseDisplacementY = mouseY - mouseStartY;

    }
    @Override
    public void drawScreen(int mouseX, int mouseY, float partialTicks) {
        drawMovingBackground();
        drawFrame();
    }
    @Override
    public void onGuiClosed() {

    }
    @Override
    public boolean doesGuiPauseGame() {
        return false;
    }
    public void drawMovingBackground() {
        GlStateManager.disableFog();
        GlStateManager.disableLighting();
        GlStateManager.color(1.0F, 1.0F, 1.0F, 1.0F);
        mc.getTextureManager().bindTexture(background);
        drawModalRectWithCustomSizedTexture(0, 0, 1.0F - (float) (backgroundX + mouseDisplacementX), 1.0F - (float) (backgroundY + mouseDisplacementY), frameWidth, frameHeight, 1280, 720);
    }
    public void drawFrame() {
        int startX = Math.round(((float)width / 2) - ((float) frameWidth / 2));
        int startY = Math.round(((float)height / 2) - ((float) frameHeight / 2));
        GlStateManager.disableFog();
        GlStateManager.disableLighting();
        GlStateManager.color(1.0F, 1.0F, 1.0F, 1.0F);
        mc.getTextureManager().bindTexture(frame);
        drawScaledCustomSizeModalRect(startX, startY - 5, 0, 0, 768, 768, frameWidth, frameHeight, 768, 768);
    }
}

 

The only issue is making the moving background texture contained in the frame. Currently the frame is rendered over the background and the background takes up the whole screen. I tried looking at the achievement gui class and found that achievement was readable, but it seemed to only be for adding the achievements themselves. While GuiAchievements appears to be the class that generates the gui itself, and is full of a bunch of "field_146567_u" type variables. Here is an example of what it looks like in game: http://imgur.com/qqmLnv4

 

The space background scrolls just like the achievement panel does, I just need some education on how exactly I would make a "window" to see said background.

 

Any help would be most appreciated!

[Ernio]

Well, there is normal, prefered way:

Simply start drawing BG from x/y and end at u/v. It's REALLY simple math, just use your brain.

 

Tricky way:

Use GL to cut frame for you.

GL11.glEnable(GL11.GL_SCISSOR_TEST);
GL11.glScissor(x, y, w, h);
// YOUR CODE (everything that should be cut).
GL11.glDisable(GL11.GL_SCISSOR_TEST);

 

Note that direct GL operation will need you to do some scaling stuff on those x,y,w,h params.

This is what you can use:

ScaledResolution res = new ScaledResolution(this.mc);
double scaleW = this.mc.displayWidth / res.getScaledWidth_double();
double scaleH = this.mc.displayHeight / res.getScaledHeight_double();

 

Math I am leaving as exerice.

 

EDIT

 

But seriously - USE 1st one!