Files
gio/internal/glimpl/util.go
T
Elias Naur bfe2d04c60 gpu,app,internal/glimpl: update GL backend for the compute renderer
Modern graphics APIs have immutable objects, with mutable data. For example,
a texture's dimensions are immutable, while the texture contents is not.
Change the GPU API abstraction to match.

Clearing a Texture is convenient to do with a plain []byte. Generalize
Texture.Upload to take a plain byte slice and introduce a helper function for
uploading *image.RGBA data.

Add TextureFormatRGBA8 a format for the linear RGB colorspace.

Add OpenGL ES 3.1 functions for compute programs.

Signed-off-by: Elias Naur <mail@eliasnaur.com>
2020-12-31 17:21:35 +01:00

88 lines
2.5 KiB
Go

// SPDX-License-Identifier: Unlicense OR MIT
package glimpl
import (
"errors"
"fmt"
"strings"
)
func CreateProgram(ctx *Functions, vsSrc, fsSrc string, attribs []string) (Program, error) {
vs, err := createShader(ctx, VERTEX_SHADER, vsSrc)
if err != nil {
return Program{}, err
}
defer ctx.DeleteShader(vs)
fs, err := createShader(ctx, FRAGMENT_SHADER, fsSrc)
if err != nil {
return Program{}, err
}
defer ctx.DeleteShader(fs)
prog := ctx.CreateProgram()
if !prog.Valid() {
return Program{}, errors.New("glCreateProgram failed")
}
ctx.AttachShader(prog, vs)
ctx.AttachShader(prog, fs)
for i, a := range attribs {
ctx.BindAttribLocation(prog, Attrib(i), a)
}
ctx.LinkProgram(prog)
if ctx.GetProgrami(prog, LINK_STATUS) == 0 {
log := ctx.GetProgramInfoLog(prog)
ctx.DeleteProgram(prog)
return Program{}, fmt.Errorf("program link failed: %s", strings.TrimSpace(log))
}
return prog, nil
}
func CreateComputeProgram(ctx *Functions, src string) (Program, error) {
cs, err := createShader(ctx, COMPUTE_SHADER, src)
if err != nil {
return Program{}, err
}
defer ctx.DeleteShader(cs)
prog := ctx.CreateProgram()
if !prog.Valid() {
return Program{}, errors.New("glCreateProgram failed")
}
ctx.AttachShader(prog, cs)
ctx.LinkProgram(prog)
if ctx.GetProgrami(prog, LINK_STATUS) == 0 {
log := ctx.GetProgramInfoLog(prog)
ctx.DeleteProgram(prog)
return Program{}, fmt.Errorf("program link failed: %s", strings.TrimSpace(log))
}
return prog, nil
}
func createShader(ctx *Functions, typ Enum, src string) (Shader, error) {
sh := ctx.CreateShader(typ)
if !sh.Valid() {
return Shader{}, errors.New("glCreateShader failed")
}
ctx.ShaderSource(sh, src)
ctx.CompileShader(sh)
if ctx.GetShaderi(sh, COMPILE_STATUS) == 0 {
log := ctx.GetShaderInfoLog(sh)
ctx.DeleteShader(sh)
return Shader{}, fmt.Errorf("shader compilation failed: %s", strings.TrimSpace(log))
}
return sh, nil
}
func ParseGLVersion(glVer string) (version [2]int, gles bool, err error) {
var ver [2]int
if _, err := fmt.Sscanf(glVer, "OpenGL ES %d.%d", &ver[0], &ver[1]); err == nil {
return ver, true, nil
} else if _, err := fmt.Sscanf(glVer, "WebGL %d.%d", &ver[0], &ver[1]); err == nil {
// WebGL major version v corresponds to OpenGL ES version v + 1
ver[0]++
return ver, true, nil
} else if _, err := fmt.Sscanf(glVer, "%d.%d", &ver[0], &ver[1]); err == nil {
return ver, false, nil
}
return ver, false, fmt.Errorf("failed to parse OpenGL ES version (%s)", glVer)
}