but how does it know that variable is for the color and not something else
but how does it know that variable is for the color and not something else
Fwould this be how i would need to externally control a color in the shader?
Ayep, the
so you'd define vertex colors in your vertex buffer, set up the attribs, and then set this value in the vertex shader
in value in this case would come from the vertex shaderso you'd define vertex colors in your vertex buffer, set up the attribs, and then set this value in the vertex shader
Abased on what you're trying to do though it could be done with a
but vertex colors is what i'd advise doing
uniformbut vertex colors is what i'd advise doing
Aout variables in fragment shaders are always for color
Foh yeah im reading about those right now
Fis this right
Fso this would output my color which i input from my c# externally
Athat would work sure
just remember this only works if you do separate draw calls, uniforms have the same value throughout the draw call
this is why i'd advise using vertex colors, it allows you to change them even while still using one draw call
just remember this only works if you do separate draw calls, uniforms have the same value throughout the draw call
this is why i'd advise using vertex colors, it allows you to change them even while still using one draw call
Fyeah im doing separate draw calls
Amy sprite renderer passes through a bunch of vertex parameters, including stuff like rotation information. because of this I can draw up to 16384 sprites in a single draw call
Fmaybe one day ill figure out how to do all this in one draw call but im gonna stick to this for now cus it works
Fim still confused though
Fso the fragment shader
Fsets the color of every individual pixel
Fi get that
Fbut the vertex shader
Fsets the color of the vertices?
Fa vertice is just a corner though
Athe vertex shader determines what position on the screen each vertex is
Lonly 16384? pfft
Ait's an arbitrary limit i manually set
Amy engine is a 3D engine so there's no need to waste GPU memory for a bunch of sprites that will never be drawn
Abasically
vertex shader = position
fragment shader = color
vertex shader = position
fragment shader = color
FOH MY GOD
FIM SO HAPPY
FI DID IT
FI CAN DRAW MULTIPLE SHAPES AND I CAN HAVE THEM BE DIFFERENT COLORS
Fi simplified like 270 lines of code into like 15 lines of code
F
F
Five never been more happy to see some basic shapes on my screen
Five also made a thing for the coordinate system to be in pixels instead of floats
Fand instead of coming from the middle
Fthe coordinate system comes from the top left and increases towards the bottom right
Flike most game engines have it cus im used to that
Ayour life will be a lot easier once you get to transformations in the learnopengl tutorial
Fi will definitely read about that
Fdo i even wanna know how to draw a circle
Acircles are a lot harder. you either have to draw lots of small triangles, draw a circle texture, or do what I do which is to use an SDF which is a whole nother thing entirely
Fcould i make a program that basically creates an empty array and then goes along bit by bit by the circumference of the circle until it makes a full circle and comes back to the start
Fand with each iteration it stores that coordinate into the array and then uses that as a buffer
Ayou have to make sure it creates triangles
Agenerally for that i'd use a triangulation algorithm. but i don't know, i never even bothered doing that, I just use SDFs
Athe easiest thing to do though is almost certainly going to be to create a texture CPU side and then draw it
Awon't be particularly fast but the other two ways are vastly more complicated
Fah shit
F
Fon that note
Fmoving on to drawing textures
Ahttps://github.com/skyebird189/Silk.NET/blob/samples-textures/examples/CSharp/OpenGL%20Tutorials/Tutorial%201.3%20-%20Textures/Program.cs take a look at my fork, I've written a texture tutorial that doesn't use the GL abstractions