ebiten/internal/graphics/opengl/context.go
2015-07-22 23:28:15 +09:00

305 lines
7.9 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 (
"errors"
"fmt"
"github.com/go-gl/gl/v2.1/gl"
)
type Texture uint32
type Framebuffer uint32
type Shader uint32
type Program uint32
type Buffer uint32
var ZeroFramebuffer Framebuffer = 0
// TODO: Remove this after the GopherJS bug was fixed (#159)
func (p Program) Equals(other Program) bool {
return p == other
}
type UniformLocation int32
type AttribLocation int32
type ProgramID int
func GetProgramID(p Program) ProgramID {
return ProgramID(p)
}
type context struct{}
func NewContext() *Context {
c := &Context{
Nearest: gl.NEAREST,
Linear: gl.LINEAR,
VertexShader: gl.VERTEX_SHADER,
FragmentShader: gl.FRAGMENT_SHADER,
ArrayBuffer: gl.ARRAY_BUFFER,
ElementArrayBuffer: gl.ELEMENT_ARRAY_BUFFER,
DynamicDraw: gl.DYNAMIC_DRAW,
StaticDraw: gl.STATIC_DRAW,
Triangles: gl.TRIANGLES,
Lines: gl.LINES,
}
c.init()
return c
}
func (c *Context) init() {
if err := gl.Init(); err != nil {
panic(err)
}
// Textures' pixel formats are alpha premultiplied.
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
}
func (c *Context) Check() {
if e := gl.GetError(); e != gl.NO_ERROR {
panic(fmt.Sprintf("check failed: %d", e))
}
}
func (c *Context) NewTexture(width, height int, pixels []uint8, filter Filter) (Texture, error) {
var t uint32
gl.GenTextures(1, &t)
if t < 0 {
return 0, errors.New("glGenTexture failed")
}
gl.PixelStorei(gl.UNPACK_ALIGNMENT, 4)
gl.BindTexture(gl.TEXTURE_2D, t)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, int32(filter))
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, int32(filter))
var p interface{}
if pixels != nil {
p = pixels
}
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, int32(width), int32(height), 0, gl.RGBA, gl.UNSIGNED_BYTE, gl.Ptr(p))
return Texture(t), nil
}
func (c *Context) FramebufferPixels(f Framebuffer, width, height int) ([]uint8, error) {
gl.Flush()
gl.BindFramebuffer(gl.FRAMEBUFFER, uint32(f))
pixels := make([]uint8, 4*width*height)
gl.ReadPixels(0, 0, int32(width), int32(height), gl.RGBA, gl.UNSIGNED_BYTE, gl.Ptr(pixels))
if e := gl.GetError(); e != gl.NO_ERROR {
return nil, errors.New(fmt.Sprintf("glReadPixels: %d", e))
}
return pixels, nil
}
func (c *Context) BindTexture(t Texture) {
gl.BindTexture(gl.TEXTURE_2D, uint32(t))
}
func (c *Context) DeleteTexture(t Texture) {
tt := uint32(t)
gl.DeleteTextures(1, &tt)
}
func (c *Context) TexSubImage2D(p []uint8, width, height int) {
gl.TexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, int32(width), int32(height), gl.RGBA, gl.UNSIGNED_BYTE, gl.Ptr(p))
}
func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
var f uint32
gl.GenFramebuffers(1, &f)
gl.BindFramebuffer(gl.FRAMEBUFFER, f)
gl.FramebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, uint32(texture), 0)
if gl.CheckFramebufferStatus(gl.FRAMEBUFFER) != gl.FRAMEBUFFER_COMPLETE {
return 0, errors.New("creating framebuffer failed")
}
return Framebuffer(f), nil
}
func (c *Context) SetViewport(f Framebuffer, width, height int) error {
gl.Flush()
gl.BindFramebuffer(gl.FRAMEBUFFER, uint32(f))
if err := gl.CheckFramebufferStatus(gl.FRAMEBUFFER); err != gl.FRAMEBUFFER_COMPLETE {
if e := gl.GetError(); e != 0 {
return errors.New(fmt.Sprintf("glBindFramebuffer failed: %d", e))
}
return errors.New("glBindFramebuffer failed: the context is different?")
}
gl.Viewport(0, 0, int32(width), int32(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(gl.COLOR_BUFFER_BIT)
return nil
}
func (c *Context) DeleteFramebuffer(f Framebuffer) {
ff := uint32(f)
gl.DeleteFramebuffers(1, &ff)
}
func (c *Context) NewShader(shaderType ShaderType, source string) (Shader, error) {
s := gl.CreateShader(uint32(shaderType))
if s == 0 {
return 0, errors.New("glCreateShader failed")
}
glSource := gl.Str(source + "\x00")
gl.ShaderSource(uint32(s), 1, &glSource, nil)
gl.CompileShader(s)
var v int32
gl.GetShaderiv(s, gl.COMPILE_STATUS, &v)
if v == gl.FALSE {
log := []uint8{}
gl.GetShaderiv(uint32(s), gl.INFO_LOG_LENGTH, &v)
if v != 0 {
log = make([]uint8, int(v))
gl.GetShaderInfoLog(uint32(s), v, nil, (*uint8)(gl.Ptr(log)))
}
return 0, errors.New(fmt.Sprintf("shader compile failed: %s", string(log)))
}
return Shader(s), nil
}
func (c *Context) DeleteShader(s Shader) {
gl.DeleteShader(uint32(s))
}
func (c *Context) GlslHighpSupported() bool {
return false
}
func (c *Context) NewProgram(shaders []Shader) (Program, error) {
p := gl.CreateProgram()
if p == 0 {
return 0, errors.New("glCreateProgram failed")
}
for _, shader := range shaders {
gl.AttachShader(p, uint32(shader))
}
gl.LinkProgram(p)
var v int32
gl.GetProgramiv(p, gl.LINK_STATUS, &v)
if v == gl.FALSE {
return 0, errors.New("program error")
}
return Program(p), nil
}
func (c *Context) UseProgram(p Program) {
gl.UseProgram(uint32(p))
}
func (c *Context) GetUniformLocation(p Program, location string) UniformLocation {
u := UniformLocation(gl.GetUniformLocation(uint32(p), gl.Str(location+"\x00")))
if u == -1 {
panic("invalid uniform location: " + location)
}
return u
}
func (c *Context) UniformInt(p Program, location string, v int) {
l := int32(GetUniformLocation(c, p, location))
gl.Uniform1i(l, int32(v))
}
func (c *Context) UniformFloats(p Program, location string, v []float32) {
l := int32(GetUniformLocation(c, p, location))
switch len(v) {
case 4:
gl.Uniform4fv(l, 1, (*float32)(gl.Ptr(v)))
case 16:
gl.UniformMatrix4fv(l, 1, false, (*float32)(gl.Ptr(v)))
default:
panic("not reach")
}
}
func (c *Context) GetAttribLocation(p Program, location string) AttribLocation {
a := AttribLocation(gl.GetAttribLocation(uint32(p), gl.Str(location+"\x00")))
if a == -1 {
panic("invalid attrib location: " + location)
}
return a
}
func (c *Context) VertexAttribPointer(p Program, location string, signed bool, normalize bool, stride int, size int, v int) {
l := GetAttribLocation(c, p, location)
t := gl.SHORT
if !signed {
t = gl.UNSIGNED_SHORT
}
gl.VertexAttribPointer(uint32(l), int32(size), uint32(t), normalize, int32(stride), gl.PtrOffset(v))
}
func (c *Context) EnableVertexAttribArray(p Program, location string) {
l := GetAttribLocation(c, p, location)
gl.EnableVertexAttribArray(uint32(l))
}
func (c *Context) DisableVertexAttribArray(p Program, location string) {
l := GetAttribLocation(c, p, location)
gl.DisableVertexAttribArray(uint32(l))
}
func (c *Context) NewBuffer(bufferType BufferType, v interface{}, bufferUsage BufferUsage) Buffer {
var b uint32
gl.GenBuffers(1, &b)
gl.BindBuffer(uint32(bufferType), b)
size := 0
ptr := v
switch v := v.(type) {
case int:
size = v
ptr = nil
case []uint16:
size = 2 * len(v)
case []float32:
size = 4 * len(v)
default:
panic("not reach")
}
gl.BufferData(uint32(bufferType), size, gl.Ptr(ptr), uint32(bufferUsage))
return Buffer(b)
}
func (c *Context) BindElementArrayBuffer(b Buffer) {
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, uint32(b))
}
func (c *Context) BufferSubData(bufferType BufferType, data []int16) {
const int16Size = 2
gl.BufferSubData(uint32(bufferType), 0, int16Size*len(data), gl.Ptr(data))
}
func (c *Context) DrawElements(mode Mode, len int) {
gl.DrawElements(uint32(mode), int32(len), gl.UNSIGNED_SHORT, gl.PtrOffset(0))
}