258 lines
8.3 KiB
Go
258 lines
8.3 KiB
Go
package backend
|
|
|
|
import (
|
|
_ "embed"
|
|
|
|
"edgaru089.ink/go/gl01/internal/igwrap"
|
|
"edgaru089.ink/go/gl01/internal/render"
|
|
"github.com/go-gl/gl/all-core/gl"
|
|
"github.com/go-gl/glfw/v3.3/glfw"
|
|
"github.com/go-gl/mathgl/mgl32"
|
|
"github.com/inkyblackness/imgui-go/v4"
|
|
)
|
|
|
|
//go:embed shader.vert
|
|
var vertex string
|
|
|
|
//go:embed shader.frag
|
|
var fragment string
|
|
|
|
var (
|
|
shader *render.Shader
|
|
texture *render.Texture
|
|
|
|
vbo, elem uint32
|
|
attribPosition, attribUV, attribColor uint32
|
|
)
|
|
|
|
func renderInit() {
|
|
// Backup GL state
|
|
var lastTexture int32
|
|
var lastArrayBuffer int32
|
|
var lastVertexArray int32
|
|
gl.GetIntegerv(gl.TEXTURE_BINDING_2D, &lastTexture)
|
|
gl.GetIntegerv(gl.ARRAY_BUFFER_BINDING, &lastArrayBuffer)
|
|
gl.GetIntegerv(gl.VERTEX_ARRAY_BINDING, &lastVertexArray)
|
|
|
|
var err error
|
|
shader, err = render.NewShader(vertex, fragment)
|
|
if err != nil {
|
|
panic("igwrap.renderInit(): " + err.Error())
|
|
}
|
|
|
|
gl.BindFragDataLocation(shader.Handle(), 0, gl.Str("outputColor\x00"))
|
|
|
|
gl.GenBuffers(1, &vbo)
|
|
gl.GenBuffers(1, &elem)
|
|
|
|
CreateFontsTexture()
|
|
shader.SetUniformTexture("tex", texture)
|
|
|
|
attribPosition = uint32(gl.GetAttribLocation(shader.Handle(), gl.Str("pos\x00")))
|
|
attribUV = uint32(gl.GetAttribLocation(shader.Handle(), gl.Str("uv\x00")))
|
|
attribColor = uint32(gl.GetAttribLocation(shader.Handle(), gl.Str("color\x00")))
|
|
|
|
// Restore modified GL state
|
|
gl.BindTexture(gl.TEXTURE_2D, uint32(lastTexture))
|
|
gl.BindBuffer(gl.ARRAY_BUFFER, uint32(lastArrayBuffer))
|
|
gl.BindVertexArray(uint32(lastVertexArray))
|
|
|
|
io.SetBackendFlags(imgui.BackendFlagsRendererHasVtxOffset)
|
|
}
|
|
|
|
func CreateFontsTexture() {
|
|
|
|
// build the texture atlas
|
|
io := imgui.CurrentIO()
|
|
image := io.Fonts().TextureDataAlpha8()
|
|
|
|
var lastTexture int32
|
|
gl.GetIntegerv(gl.TEXTURE_BINDING_2D, &lastTexture)
|
|
|
|
if texture != nil {
|
|
texture.Free()
|
|
}
|
|
texture = render.NewTexture()
|
|
tex := texture.Handle()
|
|
|
|
gl.BindTexture(gl.TEXTURE_2D, tex)
|
|
gl.TexImage2D(
|
|
gl.TEXTURE_2D,
|
|
0,
|
|
gl.RED,
|
|
int32(image.Width),
|
|
int32(image.Height),
|
|
0,
|
|
gl.RED,
|
|
gl.UNSIGNED_BYTE,
|
|
image.Pixels,
|
|
)
|
|
|
|
io.Fonts().SetTextureID(imgui.TextureID(tex))
|
|
igwrap.SetTextureFlag(tex, igwrap.TextureFlag_ImGUIFont)
|
|
|
|
gl.BindTexture(gl.TEXTURE_2D, uint32(lastTexture))
|
|
}
|
|
|
|
func Render(win *glfw.Window) {
|
|
displayWidth, displayHeight := win.GetSize()
|
|
fbWidth, fbHeight := win.GetFramebufferSize()
|
|
|
|
imgui.Render()
|
|
draw := imgui.RenderedDrawData()
|
|
|
|
draw.ScaleClipRects(imgui.Vec2{
|
|
X: float32(fbWidth) / float32(displayWidth),
|
|
Y: float32(fbHeight) / float32(displayHeight),
|
|
})
|
|
|
|
// Backup GL state
|
|
var lastActiveTexture int32
|
|
gl.GetIntegerv(gl.ACTIVE_TEXTURE, &lastActiveTexture)
|
|
gl.ActiveTexture(gl.TEXTURE0)
|
|
var lastProgram int32
|
|
gl.GetIntegerv(gl.CURRENT_PROGRAM, &lastProgram)
|
|
var lastTexture int32
|
|
gl.GetIntegerv(gl.TEXTURE_BINDING_2D, &lastTexture)
|
|
var lastSampler int32
|
|
gl.GetIntegerv(gl.SAMPLER_BINDING, &lastSampler)
|
|
var lastArrayBuffer int32
|
|
gl.GetIntegerv(gl.ARRAY_BUFFER_BINDING, &lastArrayBuffer)
|
|
var lastElementArrayBuffer int32
|
|
gl.GetIntegerv(gl.ELEMENT_ARRAY_BUFFER_BINDING, &lastElementArrayBuffer)
|
|
var lastVertexArray int32
|
|
gl.GetIntegerv(gl.VERTEX_ARRAY_BINDING, &lastVertexArray)
|
|
var lastPolygonMode [2]int32
|
|
gl.GetIntegerv(gl.POLYGON_MODE, &lastPolygonMode[0])
|
|
var lastViewport [4]int32
|
|
gl.GetIntegerv(gl.VIEWPORT, &lastViewport[0])
|
|
var lastScissorBox [4]int32
|
|
gl.GetIntegerv(gl.SCISSOR_BOX, &lastScissorBox[0])
|
|
var lastBlendSrcRgb int32
|
|
gl.GetIntegerv(gl.BLEND_SRC_RGB, &lastBlendSrcRgb)
|
|
var lastBlendDstRgb int32
|
|
gl.GetIntegerv(gl.BLEND_DST_RGB, &lastBlendDstRgb)
|
|
var lastBlendSrcAlpha int32
|
|
gl.GetIntegerv(gl.BLEND_SRC_ALPHA, &lastBlendSrcAlpha)
|
|
var lastBlendDstAlpha int32
|
|
gl.GetIntegerv(gl.BLEND_DST_ALPHA, &lastBlendDstAlpha)
|
|
var lastBlendEquationRgb int32
|
|
gl.GetIntegerv(gl.BLEND_EQUATION_RGB, &lastBlendEquationRgb)
|
|
var lastBlendEquationAlpha int32
|
|
gl.GetIntegerv(gl.BLEND_EQUATION_ALPHA, &lastBlendEquationAlpha)
|
|
lastEnableBlend := gl.IsEnabled(gl.BLEND)
|
|
lastEnableCullFace := gl.IsEnabled(gl.CULL_FACE)
|
|
lastEnableDepthTest := gl.IsEnabled(gl.DEPTH_TEST)
|
|
lastEnableScissorTest := gl.IsEnabled(gl.SCISSOR_TEST)
|
|
|
|
// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, polygon fill
|
|
gl.Enable(gl.BLEND)
|
|
gl.BlendEquation(gl.FUNC_ADD)
|
|
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
|
|
gl.Disable(gl.CULL_FACE)
|
|
gl.Disable(gl.DEPTH_TEST)
|
|
gl.Enable(gl.SCISSOR_TEST)
|
|
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
|
|
|
|
// Setup viewport, orthographic projection matrix
|
|
// Our visible imgui space lies from draw_data->DisplayPos (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right).
|
|
// DisplayMin is typically (0,0) for single viewport apps.
|
|
gl.Viewport(0, 0, int32(fbWidth), int32(fbHeight))
|
|
orthoProjection := mgl32.Mat4{
|
|
2.0 / float32(displayWidth), 0.0, 0.0, 0.0,
|
|
0.0, 2.0 / float32(-displayHeight), 0.0, 0.0,
|
|
0.0, 0.0, -1.0, 0.0,
|
|
-1.0, 1.0, 0.0, 1.0,
|
|
}
|
|
shader.BindTextures()
|
|
shader.UseProgram()
|
|
shader.SetUniformMat4("projection", orthoProjection)
|
|
gl.BindSampler(0, 0) // Rely on combined texture/sampler state.
|
|
|
|
// Recreate the VAO every time
|
|
// (This is to easily allow multiple GL contexts. VAO are not shared among GL contexts, and
|
|
// we don't track creation/deletion of windows so we don't have an obvious key to use to cache them.)
|
|
var vao uint32
|
|
gl.GenVertexArrays(1, &vao)
|
|
gl.BindVertexArray(vao)
|
|
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
|
|
gl.EnableVertexAttribArray(uint32(attribPosition))
|
|
gl.EnableVertexAttribArray(uint32(attribUV))
|
|
gl.EnableVertexAttribArray(uint32(attribColor))
|
|
vertexSize, vertexOffsetPos, vertexOffsetUv, vertexOffsetCol := imgui.VertexBufferLayout()
|
|
gl.VertexAttribPointerWithOffset(uint32(attribPosition), 2, gl.FLOAT, false, int32(vertexSize), uintptr(vertexOffsetPos))
|
|
gl.VertexAttribPointerWithOffset(uint32(attribUV), 2, gl.FLOAT, false, int32(vertexSize), uintptr(vertexOffsetUv))
|
|
gl.VertexAttribPointerWithOffset(uint32(attribColor), 4, gl.UNSIGNED_BYTE, true, int32(vertexSize), uintptr(vertexOffsetCol))
|
|
indexSize := imgui.IndexBufferLayout()
|
|
drawType := gl.UNSIGNED_SHORT
|
|
const bytesPerUint32 = 4
|
|
if indexSize == bytesPerUint32 {
|
|
drawType = gl.UNSIGNED_INT
|
|
}
|
|
|
|
// Draw
|
|
for _, list := range draw.CommandLists() {
|
|
|
|
vertexBuffer, vertexBufferSize := list.VertexBuffer()
|
|
gl.BindBuffer(gl.ARRAY_BUFFER, vbo)
|
|
gl.BufferData(gl.ARRAY_BUFFER, vertexBufferSize, vertexBuffer, gl.STREAM_DRAW)
|
|
|
|
indexBuffer, indexBufferSize := list.IndexBuffer()
|
|
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, elem)
|
|
gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, indexBufferSize, indexBuffer, gl.STREAM_DRAW)
|
|
|
|
for _, cmd := range list.Commands() {
|
|
if cmd.HasUserCallback() {
|
|
cmd.CallUserCallback(list)
|
|
} else {
|
|
shader.SetUniformInt("flags", int32(igwrap.GetTextureFlag(uint32(cmd.TextureID()))))
|
|
gl.BindTexture(gl.TEXTURE_2D, uint32(cmd.TextureID()))
|
|
clipRect := cmd.ClipRect()
|
|
gl.Scissor(int32(clipRect.X), int32(fbHeight)-int32(clipRect.W), int32(clipRect.Z-clipRect.X), int32(clipRect.W-clipRect.Y))
|
|
gl.DrawElementsBaseVertexWithOffset(
|
|
gl.TRIANGLES,
|
|
int32(cmd.ElementCount()),
|
|
uint32(drawType),
|
|
uintptr(cmd.IndexOffset()*indexSize),
|
|
int32(cmd.VertexOffset()),
|
|
)
|
|
}
|
|
}
|
|
}
|
|
gl.DeleteVertexArrays(1, &vao)
|
|
|
|
// Restore modified GL state
|
|
gl.UseProgram(uint32(lastProgram))
|
|
gl.BindTexture(gl.TEXTURE_2D, uint32(lastTexture))
|
|
gl.BindSampler(0, uint32(lastSampler))
|
|
gl.ActiveTexture(uint32(lastActiveTexture))
|
|
gl.BindVertexArray(uint32(lastVertexArray))
|
|
gl.BindBuffer(gl.ARRAY_BUFFER, uint32(lastArrayBuffer))
|
|
gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, uint32(lastElementArrayBuffer))
|
|
gl.BlendEquationSeparate(uint32(lastBlendEquationRgb), uint32(lastBlendEquationAlpha))
|
|
gl.BlendFuncSeparate(uint32(lastBlendSrcRgb), uint32(lastBlendDstRgb), uint32(lastBlendSrcAlpha), uint32(lastBlendDstAlpha))
|
|
if lastEnableBlend {
|
|
gl.Enable(gl.BLEND)
|
|
} else {
|
|
gl.Disable(gl.BLEND)
|
|
}
|
|
if lastEnableCullFace {
|
|
gl.Enable(gl.CULL_FACE)
|
|
} else {
|
|
gl.Disable(gl.CULL_FACE)
|
|
}
|
|
if lastEnableDepthTest {
|
|
gl.Enable(gl.DEPTH_TEST)
|
|
} else {
|
|
gl.Disable(gl.DEPTH_TEST)
|
|
}
|
|
if lastEnableScissorTest {
|
|
gl.Enable(gl.SCISSOR_TEST)
|
|
} else {
|
|
gl.Disable(gl.SCISSOR_TEST)
|
|
}
|
|
gl.PolygonMode(gl.FRONT_AND_BACK, uint32(lastPolygonMode[0]))
|
|
gl.Viewport(lastViewport[0], lastViewport[1], lastViewport[2], lastViewport[3])
|
|
gl.Scissor(lastScissorBox[0], lastScissorBox[1], lastScissorBox[2], lastScissorBox[3])
|
|
}
|