james4k/gfx

Package gfx provides simple abstractions over OpenGL shaders and triangle-based geometry.

gfx's Issues

support instanced drawing

shader compile/link error output

Shader compile and link output should output to a user provided io.Writer, and return an error if errors were written, by...checking for "error" in the output? Or by calling glGetError()? Need to test.

Another thought: the OpenGL API just returns a big string for the output, so maybe we should just return a special error that you can type assert to to grab the log output string. An io.Writer might actually be nicer, though?

Shader.AssignUniforms: cache field offsets for each type

allow shaders with matching attributes to share GeometryLayouts

improve vertex attributes extensibility

Right now, we provide 4 user data slots, bunch of texcoord slots, etc. and it just feels really messy even though this is what most people do. Ideally, we need to find a more flexible and sensible approach.

document the field types that AssignUniforms takes

LayoutGeometry should return error

Main issue that can occur now is incompatible vertex formats between shader and geometry.

image.Uniform for 1x1 samplers

Shader.AssignUniforms needs finalizing

1. Needs to return an error. A lot of room for user error, where uniform names need to match the shader.
2. Recurse down embedded structs to find fields. (unless reflect already does this?)
3. Skip unexported fields, as they will panic.
4. Proper Sampler2D handling, allotting to the correct texture units.
5. Support for all other basic uniform types, such as float arrays from 1 to 4, and integers.
6. Consider values via reflect.Kind instead of type switch, as we only care about the primitive type.

fix gophercube example

call DrawArrays when lacking index buffer

api for 32-bit indices

Right now only 16-bit indices are supported, which is kind of bad but the API is simple.