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| import androidx.compose.foundation.Canvas | |
| import androidx.compose.foundation.layout.fillMaxSize | |
| import androidx.compose.runtime.CompositionLocal | |
| import androidx.compose.runtime.LaunchedEffect | |
| import androidx.compose.runtime.getValue | |
| import androidx.compose.runtime.mutableStateOf | |
| import androidx.compose.runtime.remember | |
| import androidx.compose.runtime.setValue | |
| import androidx.compose.ui.Modifier | |
| import androidx.compose.ui.graphics.nativeCanvas | |
| import androidx.compose.ui.window.Window | |
| import androidx.compose.ui.window.application | |
| import kotlinx.coroutines.Dispatchers | |
| import kotlinx.coroutines.isActive | |
| import kotlinx.coroutines.withContext | |
| import loadTexture | |
| import org.jetbrains.skia.BackendTexture | |
| import org.jetbrains.skia.ColorType | |
| import org.jetbrains.skia.DirectContext | |
| import org.jetbrains.skia.Image | |
| import org.jetbrains.skia.Surface | |
| import org.jetbrains.skia.SurfaceOrigin | |
| import org.jetbrains.skiko.SkiaLayer | |
| import org.lwjgl.opengl.GL11 | |
| import org.lwjgl.opengl.GL11.GL_RGBA | |
| import org.lwjgl.opengl.GL11.GL_TEXTURE_2D | |
| import java.awt.Window | |
| import java.io.File | |
| fun main() = application { | |
| System.setProperty("skiko.renderApi", "OPENGL") | |
| var textureId: Int? = null | |
| Window( | |
| ::exitApplication, | |
| title = "OpenGl Test", | |
| ) { | |
| val window = LocalWindow.current!! | |
| var directContext by remember { mutableStateOf<DirectContext?>(null) } | |
| LaunchedEffect(window) { | |
| withContext(Dispatchers.IO) { | |
| while (isActive) { | |
| window.directContext()?.let { | |
| directContext = it | |
| return@withContext | |
| } | |
| } | |
| } | |
| } | |
| Canvas(Modifier.fillMaxSize()) { | |
| val context = directContext ?: return@Canvas | |
| if (textureId == null) { | |
| val img = "image.png" | |
| textureId = loadTexture(File(img)) | |
| } | |
| GL11.glClear(GL11.GL_COLOR_BUFFER_BIT) | |
| GL11.glEnable(GL11.GL_TEXTURE_2D) | |
| GL11.glBindTexture(GL11.GL_TEXTURE_2D, textureId) | |
| GL11.glBegin(GL11.GL_QUADS) | |
| GL11.glTexCoord2f(0f, 0f) | |
| GL11.glVertex2f(-1f, -1f) | |
| GL11.glTexCoord2f(1f, 0f) | |
| GL11.glVertex2f(1f, -1f) | |
| GL11.glTexCoord2f(1f, 1f) | |
| GL11.glVertex2f(1f, 1f) | |
| GL11.glTexCoord2f(0f, 1f) | |
| GL11.glVertex2f(-1f, 1f) | |
| GL11.glEnd() | |
| GL11.glDisable(GL11.GL_TEXTURE_2D) | |
| val backendTex = BackendTexture.makeGL( | |
| width = size.width.toInt(), | |
| height = size.height.toInt(), | |
| isMipmapped = false, | |
| textureId = textureId, | |
| textureTarget = GL_TEXTURE_2D, | |
| textureFormat = GL_RGBA | |
| ) | |
| val image = Image.adoptTextureFrom( | |
| context, | |
| backendTex, | |
| SurfaceOrigin.TOP_LEFT, | |
| ColorType.RGBA_8888, | |
| ) | |
| drawContext.canvas.nativeCanvas.drawImage(image, 0f, 0f) | |
| } | |
| } | |
| } | |
| @Suppress("UNCHECKED_CAST") | |
| val LocalWindow: CompositionLocal<Window?> by lazy { | |
| val clazz = Class.forName("androidx.compose.ui.window.LocalWindowKt") | |
| val method = clazz.getMethod("getLocalWindow") | |
| method.invoke(null) as CompositionLocal<Window?> | |
| } | |
| fun Window.directContext(): DirectContext? { | |
| fun Any.getFieldValue(fieldName: String): Any? { | |
| val field = this::class.java.getDeclaredField(fieldName) | |
| field.isAccessible = true | |
| return field.get(this) | |
| } | |
| val composePanel = this.getFieldValue("composePanel")!! | |
| val composeContainer = composePanel.getFieldValue("_composeContainer")!! | |
| val mediator = composeContainer.getFieldValue("mediator")!! | |
| val contentComponent = mediator.let { | |
| val getter = it::class.java.getMethod("getContentComponent") | |
| getter.invoke(it) as SkiaLayer | |
| } | |
| val redrawer = contentComponent.let { | |
| val getter = it::class.java.getMethod("getRedrawer${'$'}skiko") | |
| getter.invoke(it) | |
| } | |
| val contextHandler = redrawer.getFieldValue("contextHandler")!! | |
| val surface = contextHandler.let { | |
| val getter = it::class.java.superclass.superclass.getDeclaredMethod("getSurface") | |
| getter.isAccessible = true | |
| getter.invoke(it) as? Surface | |
| } | |
| return surface?.recordingContext | |
| } | |
| fun loadTexture(file: File): Int { | |
| val image = ImageIO.read(file) | |
| val width = image.width | |
| val height = image.height | |
| // Convert image to RGBA | |
| val pixels = IntArray(width * height) | |
| image.getRGB(0, 0, width, height, pixels, 0, width) | |
| val buffer = BufferUtils.createByteBuffer(width * height * 4) | |
| // OpenGL expects bottom-to-top, so flip vertically | |
| for (y in height - 1 downTo 0) { | |
| for (x in 0..<width) { | |
| val pixel = pixels[y * width + x] | |
| buffer.put(((pixel shr 16) and 0xFF).toByte()) // Red | |
| buffer.put(((pixel shr 8) and 0xFF).toByte()) // Green | |
| buffer.put((pixel and 0xFF).toByte()) // Blue | |
| buffer.put(((pixel shr 24) and 0xFF).toByte()) // Alpha | |
| } | |
| } | |
| buffer.flip() | |
| GL.createCapabilities() | |
| val textureID = GL11.glGenTextures() | |
| GL11.glBindTexture(GL11.GL_TEXTURE_2D, textureID) | |
| GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL11.GL_CLAMP) | |
| GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_T, GL11.GL_CLAMP) | |
| GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_LINEAR) | |
| GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_LINEAR) | |
| GL11.glTexImage2D( | |
| GL11.GL_TEXTURE_2D, | |
| 0, | |
| GL11.GL_RGBA8, | |
| width, | |
| height, | |
| 0, | |
| GL11.GL_RGBA, | |
| GL11.GL_UNSIGNED_BYTE, | |
| buffer | |
| ) | |
| return textureID | |
| } |
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