aminal/vendor/github.com/4ydx/gltext/v4.1/shaders.go

71 lines
1.9 KiB
Go

// Copyright 2012 The go-gl Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package v41
import (
"errors"
"fmt"
"github.com/go-gl/gl/v4.1-core/gl"
"strings"
)
func NewProgram(vertexShaderSource, fragmentShaderSource string) (uint32, error) {
vertexShader, err := compileShader(vertexShaderSource, gl.VERTEX_SHADER)
if err != nil {
return 0, err
}
fragmentShader, err := compileShader(fragmentShaderSource, gl.FRAGMENT_SHADER)
if err != nil {
return 0, err
}
program := gl.CreateProgram()
gl.AttachShader(program, vertexShader)
gl.AttachShader(program, fragmentShader)
gl.LinkProgram(program)
var status int32
gl.GetProgramiv(program, gl.LINK_STATUS, &status)
if status == gl.FALSE {
var logLength int32
gl.GetProgramiv(program, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetProgramInfoLog(program, logLength, nil, gl.Str(log))
gl.DeleteProgram(program)
gl.DeleteShader(vertexShader)
gl.DeleteShader(fragmentShader)
return 0, errors.New(fmt.Sprintf("failed to link program: %v", log))
}
gl.DetachShader(program, vertexShader)
gl.DetachShader(program, fragmentShader)
gl.DeleteShader(vertexShader)
gl.DeleteShader(fragmentShader)
return program, nil
}
func compileShader(source string, shaderType uint32) (uint32, error) {
shader := gl.CreateShader(shaderType)
csource := gl.Str(source)
gl.ShaderSource(shader, 1, &csource, nil)
gl.CompileShader(shader)
var status int32
gl.GetShaderiv(shader, gl.COMPILE_STATUS, &status)
if status == gl.FALSE {
var logLength int32
gl.GetShaderiv(shader, gl.INFO_LOG_LENGTH, &logLength)
log := strings.Repeat("\x00", int(logLength+1))
gl.GetShaderInfoLog(shader, logLength, nil, gl.Str(log))
return 0, fmt.Errorf("failed to compile %v: %v", source, log)
}
return shader, nil
}