ebiten/internal/graphics/opengl/context.go

328 lines
8.7 KiB
Go

// Copyright 2014 Hajime Hoshi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// +build !js
package opengl
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
mgl "golang.org/x/mobile/gl"
)
type Texture mgl.Texture
type Framebuffer mgl.Framebuffer
type Shader mgl.Shader
type Program mgl.Program
type Buffer mgl.Texture
var ZeroFramebuffer Framebuffer
// TODO: Remove this after the GopherJS bug was fixed (#159)
func (p Program) Equals(other Program) bool {
return p == other
}
type UniformLocation mgl.Uniform
type AttribLocation mgl.Attrib
type ProgramID uint32
func GetProgramID(p Program) ProgramID {
return ProgramID(p.Value)
}
type context struct {
worker mgl.Worker
funcs chan func()
}
// TODO: This variable can be in the context struct.
var (
gl mgl.Context
)
func NewContext() *Context {
c := &Context{
Nearest: mgl.NEAREST,
Linear: mgl.LINEAR,
VertexShader: mgl.VERTEX_SHADER,
FragmentShader: mgl.FRAGMENT_SHADER,
ArrayBuffer: mgl.ARRAY_BUFFER,
ElementArrayBuffer: mgl.ELEMENT_ARRAY_BUFFER,
DynamicDraw: mgl.DYNAMIC_DRAW,
StaticDraw: mgl.STATIC_DRAW,
Triangles: mgl.TRIANGLES,
Lines: mgl.LINES,
}
c.funcs = make(chan func())
gl, c.worker = mgl.NewContext()
return c
}
func (c *Context) Loop() {
for {
select {
case <-c.worker.WorkAvailable():
c.worker.DoWork()
case f := <-c.funcs:
f()
}
}
}
func (c *Context) Init() {
// This initialization must be done after Loop is called.
// This is why Init is separated from NewContext.
// Textures' pixel formats are alpha premultiplied.
gl.Enable(mgl.BLEND)
gl.BlendFunc(mgl.ONE, mgl.ONE_MINUS_SRC_ALPHA)
}
func (c *Context) RunOnContextThread(f func()) {
ch := make(chan struct{})
c.funcs <- func() {
f()
close(ch)
}
<-ch
return
}
func (c *Context) Check() {
if e := gl.GetError(); e != mgl.NO_ERROR {
panic(fmt.Sprintf("check failed: %d", e))
}
}
func (c *Context) NewTexture(width, height int, pixels []uint8, filter Filter) (Texture, error) {
t := gl.CreateTexture()
if t.Value < 0 {
return Texture{}, errors.New("graphics: glGenTexture failed")
}
gl.PixelStorei(mgl.UNPACK_ALIGNMENT, 4)
gl.BindTexture(mgl.TEXTURE_2D, t)
gl.TexParameteri(mgl.TEXTURE_2D, mgl.TEXTURE_MAG_FILTER, int(filter))
gl.TexParameteri(mgl.TEXTURE_2D, mgl.TEXTURE_MIN_FILTER, int(filter))
var p []uint8
if pixels != nil {
p = pixels
}
gl.TexImage2D(mgl.TEXTURE_2D, 0, width, height, mgl.RGBA, mgl.UNSIGNED_BYTE, p)
return Texture(t), nil
}
func (c *Context) FramebufferPixels(f Framebuffer, width, height int) ([]uint8, error) {
gl.Flush()
gl.BindFramebuffer(mgl.FRAMEBUFFER, mgl.Framebuffer(f))
pixels := make([]uint8, 4*width*height)
gl.ReadPixels(pixels, 0, 0, width, height, mgl.RGBA, mgl.UNSIGNED_BYTE)
if e := gl.GetError(); e != mgl.NO_ERROR {
return nil, errors.New(fmt.Sprintf("graphics: glReadPixels: %d", e))
}
return pixels, nil
}
func (c *Context) BindTexture(t Texture) {
gl.BindTexture(mgl.TEXTURE_2D, mgl.Texture(t))
}
func (c *Context) DeleteTexture(t Texture) {
gl.DeleteTexture(mgl.Texture(t))
}
func (c *Context) TexSubImage2D(p []uint8, width, height int) {
gl.TexSubImage2D(mgl.TEXTURE_2D, 0, 0, 0, width, height, mgl.RGBA, mgl.UNSIGNED_BYTE, p)
}
func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
f := gl.CreateFramebuffer()
gl.BindFramebuffer(mgl.FRAMEBUFFER, f)
gl.FramebufferTexture2D(mgl.FRAMEBUFFER, mgl.COLOR_ATTACHMENT0, mgl.TEXTURE_2D, mgl.Texture(texture), 0)
s := gl.CheckFramebufferStatus(mgl.FRAMEBUFFER)
if s != mgl.FRAMEBUFFER_COMPLETE {
if s != 0 {
return Framebuffer{}, errors.New(fmt.Sprintf("graphics: creating framebuffer failed: %v", s))
}
if e := gl.GetError(); e != mgl.NO_ERROR {
return Framebuffer{}, errors.New(fmt.Sprintf("graphics: creating framebuffer failed: (glGetError) %d", e))
}
return Framebuffer{}, errors.New(fmt.Sprintf("graphics: creating framebuffer failed: unknown error"))
}
return Framebuffer(f), nil
}
func (c *Context) SetViewport(f Framebuffer, width, height int) error {
gl.Flush()
gl.BindFramebuffer(mgl.FRAMEBUFFER, mgl.Framebuffer(f))
if err := gl.CheckFramebufferStatus(mgl.FRAMEBUFFER); err != mgl.FRAMEBUFFER_COMPLETE {
if e := gl.GetError(); e != 0 {
return errors.New(fmt.Sprintf("graphics: glBindFramebuffer failed: %d", e))
}
return errors.New("graphics: glBindFramebuffer failed: the context is different?")
}
gl.Viewport(0, 0, width, height)
return nil
}
func (c *Context) FillFramebuffer(r, g, b, a float64) error {
gl.ClearColor(float32(r), float32(g), float32(b), float32(a))
gl.Clear(mgl.COLOR_BUFFER_BIT)
return nil
}
func (c *Context) DeleteFramebuffer(f Framebuffer) {
gl.DeleteFramebuffer(mgl.Framebuffer(f))
}
func (c *Context) NewShader(shaderType ShaderType, source string) (Shader, error) {
s := gl.CreateShader(mgl.Enum(shaderType))
if s.Value == 0 {
return Shader{}, errors.New("graphics: glCreateShader failed")
}
gl.ShaderSource(s, source)
gl.CompileShader(s)
v := gl.GetShaderi(s, mgl.COMPILE_STATUS)
if v == mgl.FALSE {
log := gl.GetShaderInfoLog(s)
return Shader{}, errors.New(fmt.Sprintf("graphics: shader compile failed: %s", log))
}
return Shader(s), nil
}
func (c *Context) DeleteShader(s Shader) {
gl.DeleteShader(mgl.Shader(s))
}
func (c *Context) GlslHighpSupported() bool {
return false
}
func (c *Context) NewProgram(shaders []Shader) (Program, error) {
p := gl.CreateProgram()
if p.Value == 0 {
return Program{}, errors.New("graphics: glCreateProgram failed")
}
for _, shader := range shaders {
gl.AttachShader(p, mgl.Shader(shader))
}
gl.LinkProgram(p)
v := gl.GetProgrami(p, mgl.LINK_STATUS)
if v == mgl.FALSE {
return Program{}, errors.New("graphics: program error")
}
return Program(p), nil
}
func (c *Context) UseProgram(p Program) {
gl.UseProgram(mgl.Program(p))
}
func (c *Context) GetUniformLocation(p Program, location string) UniformLocation {
u := UniformLocation(gl.GetUniformLocation(mgl.Program(p), location))
if u.Value == -1 {
panic("invalid uniform location: " + location)
}
return u
}
func (c *Context) UniformInt(p Program, location string, v int) {
gl.Uniform1i(gl.GetUniformLocation(mgl.Program(p), location), v)
}
func (c *Context) UniformFloats(p Program, location string, v []float32) {
l := gl.GetUniformLocation(mgl.Program(p), location)
switch len(v) {
case 4:
gl.Uniform4fv(l, v)
case 16:
gl.UniformMatrix4fv(l, v)
default:
panic("not reach")
}
}
func (c *Context) GetAttribLocation(p Program, location string) AttribLocation {
a := AttribLocation(gl.GetAttribLocation(mgl.Program(p), location))
if a.Value == ^uint(0) {
panic("invalid attrib location: " + location)
}
return a
}
func (c *Context) VertexAttribPointer(p Program, location string, normalize bool, stride int, size int, v int) {
l := c.GetAttribLocation(p, location)
gl.VertexAttribPointer(mgl.Attrib(l), size, mgl.SHORT, normalize, stride, v)
}
func (c *Context) EnableVertexAttribArray(p Program, location string) {
l := c.GetAttribLocation(p, location)
gl.EnableVertexAttribArray(mgl.Attrib(l))
}
func (c *Context) DisableVertexAttribArray(p Program, location string) {
l := c.GetAttribLocation(p, location)
gl.DisableVertexAttribArray(mgl.Attrib(l))
}
func (c *Context) NewBuffer(bufferType BufferType, v interface{}, bufferUsage BufferUsage) Buffer {
b := gl.CreateBuffer()
gl.BindBuffer(mgl.Enum(bufferType), b)
switch v := v.(type) {
case int:
gl.BufferInit(mgl.Enum(bufferType), v, mgl.Enum(bufferUsage))
return Buffer(b)
case []uint16:
case []float32:
default:
panic("not reach")
}
bt := &bytes.Buffer{}
if err := binary.Write(bt, binary.LittleEndian, v); err != nil {
panic(fmt.Sprintf("graphics: Binary error: %v", err))
}
gl.BufferData(mgl.Enum(bufferType), bt.Bytes(), mgl.Enum(bufferUsage))
return Buffer(b)
}
func (c *Context) BindElementArrayBuffer(b Buffer) {
gl.BindBuffer(mgl.ELEMENT_ARRAY_BUFFER, mgl.Buffer(b))
}
func (c *Context) BufferSubData(bufferType BufferType, data []int16) {
bt := &bytes.Buffer{}
if err := binary.Write(bt, binary.LittleEndian, data); err != nil {
panic(fmt.Sprintf("graphics: Binary error: %v", err))
}
gl.BufferSubData(mgl.Enum(bufferType), 0, bt.Bytes())
}
func (c *Context) DrawElements(mode Mode, len int) {
gl.DrawElements(mgl.Enum(mode), len, mgl.UNSIGNED_SHORT, 0)
}