ebiten/internal/graphicsdriver/opengl/context_js.go

602 lines
17 KiB
Go
Raw Normal View History

2014-12-31 13:55:40 +01:00
// 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.
package opengl
import (
"errors"
"fmt"
"syscall/js"
2018-10-28 12:42:57 +01:00
2020-10-03 19:35:13 +02:00
"github.com/hajimehoshi/ebiten/v2/internal/driver"
"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl/gles"
2020-10-03 19:35:13 +02:00
"github.com/hajimehoshi/ebiten/v2/internal/jsutil"
"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
"github.com/hajimehoshi/ebiten/v2/internal/web"
2014-12-31 13:55:40 +01:00
)
type (
2018-11-04 11:46:20 +01:00
textureNative js.Value
framebufferNative js.Value
shader js.Value
buffer js.Value
uniformLocation js.Value
2014-12-31 13:55:40 +01:00
attribLocation int
programID int
2018-10-29 17:52:59 +01:00
program struct {
value js.Value
id programID
}
)
2015-01-12 15:16:34 +01:00
func (t textureNative) equal(rhs textureNative) bool {
return js.Value(t).Equal(js.Value(rhs))
}
func (f framebufferNative) equal(rhs framebufferNative) bool {
return js.Value(f).Equal(js.Value(rhs))
}
func (s shader) equal(rhs shader) bool {
return js.Value(s).Equal(js.Value(rhs))
}
func (b buffer) equal(rhs buffer) bool {
return js.Value(b).Equal(js.Value(rhs))
}
func (u uniformLocation) equal(rhs uniformLocation) bool {
return js.Value(u).Equal(js.Value(rhs))
}
func (p program) equal(rhs program) bool {
return p.value.Equal(rhs.value) && p.id == rhs.id
}
2018-11-04 11:46:20 +01:00
var InvalidTexture = textureNative(js.Null())
var invalidUniform = uniformLocation(js.Null())
2018-10-29 17:52:59 +01:00
func getProgramID(p program) programID {
return p.id
2015-01-12 15:16:34 +01:00
}
const (
zero = operation(gles.ZERO)
one = operation(gles.ONE)
srcAlpha = operation(gles.SRC_ALPHA)
dstAlpha = operation(gles.DST_ALPHA)
oneMinusSrcAlpha = operation(gles.ONE_MINUS_SRC_ALPHA)
oneMinusDstAlpha = operation(gles.ONE_MINUS_DST_ALPHA)
dstColor = operation(gles.DST_COLOR)
)
var (
isWebGL2Available = !forceWebGL1 && (js.Global().Get("WebGL2RenderingContext").Truthy() || js.Global().Get("go2cpp").Truthy())
2021-01-04 18:07:30 +01:00
needsRestoring = !web.IsMobileBrowser() && !js.Global().Get("go2cpp").Truthy()
)
type contextImpl struct {
gl *gl
2016-05-31 19:33:31 +02:00
lastProgramID programID
2014-12-31 13:55:40 +01:00
}
func (c *context) initGL() {
var gl js.Value
// TODO: Define id?
if doc := js.Global().Get("document"); doc.Truthy() {
canvas := doc.Call("querySelector", "canvas")
attr := js.Global().Get("Object").New()
attr.Set("alpha", true)
attr.Set("premultipliedAlpha", true)
if isWebGL2Available {
gl = canvas.Call("getContext", "webgl2", attr)
} else {
gl = canvas.Call("getContext", "webgl", attr)
if !gl.Truthy() {
gl = canvas.Call("getContext", "experimental-webgl", attr)
if !gl.Truthy() {
panic("opengl: getContext failed")
}
}
}
} else if go2cpp := js.Global().Get("go2cpp"); go2cpp.Truthy() {
gl = go2cpp.Get("gl")
2015-01-27 14:02:23 +01:00
}
c.gl = newGL(gl)
2014-12-31 13:55:40 +01:00
}
func (c *context) reset() error {
2016-06-09 18:19:10 +02:00
c.locationCache = newLocationCache()
2018-11-04 11:46:20 +01:00
c.lastTexture = textureNative(js.Null())
c.lastFramebuffer = framebufferNative(js.Null())
2016-06-09 18:19:10 +02:00
c.lastViewportWidth = 0
c.lastViewportHeight = 0
c.lastCompositeMode = driver.CompositeModeUnknown
c.initGL()
if c.gl.isContextLost.Invoke().Bool() {
return driver.GraphicsNotReady
}
2016-06-09 18:19:10 +02:00
gl := c.gl
gl.enable.Invoke(gles.BLEND)
gl.enable.Invoke(gles.SCISSOR_TEST)
c.blendFunc(driver.CompositeModeSourceOver)
f := gl.getParameter.Invoke(gles.FRAMEBUFFER_BINDING)
c.screenFramebuffer = framebufferNative(f)
if !isWebGL2Available {
gl.getExtension.Invoke("OES_standard_derivatives")
}
return nil
2016-06-09 18:19:10 +02:00
}
func (c *context) blendFunc(mode driver.CompositeMode) {
if c.lastCompositeMode == mode {
2016-02-28 17:44:09 +01:00
return
}
c.lastCompositeMode = mode
2018-10-28 12:42:57 +01:00
s, d := mode.Operations()
s2, d2 := convertOperation(s), convertOperation(d)
gl := c.gl
gl.blendFunc.Invoke(int(s2), int(d2))
2014-12-31 13:55:40 +01:00
}
func (c *context) scissor(x, y, width, height int) {
gl := c.gl
gl.scissor.Invoke(x, y, width, height)
}
func (c *context) newTexture(width, height int) (textureNative, error) {
2014-12-31 13:55:40 +01:00
gl := c.gl
t := gl.createTexture.Invoke()
if !t.Truthy() {
2018-11-04 11:46:20 +01:00
return textureNative(js.Null()), errors.New("opengl: glGenTexture failed")
2014-12-31 13:55:40 +01:00
}
gl.pixelStorei.Invoke(gles.UNPACK_ALIGNMENT, 4)
2018-11-04 11:46:20 +01:00
c.bindTexture(textureNative(t))
2014-12-31 13:55:40 +01:00
gl.texParameteri.Invoke(gles.TEXTURE_2D, gles.TEXTURE_MAG_FILTER, gles.NEAREST)
gl.texParameteri.Invoke(gles.TEXTURE_2D, gles.TEXTURE_MIN_FILTER, gles.NEAREST)
gl.texParameteri.Invoke(gles.TEXTURE_2D, gles.TEXTURE_WRAP_S, gles.CLAMP_TO_EDGE)
gl.texParameteri.Invoke(gles.TEXTURE_2D, gles.TEXTURE_WRAP_T, gles.CLAMP_TO_EDGE)
2014-12-31 13:55:40 +01:00
2018-09-28 19:20:02 +02:00
// Firefox warns the usage of textures without specifying pixels (#629)
//
// Error: WebGL warning: drawElements: This operation requires zeroing texture data. This is slow.
//
// In Ebiten, textures are filled with pixels laster by the filter that ignores destination, so it is fine
// to leave textures as uninitialized here. Rather, extra memory allocating for initialization should be
// avoided.
gl.texImage2D.Invoke(gles.TEXTURE_2D, 0, gles.RGBA, width, height, 0, gles.RGBA, gles.UNSIGNED_BYTE, nil)
2014-12-31 13:55:40 +01:00
2018-11-04 11:46:20 +01:00
return textureNative(t), nil
2014-12-31 13:55:40 +01:00
}
func (c *context) bindFramebufferImpl(f framebufferNative) {
2015-02-19 18:02:23 +01:00
gl := c.gl
gl.bindFramebuffer.Invoke(gles.FRAMEBUFFER, js.Value(f))
2015-02-19 18:02:23 +01:00
}
func (c *context) framebufferPixels(f *framebuffer, width, height int) []byte {
2014-12-31 13:55:40 +01:00
gl := c.gl
c.bindFramebuffer(f.native)
l := 4 * width * height
p := jsutil.TemporaryUint8Array(l, nil)
gl.readPixels.Invoke(0, 0, width, height, gles.RGBA, gles.UNSIGNED_BYTE, p)
return jsutil.Uint8ArrayToSlice(p, l)
2014-12-31 13:55:40 +01:00
}
func (c *context) framebufferPixelsToBuffer(f *framebuffer, buffer buffer, width, height int) {
gl := c.gl
c.bindFramebuffer(f.native)
gl.bindBuffer.Invoke(gles.PIXEL_PACK_BUFFER, js.Value(buffer))
// void gl.readPixels(x, y, width, height, format, type, GLintptr offset);
gl.readPixels.Invoke(0, 0, width, height, gles.RGBA, gles.UNSIGNED_BYTE, 0)
gl.bindBuffer.Invoke(gles.PIXEL_PACK_BUFFER, nil)
}
func (c *context) activeTexture(idx int) {
gl := c.gl
gl.activeTexture.Invoke(gles.TEXTURE0 + idx)
}
func (c *context) bindTextureImpl(t textureNative) {
2014-12-31 13:55:40 +01:00
gl := c.gl
gl.bindTexture.Invoke(gles.TEXTURE_2D, js.Value(t))
2014-12-31 13:55:40 +01:00
}
func (c *context) deleteTexture(t textureNative) {
2014-12-31 13:55:40 +01:00
gl := c.gl
if !gl.isTexture.Invoke(js.Value(t)).Bool() {
return
}
if c.lastTexture.equal(t) {
2018-11-04 11:46:20 +01:00
c.lastTexture = textureNative(js.Null())
}
gl.deleteTexture.Invoke(js.Value(t))
2014-12-31 13:55:40 +01:00
}
func (c *context) isTexture(t textureNative) bool {
// isTexture should not be called to detect context-lost since this performance is not good (#1175).
panic("opengl: isTexture is not implemented")
2016-06-12 16:54:36 +02:00
}
func (c *context) newFramebuffer(t textureNative) (framebufferNative, error) {
2014-12-31 13:55:40 +01:00
gl := c.gl
f := gl.createFramebuffer.Invoke()
c.bindFramebuffer(framebufferNative(f))
2014-12-31 13:55:40 +01:00
gl.framebufferTexture2D.Invoke(gles.FRAMEBUFFER, gles.COLOR_ATTACHMENT0, gles.TEXTURE_2D, js.Value(t), 0)
if s := gl.checkFramebufferStatus.Invoke(gles.FRAMEBUFFER); s.Int() != gles.FRAMEBUFFER_COMPLETE {
return framebufferNative(js.Null()), errors.New(fmt.Sprintf("opengl: creating framebuffer failed: %d", s.Int()))
2014-12-31 13:55:40 +01:00
}
return framebufferNative(f), nil
2014-12-31 13:55:40 +01:00
}
func (c *context) setViewportImpl(width, height int) {
gl := c.gl
gl.viewport.Invoke(0, 0, width, height)
2014-12-31 13:55:40 +01:00
}
func (c *context) deleteFramebuffer(f framebufferNative) {
2014-12-31 13:55:40 +01:00
gl := c.gl
if !gl.isFramebuffer.Invoke(js.Value(f)).Bool() {
return
}
2016-07-06 19:08:28 +02:00
// If a framebuffer to be deleted is bound, a newly bound framebuffer
// will be a default framebuffer.
// https://www.khronos.org/opengles/sdk/docs/man/xhtml/glDeleteFramebuffers.xml
if c.lastFramebuffer.equal(f) {
c.lastFramebuffer = framebufferNative(js.Null())
c.lastViewportWidth = 0
c.lastViewportHeight = 0
}
gl.deleteFramebuffer.Invoke(js.Value(f))
2014-12-31 13:55:40 +01:00
}
func (c *context) newVertexShader(source string) (shader, error) {
return c.newShader(gles.VERTEX_SHADER, source)
}
func (c *context) newFragmentShader(source string) (shader, error) {
return c.newShader(gles.FRAGMENT_SHADER, source)
}
func (c *context) newShader(shaderType int, source string) (shader, error) {
2014-12-31 13:55:40 +01:00
gl := c.gl
s := gl.createShader.Invoke(int(shaderType))
if !s.Truthy() {
2018-10-29 17:52:59 +01:00
return shader(js.Null()), fmt.Errorf("opengl: glCreateShader failed: shader type: %d", shaderType)
2014-12-31 13:55:40 +01:00
}
gl.shaderSource.Invoke(js.Value(s), source)
gl.compileShader.Invoke(js.Value(s))
2014-12-31 13:55:40 +01:00
if !gl.getShaderParameter.Invoke(js.Value(s), gles.COMPILE_STATUS).Bool() {
log := gl.getShaderInfoLog.Invoke(js.Value(s))
2018-10-29 17:52:59 +01:00
return shader(js.Null()), fmt.Errorf("opengl: shader compile failed: %s", log)
2014-12-31 13:55:40 +01:00
}
2018-10-29 17:52:59 +01:00
return shader(s), nil
2014-12-31 13:55:40 +01:00
}
func (c *context) deleteShader(s shader) {
2014-12-31 13:55:40 +01:00
gl := c.gl
gl.deleteShader.Invoke(js.Value(s))
2014-12-31 13:55:40 +01:00
}
func (c *context) newProgram(shaders []shader, attributes []string) (program, error) {
2014-12-31 13:55:40 +01:00
gl := c.gl
v := gl.createProgram.Invoke()
if !v.Truthy() {
2018-10-29 17:52:59 +01:00
return program{}, errors.New("opengl: glCreateProgram failed")
2014-12-31 13:55:40 +01:00
}
for _, shader := range shaders {
gl.attachShader.Invoke(v, js.Value(shader))
2014-12-31 13:55:40 +01:00
}
for i, name := range attributes {
gl.bindAttribLocation.Invoke(v, i, name)
}
gl.linkProgram.Invoke(v)
if !gl.getProgramParameter.Invoke(v, gles.LINK_STATUS).Bool() {
info := gl.getProgramInfoLog.Invoke(v).String()
return program{}, fmt.Errorf("opengl: program error: %s", info)
2014-12-31 13:55:40 +01:00
}
id := c.lastProgramID
c.lastProgramID++
2018-10-29 17:52:59 +01:00
return program{
value: v,
id: id,
}, nil
2014-12-31 13:55:40 +01:00
}
func (c *context) useProgram(p program) {
2014-12-31 13:55:40 +01:00
gl := c.gl
gl.useProgram.Invoke(p.value)
2014-12-31 13:55:40 +01:00
}
func (c *context) deleteProgram(p program) {
gl := c.gl
if !gl.isProgram.Invoke(p.value).Bool() {
return
}
gl.deleteProgram.Invoke(p.value)
}
func (c *context) getUniformLocationImpl(p program, location string) uniformLocation {
2015-01-12 15:16:34 +01:00
gl := c.gl
return uniformLocation(gl.getUniformLocation.Invoke(p.value, location))
2015-01-12 15:16:34 +01:00
}
func (c *context) uniformInt(p program, location string, v int) bool {
2014-12-31 13:55:40 +01:00
gl := c.gl
2016-02-26 19:01:55 +01:00
l := c.locationCache.GetUniformLocation(c, p, location)
if l.equal(invalidUniform) {
return false
}
gl.uniform1i.Invoke(js.Value(l), v)
return true
2015-01-03 07:52:02 +01:00
}
func (c *context) uniformFloat(p program, location string, v float32) bool {
gl := c.gl
l := c.locationCache.GetUniformLocation(c, p, location)
if l.equal(invalidUniform) {
return false
}
gl.uniform1f.Invoke(js.Value(l), v)
return true
}
func (c *context) uniformFloats(p program, location string, v []float32, typ shaderir.Type) bool {
2015-01-03 07:52:02 +01:00
gl := c.gl
2016-02-26 19:01:55 +01:00
l := c.locationCache.GetUniformLocation(c, p, location)
if l.equal(invalidUniform) {
return false
}
base := typ.Main
if base == shaderir.Array {
base = typ.Sub[0].Main
}
arr := jsutil.TemporaryFloat32Array(len(v), v)
switch base {
case shaderir.Float:
if isWebGL2Available {
gl.uniform1fv.Invoke(js.Value(l), arr, 0, len(v))
} else {
gl.uniform1fv.Invoke(js.Value(l), arr.Call("subarray", 0, len(v)))
}
case shaderir.Vec2:
if isWebGL2Available {
gl.uniform2fv.Invoke(js.Value(l), arr, 0, len(v))
} else {
gl.uniform2fv.Invoke(js.Value(l), arr.Call("subarray", 0, len(v)))
}
case shaderir.Vec3:
if isWebGL2Available {
gl.uniform3fv.Invoke(js.Value(l), arr, 0, len(v))
} else {
gl.uniform3fv.Invoke(js.Value(l), arr.Call("subarray", 0, len(v)))
}
case shaderir.Vec4:
if isWebGL2Available {
gl.uniform4fv.Invoke(js.Value(l), arr, 0, len(v))
} else {
gl.uniform4fv.Invoke(js.Value(l), arr.Call("subarray", 0, len(v)))
}
case shaderir.Mat2:
if isWebGL2Available {
gl.uniformMatrix2fv.Invoke(js.Value(l), false, arr, 0, len(v))
} else {
gl.uniformMatrix2fv.Invoke(js.Value(l), false, arr.Call("subarray", 0, len(v)))
}
case shaderir.Mat3:
if isWebGL2Available {
gl.uniformMatrix3fv.Invoke(js.Value(l), false, arr, 0, len(v))
} else {
gl.uniformMatrix3fv.Invoke(js.Value(l), false, arr.Call("subarray", 0, len(v)))
}
case shaderir.Mat4:
if isWebGL2Available {
gl.uniformMatrix4fv.Invoke(js.Value(l), false, arr, 0, len(v))
} else {
gl.uniformMatrix4fv.Invoke(js.Value(l), false, arr.Call("subarray", 0, len(v)))
}
default:
panic(fmt.Sprintf("opengl: unexpected type: %s", typ.String()))
2014-12-31 13:55:40 +01:00
}
return true
2014-12-31 13:55:40 +01:00
}
2020-11-29 15:02:22 +01:00
func (c *context) vertexAttribPointer(index int, size int, stride int, offset int) {
2014-12-31 13:55:40 +01:00
gl := c.gl
gl.vertexAttribPointer.Invoke(index, size, gles.FLOAT, false, stride, offset)
2014-12-31 13:55:40 +01:00
}
2020-11-29 15:02:22 +01:00
func (c *context) enableVertexAttribArray(index int) {
2014-12-31 13:55:40 +01:00
gl := c.gl
gl.enableVertexAttribArray.Invoke(index)
2014-12-31 13:55:40 +01:00
}
2020-11-29 15:02:22 +01:00
func (c *context) disableVertexAttribArray(index int) {
2014-12-31 13:55:40 +01:00
gl := c.gl
gl.disableVertexAttribArray.Invoke(index)
2014-12-31 13:55:40 +01:00
}
func (c *context) newArrayBuffer(size int) buffer {
2014-12-31 13:55:40 +01:00
gl := c.gl
b := gl.createBuffer.Invoke()
gl.bindBuffer.Invoke(gles.ARRAY_BUFFER, js.Value(b))
gl.bufferData.Invoke(gles.ARRAY_BUFFER, size, gles.DYNAMIC_DRAW)
2018-10-29 17:52:59 +01:00
return buffer(b)
}
func (c *context) newElementArrayBuffer(size int) buffer {
gl := c.gl
b := gl.createBuffer.Invoke()
gl.bindBuffer.Invoke(gles.ELEMENT_ARRAY_BUFFER, js.Value(b))
gl.bufferData.Invoke(gles.ELEMENT_ARRAY_BUFFER, size, gles.DYNAMIC_DRAW)
2018-10-29 17:52:59 +01:00
return buffer(b)
2015-01-17 04:45:19 +01:00
}
2020-11-21 14:59:30 +01:00
func (c *context) bindArrayBuffer(b buffer) {
2015-01-17 04:45:19 +01:00
gl := c.gl
gl.bindBuffer.Invoke(gles.ARRAY_BUFFER, js.Value(b))
2020-11-21 14:59:30 +01:00
}
func (c *context) bindElementArrayBuffer(b buffer) {
gl := c.gl
gl.bindBuffer.Invoke(gles.ELEMENT_ARRAY_BUFFER, js.Value(b))
2014-12-31 13:55:40 +01:00
}
func (c *context) arrayBufferSubData(data []float32) {
2014-12-31 13:55:40 +01:00
gl := c.gl
l := len(data) * 4
arr := jsutil.TemporaryUint8Array(l, data)
if isWebGL2Available {
gl.bufferSubData.Invoke(gles.ARRAY_BUFFER, 0, arr, 0, l)
} else {
gl.bufferSubData.Invoke(gles.ARRAY_BUFFER, 0, arr.Call("subarray", 0, l))
}
}
func (c *context) elementArrayBufferSubData(data []uint16) {
gl := c.gl
l := len(data) * 2
arr := jsutil.TemporaryUint8Array(l, data)
if isWebGL2Available {
gl.bufferSubData.Invoke(gles.ELEMENT_ARRAY_BUFFER, 0, arr, 0, l)
} else {
gl.bufferSubData.Invoke(gles.ELEMENT_ARRAY_BUFFER, 0, arr.Call("subarray", 0, l))
}
2014-12-31 13:55:40 +01:00
}
func (c *context) deleteBuffer(b buffer) {
gl := c.gl
gl.deleteBuffer.Invoke(js.Value(b))
}
func (c *context) drawElements(len int, offsetInBytes int) {
2014-12-31 13:55:40 +01:00
gl := c.gl
gl.drawElements.Invoke(gles.TRIANGLES, len, gles.UNSIGNED_SHORT, offsetInBytes)
2014-12-31 13:55:40 +01:00
}
func (c *context) maxTextureSizeImpl() int {
gl := c.gl
return gl.getParameter.Invoke(gles.MAX_TEXTURE_SIZE).Int()
}
func (c *context) getShaderPrecisionFormatPrecision() int {
gl := c.gl
return gl.getShaderPrecisionFormat.Invoke(gles.FRAGMENT_SHADER, gles.HIGH_FLOAT).Get("precision").Int()
}
func (c *context) flush() {
gl := c.gl
gl.flush.Invoke()
}
2019-05-26 12:08:46 +02:00
func (c *context) needsRestoring() bool {
2021-01-04 18:07:30 +01:00
return needsRestoring
2019-05-26 12:08:46 +02:00
}
func (c *context) canUsePBO() bool {
return false
}
func (c *context) texSubImage2D(t textureNative, args []*driver.ReplacePixelsArgs) {
c.bindTexture(t)
gl := c.gl
for _, a := range args {
arr := jsutil.TemporaryUint8Array(len(a.Pixels), a.Pixels)
if isWebGL2Available {
// void texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
// GLsizei width, GLsizei height,
// GLenum format, GLenum type, ArrayBufferView pixels, srcOffset);
gl.texSubImage2D.Invoke(gles.TEXTURE_2D, 0, a.X, a.Y, a.Width, a.Height, gles.RGBA, gles.UNSIGNED_BYTE, arr, 0)
} else {
// void texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
// GLsizei width, GLsizei height,
// GLenum format, GLenum type, ArrayBufferView? pixels);
gl.texSubImage2D.Invoke(gles.TEXTURE_2D, 0, a.X, a.Y, a.Width, a.Height, gles.RGBA, gles.UNSIGNED_BYTE, arr)
}
}
}
func (c *context) newPixelBufferObject(width, height int) buffer {
gl := c.gl
b := gl.createBuffer.Invoke()
gl.bindBuffer.Invoke(gles.PIXEL_UNPACK_BUFFER, js.Value(b))
gl.bufferData.Invoke(gles.PIXEL_UNPACK_BUFFER, 4*width*height, gles.STREAM_DRAW)
gl.bindBuffer.Invoke(gles.PIXEL_UNPACK_BUFFER, nil)
return buffer(b)
}
func (c *context) replacePixelsWithPBO(buffer buffer, t textureNative, width, height int, args []*driver.ReplacePixelsArgs) {
if !isWebGL2Available {
panic("opengl: WebGL2 must be available when replacePixelsWithPBO is called")
}
c.bindTexture(t)
gl := c.gl
gl.bindBuffer.Invoke(gles.PIXEL_UNPACK_BUFFER, js.Value(buffer))
stride := 4 * width
for _, a := range args {
arr := jsutil.TemporaryUint8Array(len(a.Pixels), a.Pixels)
offset := 4 * (a.Y*width + a.X)
for j := 0; j < a.Height; j++ {
gl.bufferSubData.Invoke(gles.PIXEL_UNPACK_BUFFER, offset+stride*j, arr, 4*a.Width*j, 4*a.Width)
}
}
// void texSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
// GLsizei width, GLsizei height,
// GLenum format, GLenum type, GLintptr offset);
gl.texSubImage2D.Invoke(gles.TEXTURE_2D, 0, 0, 0, width, height, gles.RGBA, gles.UNSIGNED_BYTE, 0)
gl.bindBuffer.Invoke(gles.PIXEL_UNPACK_BUFFER, nil)
}
func (c *context) getBufferSubData(buffer buffer, width, height int) []byte {
if !isWebGL2Available {
panic("opengl: WebGL2 must be available when getBufferSubData is called")
}
gl := c.gl
gl.bindBuffer.Invoke(gles.PIXEL_UNPACK_BUFFER, js.Value(buffer))
l := 4 * width * height
arr := jsutil.TemporaryUint8Array(l, nil)
gl.getBufferSubData.Invoke(gles.PIXEL_UNPACK_BUFFER, 0, arr, 0, l)
gl.bindBuffer.Invoke(gles.PIXEL_UNPACK_BUFFER, nil)
return jsutil.Uint8ArrayToSlice(arr, l)
}