lazarus/platform/imgui/context.go

293 lines
9.3 KiB
Go

package imgui
// #cgo linux CFLAGS: -I./cimgui
// #cgo linux LDFLAGS: -L./cimgui -l:cimgui.a -lstdc++ -lm
// #include "native.h"
import "C"
import (
"log"
"unsafe"
"github.com/FooSoft/lazarus/math"
"github.com/go-gl/gl/v2.1/gl"
"github.com/veandco/go-sdl2/sdl"
)
const (
pointerSize = unsafe.Sizeof(C.uintptr_t(0))
drawCommandSize = unsafe.Sizeof(C.ImDrawCmd{})
indexSize = unsafe.Sizeof(C.ImDrawIdx(0))
vertexSize = unsafe.Sizeof(C.ImDrawVert{})
vertexOffsetPos = unsafe.Offsetof(C.ImDrawVert{}.pos)
vertexOffsetUv = unsafe.Offsetof(C.ImDrawVert{}.uv)
vertexOffsetCol = unsafe.Offsetof(C.ImDrawVert{}.col)
)
var keyMapping = map[int]C.int{
C.ImGuiKey_Tab: sdl.SCANCODE_TAB,
C.ImGuiKey_LeftArrow: sdl.SCANCODE_LEFT,
C.ImGuiKey_RightArrow: sdl.SCANCODE_RIGHT,
C.ImGuiKey_UpArrow: sdl.SCANCODE_UP,
C.ImGuiKey_DownArrow: sdl.SCANCODE_DOWN,
C.ImGuiKey_PageUp: sdl.SCANCODE_PAGEUP,
C.ImGuiKey_PageDown: sdl.SCANCODE_PAGEDOWN,
C.ImGuiKey_Home: sdl.SCANCODE_HOME,
C.ImGuiKey_End: sdl.SCANCODE_END,
C.ImGuiKey_Insert: sdl.SCANCODE_INSERT,
C.ImGuiKey_Delete: sdl.SCANCODE_DELETE,
C.ImGuiKey_Backspace: sdl.SCANCODE_BACKSPACE,
C.ImGuiKey_Space: sdl.SCANCODE_BACKSPACE,
C.ImGuiKey_Enter: sdl.SCANCODE_RETURN,
C.ImGuiKey_Escape: sdl.SCANCODE_ESCAPE,
C.ImGuiKey_A: sdl.SCANCODE_A,
C.ImGuiKey_C: sdl.SCANCODE_C,
C.ImGuiKey_V: sdl.SCANCODE_V,
C.ImGuiKey_X: sdl.SCANCODE_X,
C.ImGuiKey_Y: sdl.SCANCODE_Y,
C.ImGuiKey_Z: sdl.SCANCODE_Z,
}
var singleton struct {
nativeContext *C.ImGuiContext
nativeIo *C.ImGuiIO
refCount int
}
type Context struct {
buttonsDown [3]bool
lastTime uint64
fontTexture uint32
displaySize math.Vec2i
bufferSize math.Vec2i
}
func New(displaySize, bufferSize math.Vec2i) (*Context, error) {
singleton.refCount++
if singleton.refCount == 1 {
log.Println("imgui global create")
singleton.nativeContext = C.igCreateContext(nil)
singleton.nativeIo = C.igGetIO()
for imguiKey, nativeKey := range keyMapping {
singleton.nativeIo.KeyMap[imguiKey] = nativeKey
}
}
log.Println("imgui context create")
c := &Context{displaySize: displaySize, bufferSize: bufferSize}
var imageData *C.uchar
var imageWidth, imageHeight C.int
C.ImFontAtlas_GetTexDataAsRGBA32(singleton.nativeIo.Fonts, &imageData, &imageWidth, &imageHeight, nil)
var lastTexture int32
gl.GetIntegerv(gl.TEXTURE_BINDING_2D, &lastTexture)
gl.GenTextures(1, &c.fontTexture)
gl.BindTexture(gl.TEXTURE_2D, c.fontTexture)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
gl.PixelStorei(gl.UNPACK_ROW_LENGTH, 0)
gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, int32(imageWidth), int32(imageHeight), 0, gl.RGBA, gl.UNSIGNED_BYTE, unsafe.Pointer(imageData))
gl.BindTexture(gl.TEXTURE_2D, uint32(lastTexture))
return c, nil
}
func (c *Context) Destroy() error {
if c == nil || c.fontTexture == 0 {
return nil
}
log.Println("imgui context destroy")
gl.DeleteTextures(1, &c.fontTexture)
singleton.nativeIo.Fonts.TexID = C.nativeHandleCast(C.uintptr_t(c.fontTexture))
c.fontTexture = 0
singleton.refCount--
if singleton.refCount == 0 {
log.Println("imgui global destroy")
C.igDestroyContext(singleton.nativeContext)
singleton.nativeContext = nil
singleton.nativeIo = nil
}
return nil
}
func (c *Context) SetDisplaySize(displaySize math.Vec2i) {
c.displaySize = displaySize
}
func (c *Context) SetBufferSize(bufferSize math.Vec2i) {
c.bufferSize = bufferSize
}
func (c *Context) BeginFrame() {
singleton.nativeIo.Fonts.TexID = C.nativeHandleCast(C.uintptr_t(c.fontTexture))
singleton.nativeIo.DisplaySize.x = C.float(c.displaySize.X)
singleton.nativeIo.DisplaySize.y = C.float(c.displaySize.Y)
currentTime := sdl.GetPerformanceCounter()
if c.lastTime > 0 {
singleton.nativeIo.DeltaTime = C.float(float32(currentTime-c.lastTime) / float32(sdl.GetPerformanceFrequency()))
} else {
singleton.nativeIo.DeltaTime = C.float(1.0 / 60.0)
}
c.lastTime = currentTime
x, y, state := sdl.GetMouseState()
singleton.nativeIo.MousePos.x = C.float(x)
singleton.nativeIo.MousePos.y = C.float(y)
for i, button := range []uint32{sdl.BUTTON_LEFT, sdl.BUTTON_RIGHT, sdl.BUTTON_MIDDLE} {
singleton.nativeIo.MouseDown[i] = C.bool(c.buttonsDown[i] || (state&sdl.Button(button)) != 0)
c.buttonsDown[i] = false
}
C.igNewFrame()
}
func (c *Context) ProcessEvent(event sdl.Event) (bool, error) {
switch event.GetType() {
case sdl.MOUSEWHEEL:
wheelEvent := event.(*sdl.MouseWheelEvent)
if wheelEvent.X > 0 {
singleton.nativeIo.MouseDelta.x++
} else if wheelEvent.X < 0 {
singleton.nativeIo.MouseDelta.x--
}
if wheelEvent.Y > 0 {
singleton.nativeIo.MouseDelta.y++
} else if wheelEvent.Y < 0 {
singleton.nativeIo.MouseDelta.y--
}
return true, nil
case sdl.MOUSEBUTTONDOWN:
buttonEvent := event.(*sdl.MouseButtonEvent)
switch buttonEvent.Button {
case sdl.BUTTON_LEFT:
c.buttonsDown[0] = true
break
case sdl.BUTTON_RIGHT:
c.buttonsDown[1] = true
break
case sdl.BUTTON_MIDDLE:
c.buttonsDown[2] = true
break
}
return true, nil
case sdl.TEXTINPUT:
inputEvent := event.(*sdl.TextInputEvent)
C.ImGuiIO_AddInputCharactersUTF8(singleton.nativeIo, (*C.char)(unsafe.Pointer(&inputEvent.Text[0])))
return true, nil
case sdl.KEYDOWN:
keyEvent := event.(*sdl.KeyboardEvent)
singleton.nativeIo.KeysDown[keyEvent.Keysym.Scancode] = true
modState := sdl.GetModState()
singleton.nativeIo.KeyCtrl = C.bool(modState&sdl.KMOD_CTRL != 0)
singleton.nativeIo.KeyAlt = C.bool(modState&sdl.KMOD_ALT != 0)
singleton.nativeIo.KeyShift = C.bool(modState&sdl.KMOD_SHIFT != 0)
case sdl.KEYUP:
keyEvent := event.(*sdl.KeyboardEvent)
singleton.nativeIo.KeysDown[keyEvent.Keysym.Scancode] = false
modState := sdl.GetModState()
singleton.nativeIo.KeyCtrl = C.bool(modState&sdl.KMOD_CTRL != 0)
singleton.nativeIo.KeyAlt = C.bool(modState&sdl.KMOD_ALT != 0)
singleton.nativeIo.KeyShift = C.bool(modState&sdl.KMOD_SHIFT != 0)
return true, nil
}
return false, nil
}
func (c *Context) EndFrame() error {
C.igRender()
var lastTexture int32
gl.GetIntegerv(gl.TEXTURE_BINDING_2D, &lastTexture)
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])
gl.PushAttrib(gl.ENABLE_BIT | gl.COLOR_BUFFER_BIT | gl.TRANSFORM_BIT)
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
gl.Disable(gl.CULL_FACE)
gl.Disable(gl.DEPTH_TEST)
gl.Disable(gl.LIGHTING)
gl.Disable(gl.COLOR_MATERIAL)
gl.Enable(gl.SCISSOR_TEST)
gl.EnableClientState(gl.VERTEX_ARRAY)
gl.EnableClientState(gl.TEXTURE_COORD_ARRAY)
gl.EnableClientState(gl.COLOR_ARRAY)
gl.Enable(gl.TEXTURE_2D)
gl.PolygonMode(gl.FRONT_AND_BACK, gl.FILL)
gl.Viewport(0, 0, int32(c.bufferSize.X), int32(c.bufferSize.Y))
gl.MatrixMode(gl.PROJECTION)
gl.PushMatrix()
gl.LoadIdentity()
gl.Ortho(0, float64(c.displaySize.X), float64(c.displaySize.Y), 0, -1, 1)
gl.MatrixMode(gl.MODELVIEW)
gl.PushMatrix()
gl.LoadIdentity()
drawData := C.igGetDrawData()
C.ImDrawData_ScaleClipRects(
drawData,
C.ImVec2{
x: C.float(float32(c.bufferSize.X) / float32(c.displaySize.X)),
y: C.float(float32(c.bufferSize.Y) / float32(c.displaySize.Y)),
},
)
for i := C.int(0); i < drawData.CmdListsCount; i++ {
var (
commandList = *(**C.ImDrawList)(unsafe.Pointer(uintptr(unsafe.Pointer(drawData.CmdLists)) + pointerSize*uintptr(i)))
vertexBuffer = unsafe.Pointer(commandList.VtxBuffer.Data)
indexBuffer = unsafe.Pointer(commandList.IdxBuffer.Data)
elementCount = C.unsigned(0)
)
gl.VertexPointer(2, gl.FLOAT, int32(vertexSize), unsafe.Pointer(uintptr(vertexBuffer)+uintptr(vertexOffsetPos)))
gl.TexCoordPointer(2, gl.FLOAT, int32(vertexSize), unsafe.Pointer(uintptr(vertexBuffer)+uintptr(vertexOffsetUv)))
gl.ColorPointer(4, gl.UNSIGNED_BYTE, int32(vertexSize), unsafe.Pointer(uintptr(vertexBuffer)+uintptr(vertexOffsetCol)))
for j := C.int(0); j < commandList.CmdBuffer.Size; j++ {
command := (*C.ImDrawCmd)(unsafe.Pointer(uintptr(unsafe.Pointer(commandList.CmdBuffer.Data)) + drawCommandSize*uintptr(j)))
gl.Scissor(
int32(command.ClipRect.x),
int32(c.bufferSize.Y)-int32(command.ClipRect.w),
int32(command.ClipRect.z-command.ClipRect.x),
int32(command.ClipRect.w-command.ClipRect.y),
)
gl.BindTexture(gl.TEXTURE_2D, uint32(uintptr(command.TextureId)))
gl.DrawElements(
gl.TRIANGLES,
int32(command.ElemCount),
gl.UNSIGNED_SHORT,
unsafe.Pointer(uintptr(unsafe.Pointer(indexBuffer))+uintptr(elementCount)*uintptr(indexSize)),
)
elementCount += command.ElemCount
}
}
gl.DisableClientState(gl.COLOR_ARRAY)
gl.DisableClientState(gl.TEXTURE_COORD_ARRAY)
gl.DisableClientState(gl.VERTEX_ARRAY)
gl.BindTexture(gl.TEXTURE_2D, uint32(lastTexture))
gl.MatrixMode(gl.MODELVIEW)
gl.PopMatrix()
gl.MatrixMode(gl.PROJECTION)
gl.PopMatrix()
gl.PopAttrib()
gl.PolygonMode(gl.FRONT, uint32(lastPolygonMode[0]))
gl.PolygonMode(gl.BACK, uint32(lastPolygonMode[1]))
gl.Viewport(lastViewport[0], lastViewport[1], lastViewport[2], lastViewport[3])
gl.Scissor(lastScissorBox[0], lastScissorBox[1], lastScissorBox[2], lastScissorBox[3])
return nil
}