func LoadTexture(name string) (tex gl.Texture, err error) {
imgFile, err := asset.Open(name)
if err != nil {
return
}
img, _, err := image.Decode(imgFile)
if err != nil {
return
}
rgba := image.NewRGBA(img.Bounds())
image_draw.Draw(rgba, rgba.Bounds(), img, image.Point{0, 0}, image_draw.Src)
tex = gl.CreateTexture()
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, tex)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
gl.TexImage2D(
gl.TEXTURE_2D,
0,
rgba.Rect.Size().X,
rgba.Rect.Size().Y,
gl.RGBA,
gl.UNSIGNED_BYTE,
rgba.Pix)
return
}
func (video *Video) drawFrame() {
gl.Clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT)
gl.UseProgram(video.prog)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, video.texture)
log.Print("Reading")
frame := <-video.pixelBuffer
buf := make([]float32, len(frame))
log.Print("Read frame")
for k, v := range frame {
buf[k] = float32(v)
}
log.Print("Writing")
if video.pixelBuffer != nil {
gl.TexImage2D(gl.TEXTURE_2D, 0, 256, 256, gl.RGBA,
gl.UNSIGNED_SHORT_4_4_4_4, f32.Bytes(binary.LittleEndian, buf...))
}
log.Print("Wrote")
gl.DrawArrays(gl.TRIANGLES, 0, 6)
video.fpsmanager.FramerateDelay()
}
// NewImage creates an Image of the given size.
//
// Both a host-memory *image.RGBA and a GL texture are created.
func NewImage(w, h int) *Image {
dx := roundToPower2(w)
dy := roundToPower2(h)
// TODO(crawshaw): Using VertexAttribPointer we can pass texture
// data with a stride, which would let us use the exact number of
// pixels on the host instead of the rounded up power 2 size.
m := image.NewRGBA(image.Rect(0, 0, dx, dy))
glimage.Do(glInit)
img := &Image{
RGBA: m.SubImage(image.Rect(0, 0, w, h)).(*image.RGBA),
Texture: gl.GenTexture(),
texWidth: dx,
texHeight: dy,
}
// TODO(crawshaw): We don't have the context on a finalizer. Find a way.
// runtime.SetFinalizer(img, func(img *Image) { gl.DeleteTexture(img.Texture) })
gl.BindTexture(gl.TEXTURE_2D, img.Texture)
gl.TexImage2D(gl.TEXTURE_2D, 0, dx, dy, gl.RGBA, gl.UNSIGNED_BYTE, nil)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
return img
}
func (w *windowImpl) Draw(src2dst f64.Aff3, src screen.Texture, sr image.Rectangle, op draw.Op, opts *screen.DrawOptions) {
t := src.(*textureImpl)
a := w.vertexAff3(sr)
gl.UseProgram(w.s.texture.program)
writeAff3(w.s.texture.mvp, mul(a, src2dst))
// OpenGL's fragment shaders' UV coordinates run from (0,0)-(1,1),
// unlike vertex shaders' XY coordinates running from (-1,+1)-(+1,-1).
//
// We are drawing a rectangle PQRS, defined by two of its
// corners, onto the entire texture. The two quads may actually
// be equal, but in the general case, PQRS can be smaller.
//
// (0,0) +---------------+ (1,0)
// | P +-----+ Q |
// | | | |
// | S +-----+ R |
// (0,1) +---------------+ (1,1)
//
// The PQRS quad is always axis-aligned. First of all, convert
// from pixel space to texture space.
tw := float64(t.size.X)
th := float64(t.size.Y)
px := float64(sr.Min.X-0) / tw
py := float64(sr.Min.Y-0) / th
qx := float64(sr.Max.X-0) / tw
sy := float64(sr.Max.Y-0) / th
// Due to axis alignment, qy = py and sx = px.
//
// The simultaneous equations are:
// 0 + 0 + a02 = px
// 0 + 0 + a12 = py
// a00 + 0 + a02 = qx
// a10 + 0 + a12 = qy = py
// 0 + a01 + a02 = sx = px
// 0 + a11 + a12 = sy
writeAff3(w.s.texture.uvp, f64.Aff3{
qx - px, 0, px,
0, sy - py, py,
})
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, t.id)
gl.Uniform1i(w.s.texture.sample, 0)
gl.BindBuffer(gl.ARRAY_BUFFER, w.s.texture.quadXY)
gl.EnableVertexAttribArray(w.s.texture.pos)
gl.VertexAttribPointer(w.s.texture.pos, 2, gl.FLOAT, false, 0, 0)
gl.BindBuffer(gl.ARRAY_BUFFER, w.s.texture.quadUV)
gl.EnableVertexAttribArray(w.s.texture.inUV)
gl.VertexAttribPointer(w.s.texture.inUV, 2, gl.FLOAT, false, 0, 0)
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
gl.DisableVertexAttribArray(w.s.texture.pos)
gl.DisableVertexAttribArray(w.s.texture.inUV)
}
func (t *textureImpl) Upload(dp image.Point, src screen.Buffer, sr image.Rectangle, sender screen.Sender) {
// TODO: adjust if dp is outside dst bounds, or sr is outside src bounds.
gl.BindTexture(gl.TEXTURE_2D, t.id)
m := src.RGBA().SubImage(sr).(*image.RGBA)
b := m.Bounds()
// TODO check m bounds smaller than t.size
gl.TexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, b.Dx(), b.Dy(), gl.RGBA, gl.UNSIGNED_BYTE, m.Pix)
// TODO: send a screen.UploadedEvent.
}
func (e *Engine) Draw(c size.Event) {
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(0.2, 0.2, 0.2, 1)
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.Clear(gl.DEPTH_BUFFER_BIT)
gl.UseProgram(e.shader.program)
m := mgl32.Perspective(0.785, float32(c.WidthPt/c.HeightPt), 0.1, 10.0)
gl.UniformMatrix4fv(e.shader.projection, m[:])
eye := mgl32.Vec3{0, 0, 8}
center := mgl32.Vec3{0, 0, 0}
up := mgl32.Vec3{0, 1, 0}
m = mgl32.LookAtV(eye, center, up)
gl.UniformMatrix4fv(e.shader.view, m[:])
m = mgl32.HomogRotate3D(float32(e.touchLoc.X/c.WidthPt-0.5)*3.14*2, mgl32.Vec3{0, 1, 0})
gl.UniformMatrix4fv(e.shader.modelx, m[:])
m = mgl32.HomogRotate3D(float32(e.touchLoc.Y/c.HeightPt-0.5)*3.14, mgl32.Vec3{1, 0, 0})
gl.UniformMatrix4fv(e.shader.modely, m[:])
coordsPerVertex := 3
for _, obj := range e.shape.Objs {
gl.BindBuffer(gl.ARRAY_BUFFER, obj.coord)
gl.EnableVertexAttribArray(e.shader.vertCoord)
gl.VertexAttribPointer(e.shader.vertCoord, coordsPerVertex, gl.FLOAT, false, 12, 0)
if obj.useuv == true {
gl.Uniform1i(e.shader.useuv, 1)
texCoordsPerVertex := 2
gl.BindBuffer(gl.ARRAY_BUFFER, obj.uvcoord)
gl.EnableVertexAttribArray(e.shader.vertTexCoord)
gl.VertexAttribPointer(e.shader.vertTexCoord, texCoordsPerVertex, gl.FLOAT, false, 8, 0)
gl.BindTexture(gl.TEXTURE_2D, obj.tex)
} else {
gl.Uniform1i(e.shader.useuv, 0)
gl.Uniform4f(e.shader.color, obj.color[0], obj.color[1], obj.color[2], obj.color[3])
}
gl.DrawArrays(gl.TRIANGLES, 0, obj.vcount)
if obj.useuv {
gl.DisableVertexAttribArray(e.shader.vertTexCoord)
}
gl.DisableVertexAttribArray(e.shader.vertCoord)
}
debug.DrawFPS(c)
}
func (e *Engine) Draw(c size.Event) {
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(0.5, 0.8, 0.8, 1)
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.Clear(gl.DEPTH_BUFFER_BIT)
gl.UseProgram(e.shader.program)
gl.Uniform3fv(e.shader.lightdir, []float32{0.5, 0.6, 0.7})
m := mgl32.Perspective(1.3, float32(c.WidthPt/c.HeightPt), 0.1, 10.0)
gl.UniformMatrix4fv(e.shader.projectionmatrix, m[:])
eye := mgl32.Vec3{0, 0, 0.2}
center := mgl32.Vec3{0, 0, 0}
up := mgl32.Vec3{0, 1, 0}
m = mgl32.LookAtV(eye, center, up)
gl.UniformMatrix4fv(e.shader.viewmatrix, m[:])
m = mgl32.HomogRotate3D((e.touchx/float32(c.WidthPt)-0.5)*6.28, mgl32.Vec3{0, 1, 0})
gl.UniformMatrix4fv(e.shader.modelmatrix, m[:])
m = mgl32.HomogRotate3D((e.touchx/float32(c.WidthPt)-0.5)*6.28, mgl32.Vec3{0, -1, 0})
gl.UniformMatrix4fv(e.shader.lightmatrix, m[:])
coordsPerVertex := 3
for _, obj := range e.shape.Objs {
gl.BindBuffer(gl.ARRAY_BUFFER, obj.coord)
gl.EnableVertexAttribArray(e.shader.vertCoord)
gl.VertexAttribPointer(e.shader.vertCoord, coordsPerVertex, gl.FLOAT, false, 12, 0)
texCoordsPerVertex := 2
gl.BindBuffer(gl.ARRAY_BUFFER, obj.uvcoord)
gl.EnableVertexAttribArray(e.shader.texcoord)
gl.VertexAttribPointer(e.shader.texcoord, texCoordsPerVertex, gl.FLOAT, false, 8, 0)
gl.BindBuffer(gl.ARRAY_BUFFER, obj.normal)
gl.EnableVertexAttribArray(e.shader.normal)
gl.VertexAttribPointer(e.shader.normal, 3, gl.FLOAT, false, 12, 0)
gl.BindTexture(gl.TEXTURE_2D, obj.tex)
gl.DrawArrays(gl.TRIANGLES, 0, obj.vcount)
gl.DisableVertexAttribArray(e.shader.texcoord)
gl.DisableVertexAttribArray(e.shader.normal)
gl.DisableVertexAttribArray(e.shader.vertCoord)
}
debug.DrawFPS(c)
}
func onPaint(sz size.Event) {
gl.ClearColor(rgb(156), rgb(39), rgb(176), 1)
gl.Clear(gl.COLOR_BUFFER_BIT)
var rotationMatrix = []float32{
f32.Cos(-alpha), -f32.Sin(-alpha), 0.0,
f32.Sin(-alpha), f32.Cos(-alpha), 0.0,
0.0, 0.0, 1.0,
}
gl.UseProgram(program)
// setting color
gl.Uniform4f(color, rgb(255), rgb(255), rgb(255), 1)
gl.UniformMatrix3fv(matrixId, rotationMatrix)
gl.Uniform1f(resolutionId, resIndex)
gl.BindBuffer(gl.ARRAY_BUFFER, swasBuffer)
gl.EnableVertexAttribArray(position)
gl.VertexAttribPointer(position, 3, gl.FLOAT, false, 0, 0)
gl.DrawArrays(gl.LINES, 0, 16)
gl.DisableVertexAttribArray(position)
gl.UseProgram(texProgram)
// setting color
gl.Uniform4f(color2, rgb(130), rgb(50), rgb(80), 1)
gl.Uniform1f(resolutionId2, resIndex)
gl.UniformMatrix3fv(matrixId2, rotationMatrix)
gl.BindBuffer(gl.ARRAY_BUFFER, quadBuffer)
gl.EnableVertexAttribArray(position2)
gl.VertexAttribPointer(position2, 3, gl.FLOAT, false, 0, 0)
gl.BindBuffer(gl.ARRAY_BUFFER, quadTexBuffer)
gl.EnableVertexAttribArray(textureCoords)
gl.VertexAttribPointer(textureCoords, 2, gl.FLOAT, false, 0, 0)
gl.Uniform1i(gl.GetUniformLocation(texProgram, "myTexture"), 0)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, textureId)
gl.DrawArrays(gl.TRIANGLES, 0, 6)
gl.DisableVertexAttribArray(position2)
gl.DisableVertexAttribArray(textureCoords)
if spin == true {
alpha += 0.1
}
if alpha >= 360 {
alpha = 0.0
}
}
func (video *Video) initGL() {
log.Print("Initing")
video.fpsmanager = gfx.NewFramerate()
video.fpsmanager.SetFramerate(60)
gl.ClearColor(0.0, 0.0, 0.0, 1.0)
gl.Enable(gl.CULL_FACE)
gl.Enable(gl.DEPTH_TEST)
log.Print("Creating program")
video.prog = createProgram(vertShaderSrcDef, fragShaderSrcDef)
log.Print("Attrib loc 1")
posAttrib := attribLocation(video.prog, "vPosition")
log.Print("Attrib loc 2")
texCoordAttr := attribLocation(video.prog, "vTexCoord")
log.Print("Uniform loc 1")
paletteLoc := uniformLocation(video.prog, "palette")
log.Print("Uniform loc 2")
video.textureUni = uniformLocation(video.prog, "texture")
log.Print("Gen Texture")
video.texture = genTexture()
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, video.texture)
log.Print("TexParam")
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST)
gl.UseProgram(video.prog)
gl.EnableVertexAttribArray(posAttrib)
gl.EnableVertexAttribArray(texCoordAttr)
gl.Uniform3iv(paletteLoc, nes.SPaletteRgb)
log.Print("VertBO")
vertVBO := genBuffer()
checkGLError()
gl.BindBuffer(gl.ARRAY_BUFFER, vertVBO)
verts := f32.Bytes(binary.LittleEndian, -1.0, 1.0, -1.0, -1.0, 1.0, -1.0, 1.0, -1.0, 1.0, 1.0, -1.0, 1.0)
gl.BufferData(gl.ARRAY_BUFFER, verts, gl.STATIC_DRAW)
textCoorBuf := genBuffer()
checkGLError()
gl.BindBuffer(gl.ARRAY_BUFFER, textCoorBuf)
texVerts := f32.Bytes(binary.LittleEndian, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0)
gl.BufferData(gl.ARRAY_BUFFER, texVerts, gl.STATIC_DRAW)
gl.VertexAttribPointer(posAttrib, 2, gl.FLOAT, false, 0, 0)
gl.VertexAttribPointer(texCoordAttr, 2, gl.FLOAT, false, 0, 0)
log.Print("Started")
}
func (e *Engine) Draw(c size.Event) {
since := time.Now().Sub(e.started)
//gl.Enable()
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(0, 0, 0, 1)
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.Clear(gl.DEPTH_BUFFER_BIT)
gl.UseProgram(e.shader.program)
m := mgl32.Perspective(0.785, float32(c.WidthPt/c.HeightPt), 0.1, 10.0)
gl.UniformMatrix4fv(e.shader.projection, m[:])
eye := mgl32.Vec3{3, 3, 3}
center := mgl32.Vec3{0, 0, 0}
up := mgl32.Vec3{0, 1, 0}
m = mgl32.LookAtV(eye, center, up)
gl.UniformMatrix4fv(e.shader.view, m[:])
m = mgl32.HomogRotate3D(float32(since.Seconds()), mgl32.Vec3{0, 1, 0})
gl.UniformMatrix4fv(e.shader.model, m[:])
gl.BindBuffer(gl.ARRAY_BUFFER, e.shape.buf)
coordsPerVertex := 3
texCoordsPerVertex := 2
vertexCount := len(cubeData) / (coordsPerVertex + texCoordsPerVertex)
gl.EnableVertexAttribArray(e.shader.vertCoord)
gl.VertexAttribPointer(e.shader.vertCoord, coordsPerVertex, gl.FLOAT, false, 20, 0) // 4 bytes in float, 5 values per vertex
gl.EnableVertexAttribArray(e.shader.vertTexCoord)
gl.VertexAttribPointer(e.shader.vertTexCoord, texCoordsPerVertex, gl.FLOAT, false, 20, 12)
gl.BindTexture(gl.TEXTURE_2D, e.shape.texture)
gl.DrawArrays(gl.TRIANGLES, 0, vertexCount)
gl.DisableVertexAttribArray(e.shader.vertCoord)
debug.DrawFPS(c)
}
func (e *Engine) Draw(c event.Config) {
since := time.Now().Sub(e.started)
gl.Enable(gl.DEPTH_TEST)
gl.DepthFunc(gl.LESS)
gl.ClearColor(0, 0, 0, 1)
gl.Clear(gl.COLOR_BUFFER_BIT)
gl.Clear(gl.DEPTH_BUFFER_BIT)
gl.UseProgram(e.shader.program)
// Setup MVP
var m mgl.Mat4
m = mgl.Perspective(0.785, float32(c.Width/c.Height), 0.1, 10.0)
gl.UniformMatrix4fv(e.shader.projection, m[:])
m = mgl.LookAtV(
mgl.Vec3{3, 3, 3}, // eye
mgl.Vec3{0, 0, 0}, // center
mgl.Vec3{0, 1, 0}, // up
)
gl.UniformMatrix4fv(e.shader.view, m[:])
m = mgl.HomogRotate3D(float32(since.Seconds()), mgl.Vec3{0, 1, 0})
gl.UniformMatrix4fv(e.shader.model, m[:])
// Draw our shape
gl.BindBuffer(gl.ARRAY_BUFFER, e.shape.buf)
gl.EnableVertexAttribArray(e.shader.vertCoord)
gl.VertexAttribPointer(e.shader.vertCoord, e.shape.coordsPerVertex, gl.FLOAT, false, 20, 0) // 4 bytes in float, 5 values per vertex
gl.EnableVertexAttribArray(e.shader.vertTexCoord)
gl.VertexAttribPointer(e.shader.vertTexCoord, e.shape.texCoordsPerVertex, gl.FLOAT, false, 20, 12)
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, e.shape.texture)
gl.DrawArrays(gl.TRIANGLES, 0, e.shape.vertexCount)
gl.DisableVertexAttribArray(e.shader.vertCoord)
//debug.DrawFPS(c)
}
func onStart() {
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
texture := loadImages("495.png")
textureId = gl.CreateTexture()
gl.BindTexture(gl.TEXTURE_2D, textureId)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.REPEAT)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.REPEAT)
gl.TexImage2D(gl.TEXTURE_2D, 0, texture.Rect.Size().X, texture.Rect.Size().Y, gl.RGBA, gl.UNSIGNED_BYTE, texture.Pix)
// loading Shaders & linking programs
program = createProgram("vShader.vs", "fShader.vs")
texProgram = createProgram("vTexShader.vs", "fTexShader.vs")
quadBuffer = gl.CreateBuffer()
gl.BindBuffer(gl.ARRAY_BUFFER, quadBuffer)
gl.BufferData(gl.ARRAY_BUFFER, quadData, gl.STATIC_DRAW)
quadTexBuffer = gl.CreateBuffer()
gl.BindBuffer(gl.ARRAY_BUFFER, quadTexBuffer)
gl.BufferData(gl.ARRAY_BUFFER, quadTexData, gl.STATIC_DRAW)
swasBuffer = gl.CreateBuffer()
gl.BindBuffer(gl.ARRAY_BUFFER, swasBuffer)
gl.BufferData(gl.ARRAY_BUFFER, swastikaData, gl.STATIC_DRAW)
position = gl.GetAttribLocation(program, "position")
color = gl.GetUniformLocation(program, "color")
matrixId = gl.GetUniformLocation(program, "rotationMatrix")
resolutionId = gl.GetUniformLocation(program, "resIndex")
position2 = gl.GetAttribLocation(texProgram, "position")
textureCoords = gl.GetAttribLocation(texProgram, "texCoords")
matrixId2 = gl.GetUniformLocation(texProgram, "rotationMatrix")
resolutionId2 = gl.GetUniformLocation(texProgram, "resIndex")
color2 = gl.GetUniformLocation(texProgram, "color")
}
// init creates an underlying GL texture for a key.
// Must be called with a valid GL context.
// Must hold tm.Mutex before calling.
func (tm *texmapCache) init(key texmapKey) {
tex := tm.texs[key]
if tex.gltex.Value != 0 {
panic(fmt.Sprintf("attempting to init key (%v) with valid texture", key))
}
tex.gltex = gl.CreateTexture()
gl.BindTexture(gl.TEXTURE_2D, tex.gltex)
gl.TexImage2D(gl.TEXTURE_2D, 0, tex.width, tex.height, gl.RGBA, gl.UNSIGNED_BYTE, nil)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
for _, t := range tm.toDelete {
gl.DeleteTexture(t)
}
tm.toDelete = nil
}
func (s *screenImpl) NewTexture(size image.Point) (screen.Texture, error) {
s.mu.Lock()
defer s.mu.Unlock()
if !gl.IsProgram(s.texture.program) {
p, err := compileProgram(textureVertexSrc, textureFragmentSrc)
if err != nil {
return nil, err
}
s.texture.program = p
s.texture.pos = gl.GetAttribLocation(p, "pos")
s.texture.mvp = gl.GetUniformLocation(p, "mvp")
s.texture.uvp = gl.GetUniformLocation(p, "uvp")
s.texture.inUV = gl.GetAttribLocation(p, "inUV")
s.texture.sample = gl.GetUniformLocation(p, "sample")
s.texture.quadXY = gl.CreateBuffer()
s.texture.quadUV = gl.CreateBuffer()
gl.BindBuffer(gl.ARRAY_BUFFER, s.texture.quadXY)
gl.BufferData(gl.ARRAY_BUFFER, quadXYCoords, gl.STATIC_DRAW)
gl.BindBuffer(gl.ARRAY_BUFFER, s.texture.quadUV)
gl.BufferData(gl.ARRAY_BUFFER, quadUVCoords, gl.STATIC_DRAW)
}
t := &textureImpl{
id: gl.CreateTexture(),
size: size,
}
gl.BindTexture(gl.TEXTURE_2D, t.id)
gl.TexImage2D(gl.TEXTURE_2D, 0, size.X, size.Y, gl.RGBA, gl.UNSIGNED_BYTE, nil)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE)
return t, nil
}
func (shape *Skybox) Draw(camera Camera) {
shader := shape.shader
gl.DepthFunc(gl.LEQUAL)
gl.DepthMask(false)
projection, view := camera.Projection(), camera.View().Mat3().Mat4()
gl.UniformMatrix4fv(shader.Uniform("projection"), projection[:])
gl.UniformMatrix4fv(shader.Uniform("view"), view[:])
gl.BindTexture(gl.TEXTURE_CUBE_MAP, shape.Texture)
gl.BindBuffer(gl.ARRAY_BUFFER, shape.VBO)
gl.EnableVertexAttribArray(shader.Attrib("vertCoord"))
gl.VertexAttribPointer(shader.Attrib("vertCoord"), vertexDim, gl.FLOAT, false, shape.Stride(), 0)
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, shape.IBO)
gl.DrawElements(gl.TRIANGLES, len(shape.indices), gl.UNSIGNED_BYTE, 0)
gl.DisableVertexAttribArray(shader.Attrib("vertCoord"))
gl.DepthMask(true)
gl.DepthFunc(gl.LESS)
}
// Draw draws the srcBounds part of the image onto a parallelogram, defined by
// three of its corners, in the current GL framebuffer.
func (img *Image) Draw(topLeft, topRight, bottomLeft geom.Point, srcBounds image.Rectangle) {
// TODO(crawshaw): Adjust viewport for the top bar on android?
gl.UseProgram(glimage.program)
{
// We are drawing a parallelogram PQRS, defined by three of its
// corners, onto the entire GL framebuffer ABCD. The two quads may
// actually be equal, but in the general case, PQRS can be smaller,
// and PQRS is not necessarily axis-aligned.
//
// A +---------------+ B
// | P +-----+ Q |
// | | | |
// | S +-----+ R |
// D +---------------+ C
//
// There are two co-ordinate spaces: geom space and framebuffer space.
// In geom space, the ABCD rectangle is:
//
// (0, 0) (geom.Width, 0)
// (0, geom.Height) (geom.Width, geom.Height)
//
// and the PQRS quad is:
//
// (topLeft.X, topLeft.Y) (topRight.X, topRight.Y)
// (bottomLeft.X, bottomLeft.Y) (implicit, implicit)
//
// In framebuffer space, the ABCD rectangle is:
//
// (-1, +1) (+1, +1)
// (-1, -1) (+1, -1)
//
// First of all, convert from geom space to framebuffer space. For
// later convenience, we divide everything by 2 here: px2 is half of
// the P.X co-ordinate (in framebuffer space).
px2 := -0.5 + float32(topLeft.X/geom.Width)
py2 := +0.5 - float32(topLeft.Y/geom.Height)
qx2 := -0.5 + float32(topRight.X/geom.Width)
qy2 := +0.5 - float32(topRight.Y/geom.Height)
sx2 := -0.5 + float32(bottomLeft.X/geom.Width)
sy2 := +0.5 - float32(bottomLeft.Y/geom.Height)
// Next, solve for the affine transformation matrix
// [ a00 a01 a02 ]
// a = [ a10 a11 a12 ]
// [ 0 0 1 ]
// that maps A to P:
// a × [ -1 +1 1 ]' = [ 2*px2 2*py2 1 ]'
// and likewise maps B to Q and D to S. Solving those three constraints
// implies that C maps to R, since affine transformations keep parallel
// lines parallel. This gives 6 equations in 6 unknowns:
// -a00 + a01 + a02 = 2*px2
// -a10 + a11 + a12 = 2*py2
// +a00 + a01 + a02 = 2*qx2
// +a10 + a11 + a12 = 2*qy2
// -a00 - a01 + a02 = 2*sx2
// -a10 - a11 + a12 = 2*sy2
// which gives:
// a00 = (2*qx2 - 2*px2) / 2 = qx2 - px2
// and similarly for the other elements of a.
glimage.mvp.WriteAffine(&f32.Affine{{
qx2 - px2,
px2 - sx2,
qx2 + sx2,
}, {
qy2 - py2,
py2 - sy2,
qy2 + sy2,
}})
}
{
// Mapping texture co-ordinates is similar, except that in texture
// space, the ABCD rectangle is:
//
// (0,0) (1,0)
// (0,1) (1,1)
//
// and the PQRS quad is always axis-aligned. First of all, convert
// from pixel space to texture space.
w := float32(img.texWidth)
h := float32(img.texHeight)
px := float32(srcBounds.Min.X-img.Rect.Min.X) / w
py := float32(srcBounds.Min.Y-img.Rect.Min.Y) / h
qx := float32(srcBounds.Max.X-img.Rect.Min.X) / w
sy := float32(srcBounds.Max.Y-img.Rect.Min.Y) / h
// Due to axis alignment, qy = py and sx = px.
//
// The simultaneous equations are:
// 0 + 0 + a02 = px
// 0 + 0 + a12 = py
// a00 + 0 + a02 = qx
// a10 + 0 + a12 = qy = py
// 0 + a01 + a02 = sx = px
// 0 + a11 + a12 = sy
glimage.uvp.WriteAffine(&f32.Affine{{
qx - px,
0,
px,
}, {
0,
sy - py,
py,
}})
}
gl.ActiveTexture(gl.TEXTURE0)
gl.BindTexture(gl.TEXTURE_2D, img.Texture)
gl.Uniform1i(glimage.textureSample, 0)
gl.BindBuffer(gl.ARRAY_BUFFER, glimage.quadXY)
gl.EnableVertexAttribArray(glimage.pos)
gl.VertexAttribPointer(glimage.pos, 2, gl.FLOAT, false, 0, 0)
gl.BindBuffer(gl.ARRAY_BUFFER, glimage.quadUV)
gl.EnableVertexAttribArray(glimage.inUV)
gl.VertexAttribPointer(glimage.inUV, 2, gl.FLOAT, false, 0, 0)
gl.DrawArrays(gl.TRIANGLE_STRIP, 0, 4)
gl.DisableVertexAttribArray(glimage.pos)
gl.DisableVertexAttribArray(glimage.inUV)
}
// Upload copies the host image data to the GL device.
func (img *Image) Upload() {
gl.BindTexture(gl.TEXTURE_2D, img.Texture)
gl.TexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, img.texWidth, img.texHeight, gl.RGBA, gl.UNSIGNED_BYTE, img.Pix)
}
// Upload copies the host image data to the GL device.
func (img *Image) Upload() {
tex := texmap.get(*img.key)
gl.BindTexture(gl.TEXTURE_2D, tex.gltex)
gl.TexSubImage2D(gl.TEXTURE_2D, 0, 0, 0, tex.width, tex.height, gl.RGBA, gl.UNSIGNED_BYTE, img.RGBA.Pix)
}
