is there any tutorial on using buffersubdata

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forniteOP•4/3/23, 10:14 AM

this is a bit confusing

Ffornite is there any tutorial on using buffersubdata

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Lyris the Kitori•4/3/23, 10:14 AM

there is no need for one, its just a few extra parameters on bufferdata

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Aqua•4/3/23, 10:14 AM

it's just BufferData with an extra parameter

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Lyris the Kitori•4/3/23, 10:14 AM

the documentation explains it well

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Aqua•4/3/23, 10:14 AM

which specifies the offset in the buffer you want to update

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forniteOP•4/3/23, 10:14 AM

so do i fix buffersubdata instead of bufferdata

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Aqua•4/3/23, 10:15 AM

when using BufferSubData, you must first allocate a buffer with BufferData. you don't have to put anything inside the buffer, you just need to make sure you do that
once it's been allocated, you can call BufferSubData as many times as you want

AAqua which specifies the offset in the buffer you want to update

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forniteOP•4/3/23, 10:16 AM

whats the offset

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Aqua•4/3/23, 10:17 AM

this is why you create one large buffer that stores everything you're going to draw
then you use BufferSubData with an offset to update it

AAqua this is why you create one large buffer that stores everything you're going to d...

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forniteOP•4/3/23, 10:17 AM

ahhhhhhhhh

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forniteOP•4/3/23, 10:17 AM

i almost get it

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Aqua•4/3/23, 10:17 AM

offset in bytes into the buffer

AAqua offset in bytes into the buffer

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forniteOP•4/3/23, 10:17 AM

why would i need to do that

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Lyris the Kitori•4/3/23, 10:17 AM

to upload a single part of a larger buffer

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forniteOP•4/3/23, 10:17 AM

wait

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Aqua•4/3/23, 10:18 AM

so you can update subsections of the buffer with data
aka
BufferSubData lol

LLyris the Kitori to upload a single part of a larger buffer

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Lyris the Kitori•4/3/23, 10:18 AM

such as a single shape, in a buffer with many of them

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forniteOP•4/3/23, 10:18 AM

if i make like functions to draw texturres

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forniteOP•4/3/23, 10:18 AM

do i need to put it into these buffers too

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Lyris the Kitori•4/3/23, 10:18 AM

lets ignore texturing until you get the basics down lol

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Lyris the Kitori•4/3/23, 10:18 AM

thats a whole 'nother mess

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forniteOP•4/3/23, 10:18 AM

jesus

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Lyris the Kitori•4/3/23, 10:19 AM

texturing will just "make sense" once you get the concepts of buffers and vertex layouts and shaders down

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Lyris the Kitori•4/3/23, 10:19 AM

but for now, we shall ignore textures for our sanity, and yours

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forniteOP•4/3/23, 10:19 AM

HAHAHA

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forniteOP•4/3/23, 10:19 AM

hold on

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forniteOP•4/3/23, 10:19 AM

what makes my rectangles orange

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forniteOP•4/3/23, 10:19 AM

is it the shader

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Lyris the Kitori•4/3/23, 10:19 AM

your shader

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forniteOP•4/3/23, 10:19 AM

or is it like a default color

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Lyris the Kitori•4/3/23, 10:20 AM

look at your fragment shader

LLyris the Kitori your shader

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forniteOP•4/3/23, 10:20 AM

where do i specify the color orange though

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Lyris the Kitori•4/3/23, 10:20 AM

explain what it does to me

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forniteOP•4/3/23, 10:20 AM

ok one sec

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Lyris the Kitori•4/3/23, 10:20 AM

read through the shader code line by line, and write comments explaining it

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Lyris the Kitori•4/3/23, 10:20 AM

if you dont know something at all, just put a question mark

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Aqua•4/3/23, 10:20 AM

the tutorial on the website goes over exactly what the fragment shader does

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forniteOP•4/3/23, 10:22 AM

            const string fragmentCode = @"
                // the version of glsl
                #version 330 core 
                
                // i think out means to output something and out_color is the name of a variable?
                out vec4 out_color; 

                // main function
                void main()
                {
                    // is vec4 an RGBA value with the color?
                    out_color = vec4(1.0, 0.5, 0.2, 1.0);
                }
            ";

            const string fragmentCode = @"
                // the version of glsl
                #version 330 core 
                
                // i think out means to output something and out_color is the name of a variable?
                out vec4 out_color; 

                // main function
                void main()
                {
                    // is vec4 an RGBA value with the color?
                    out_color = vec4(1.0, 0.5, 0.2, 1.0);
                }
            ";

            const string fragmentCode = @"
                // the version of glsl
                #version 330 core 
                
                // i think out means to output something and out_color is the name of a variable?
                out vec4 out_color; 

                // main function
                void main()
                {
                    // is vec4 an RGBA value with the color?
                    out_color = vec4(1.0, 0.5, 0.2, 1.0);
                }
            ";

            const string fragmentCode = @"
                // the version of glsl
                #version 330 core 
                
                // i think out means to output something and out_color is the name of a variable?
                out vec4 out_color; 

                // main function
                void main()
                {
                    // is vec4 an RGBA value with the color?
                    out_color = vec4(1.0, 0.5, 0.2, 1.0);
                }
            ";

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Aqua•4/3/23, 10:23 AM

yes the vec4 contains the output color

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Aqua•4/3/23, 10:23 AM

in this case an orange

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Aqua•4/3/23, 10:23 AM

it's in RGBA format

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Lyris the Kitori•4/3/23, 10:23 AM

4 floats

AAqua the tutorial on the website goes over exactly what the fragment shader does

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forniteOP•4/3/23, 10:23 AM

if the fragment shader changes the colors of the pixels inside the shape

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forniteOP•4/3/23, 10:23 AM

what is the point of the vertex shader

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forniteOP•4/3/23, 10:23 AM

on the tutorial

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forniteOP•4/3/23, 10:23 AM

it said like rotations or something

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forniteOP•4/3/23, 10:23 AM

but what does that mean

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Aqua•4/3/23, 10:23 AM

the vertex shader tells the GPU where to place the vertices

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Aqua•4/3/23, 10:24 AM

so you can apply transformations to the vertices to place them in different points

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Aqua•4/3/23, 10:24 AM

in the tutorial we're just giving a very basic example so the vertex shader does very little

is there any tutorial on using buffersubdata

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