[v4,03/23] libcamera: software_isp: egl: Add a eGL base helper class
diff mbox series

Message ID 20251120233347.5046-4-bryan.odonoghue@linaro.org
State New
Headers show
Series
  • Add GLES 2.0 GPUISP to libcamera
Related show

Commit Message

Bryan O'Donoghue Nov. 20, 2025, 11:33 p.m. UTC
Introduce an eGL base helper class which provides an eGL context based on a
passed width and height.

The initGLContext function could be overloaded to provide an interface to a
real display.

A set of helper functions is provided to compile and link GLSL shaders.
linkShaderProgram currently compiles vertex/fragment pairs but could be
overloaded or passed a parameter to link a compute shader instead.

Breaking the eGL interface away from debayering - allows to use the eGL
context inside of a dma-buf heap cleanly, reuse that context inside of a
debayer layer and conceivably reuse the context in a multi-stage shader
pass.

Small note the image_attrs[] array doesn't pass checkstyle.py however the
elements of the array are in pairs.

Acked-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
---
 include/libcamera/internal/egl.h | 412 +++++++++++++++++++++++++++++
 src/libcamera/egl.cpp            | 436 +++++++++++++++++++++++++++++++
 src/libcamera/meson.build        |  23 ++
 3 files changed, 871 insertions(+)
 create mode 100644 include/libcamera/internal/egl.h
 create mode 100644 src/libcamera/egl.cpp

Patch
diff mbox series

diff --git a/include/libcamera/internal/egl.h b/include/libcamera/internal/egl.h
new file mode 100644
index 000000000..e61a394af
--- /dev/null
+++ b/include/libcamera/internal/egl.h
@@ -0,0 +1,412 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Linaro Ltd.
+ *
+ * Authors:
+ * Bryan O'Donoghue <bryan.odonoghue@linaro.org>
+ *
+ * egl_context.cpp - Helper class for managing eGL interactions.
+ */
+
+#pragma once
+
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <libcamera/base/log.h>
+
+#include "libcamera/base/utils.h"
+#include "libcamera/internal/gbm.h"
+
+#define EGL_EGLEXT_PROTOTYPES
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+#define GL_GLEXT_PROTOTYPES
+#include <GLES2/gl2.h>
+#include <GLES2/gl2ext.h>
+
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(eGL)
+
+/**
+ * \class eGLImage
+ * \brief Helper class for managing EGL image resources
+ *
+ * The eGLImage class encapsulates OpenGL ES texture and framebuffer objects
+ * along with their associated EGL image. It aggregates handles, descriptors,
+ * and routines for managing textures that can be associated with shader
+ * uniform IDs.
+ *
+ * This class is particularly useful for managing DMA-BUF backed textures
+ * in zero-copy rendering pipelines, where textures are bound to specific
+ * texture units and can be used as both input textures and render targets.
+ */
+class eGLImage
+{
+public:
+	/**
+	 * \brief Construct an eGLImage with explicit stride
+	 * \param[in] width Image width in pixels
+	 * \param[in] height Image height in pixels
+	 * \param[in] bpp Bytes per pixel
+	 * \param[in] stride Row stride in bytes
+	 * \param[in] texture_unit OpenGL texture unit (e.g., GL_TEXTURE0)
+	 * \param[in] texture_unit_uniform_id Shader uniform ID for this texture unit
+	 *
+	 * Creates an eGLImage with the specified dimensions and stride. The stride
+	 * may differ from width * bpp due to alignment.
+	 */
+	eGLImage(uint32_t width, uint32_t height, uint32_t bpp, uint32_t stride, GLenum texture_unit, uint32_t texture_unit_uniform_id)
+	{
+		init(width, height, bpp, stride, texture_unit, texture_unit_uniform_id);
+	}
+
+	/**
+	 * \brief Construct an eGLImage with automatic stride calculation
+	 * \param[in] width Image width in pixels
+	 * \param[in] height Image height in pixels
+	 * \param[in] bpp Bytes per pixel
+	 * \param[in] texture_unit OpenGL texture unit (e.g., GL_TEXTURE0)
+	 * \param[in] texture_unit_uniform_id Shader uniform ID for this texture unit
+	 *
+	 * Creates an eGLImage with automatic stride calculation. The stride is
+	 * aligned to 256 bytes because 256 byte alignment is a common baseline alignment for GPUs.
+	 */
+	eGLImage(uint32_t width, uint32_t height, uint32_t bpp, GLenum texture_unit, uint32_t texture_unit_uniform_id)
+	{
+		uint32_t stride = libcamera::utils::alignUp(width * bpp, 256);
+
+		init(width, height, bpp, stride, texture_unit, texture_unit_uniform_id);
+	}
+
+	/**
+	 * \brief Destroy the eGLImage
+	 *
+	 * Cleans up OpenGL resources by deleting the framebuffer object and
+	 * texture.
+	 */
+	~eGLImage()
+	{
+		glDeleteFramebuffers(1, &fbo_);
+		glDeleteTextures(1, &texture_);
+	}
+
+	uint32_t width_;			/**< Image width in pixels */
+	uint32_t height_;			/**< Image height in pixels */
+	uint32_t stride_;			/**< Row stride in bytes */
+	uint32_t offset_;			/**< Buffer offset (reserved for future use) */
+	uint32_t framesize_;			/**< Total frame size in bytes (stride * height) */
+	uint32_t bpp_;				/**< Bytes per pixel */
+	uint32_t texture_unit_uniform_id_;	/**< Shader uniform id for texture unit */
+	GLenum texture_unit_;			/**< Texture unit associated with this image eg (GL_TEXTURE0) */
+	GLuint texture_;			/**< OpenGL texture object ID */
+	GLuint fbo_;				/**< OpenGL frame buffer object ID */
+	EGLImageKHR image_;			/**< EGL Image handle */
+
+private:
+	LIBCAMERA_DISABLE_COPY_AND_MOVE(eGLImage)
+
+	/**
+	 * \brief Initialise eGLImage state
+	 * \param[in] width Image width in pixels
+	 * \param[in] height Image height in pixels
+	 * \param[in] bpp Bytes per pixel
+	 * \param[in] stride Row stride in bytes
+	 * \param[in] texture_unit OpenGL texture unit
+	 * \param[in] texture_unit_uniform_id Shader uniform ID
+	 *
+	 * Common initialisation routine called by both constructors. Sets up
+	 * member variables and generates OpenGL texture and framebuffer objects.
+	 */
+	void init(uint32_t width, uint32_t height, uint32_t bpp, uint32_t stride, GLenum texture_unit, uint32_t texture_unit_uniform_id)
+	{
+		image_ = EGL_NO_IMAGE_KHR;
+		width_ = width;
+		height_ = height;
+		bpp_ = bpp;
+		stride_ = stride;
+		framesize_ = stride_ * height_;
+		texture_unit_ = texture_unit;
+		texture_unit_uniform_id_ = texture_unit_uniform_id;
+
+		glGenTextures(1, &texture_);
+		glGenFramebuffers(1, &fbo_);
+	}
+};
+
+/**
+ * \class eGL
+ * \brief Helper class for managing OpenGL ES operations
+ *
+ * It provides:
+ *
+ * - EGL context setup and management
+ * - Extension function pointer retrieval
+ * - Shader compilation and program linking
+ * - DMA-BUF texture creation and management
+ * - Synchronisation primitives
+ *
+ * This class is designed to work with zero-copy buffers via DMA-BUF file
+ * descriptors.
+ */
+class eGL
+{
+public:
+	/**
+	 * \brief Construct an EGL helper
+	 *
+	 * Creates an eGL instance with uninitialised context. Call initEGLContext()
+	 * to set up the EGL display, context, and load extension functions.
+	 */
+	eGL();
+
+	/**
+	 * \brief Destroy the EGL helper
+	 *
+	 * Destroys the EGL context and surface if they were successfully created.
+	 */
+	~eGL();
+
+	/**
+	 * \brief Initialise the EGL context
+	 * \param[in] gbmContext Pointer to initialised GBM context
+	 *
+	 * Sets up the EGL display from the GBM device, creates an OpenGL ES 2.0
+	 * context, and retrieves function pointers for required extensions
+	 * including:
+	 * - eglCreateImageKHR / eglDestroyImageKHR
+	 * - glEGLImageTargetTexture2DOES
+	 * - eglCreateSyncKHR / eglDestroySyncKHR / eglClientWaitSyncKHR
+	 *
+	 * \return 0 on success, or -ENODEV on failure
+	 */
+	int initEGLContext(GBM *gbmContext);
+
+	/**
+	 * \brief Clean up EGL resources
+	 *
+	 * Destroys the EGL sync object. Must be called from the same thread
+	 * that created the EGL context.
+	 */
+	void cleanUp();
+
+	/**
+	 * \brief Create an input DMA-BUF backed texture
+	 * \param[in,out] eglImage EGL image to associate with the DMA-BUF
+	 * \param[in] fd DMA-BUF file descriptor
+	 *
+	 * Creates an EGL image from a DMA-BUF file descriptor and binds it to
+	 * a 2D texture for use as an input texture in shaders. The texture is
+	 * configured with nearest filtering and clamp-to-edge wrapping.
+	 *
+	 * \return 0 on success, or -ENODEV on failure
+	 */
+	int createInputDMABufTexture2D(eGLImage *eglImage, int fd);
+
+	/**
+	 * \brief Create an output DMA-BUF backed texture
+	 * \param[in,out] eglImage EGL image to associate with the DMA-BUF
+	 * \param[in] fd DMA-BUF file descriptor
+	 *
+	 * Creates an EGL image from a DMA-BUF file descriptor and binds it to
+	 * a 2D texture, then attaches it to a framebuffer object for use as a
+	 * render target. This enables zero-copy rendering directly to the
+	 * DMA-BUF.
+	 *
+	 * \return 0 on success, or -ENODEV on failure
+	 */
+	int createOutputDMABufTexture2D(eGLImage *eglImage, int fd);
+
+	/**
+	 * \brief Destroy a DMA-BUF texture's EGL image
+	 * \param[in,out] eglImage EGL image to destroy
+	 *
+	 * Destroys the EGL image associated with a DMA-BUF texture. The OpenGL
+	 * texture and framebuffer objects are destroyed separately in the
+	 * eGLImage destructor.
+	 */
+	void destroyDMABufTexture(eGLImage *eglImage);
+
+	/**
+	 * \brief Create a 2D texture from a memory buffer
+	 * \param[in,out] eglImage EGL image to associate with the texture
+	 * \param[in] format OpenGL internal format (e.g., GL_RGB, GL_RGBA)
+	 * \param[in] width Texture width in pixels
+	 * \param[in] height Texture height in pixels
+	 * \param[in] data Pointer to pixel data, or nullptr for uninitialised texture
+	 *
+	 * Creates a 2D texture from a CPU-accessible memory buffer. The texture
+	 * is configured with nearest filtering and clamp-to-edge wrapping. This
+	 * is useful for uploading static data like lookup tables or uniform color
+	 * matrices to the GPU.
+	 */
+	void createTexture2D(eGLImage *eglImage, GLint format, uint32_t width, uint32_t height, void *data);
+
+	/**
+	 * \brief Create a 1D texture from a memory buffer
+	 * \param[in,out] eglImage EGL image to associate with the texture
+	 * \param[in] format OpenGL internal format
+	 * \param[in] width Texture width in pixels
+	 * \param[in] data Pointer to pixel data
+	 *
+	 * Creates a 1D texture (implemented as a 2D texture with height=1) from
+	 * a CPU-accessible memory buffer. Useful for lookup tables in shaders.
+	 */
+	void createTexture1D(eGLImage *eglImage, GLint format, uint32_t width, void *data);
+
+	/**
+	 * \brief Add a preprocessor definition to shader environment
+	 * \param[in,out] shaderEnv Vector of shader environment strings
+	 * \param[in] str Preprocessor definition string (e.g., "#define APPLY_RGB_PARAMETERS")
+	 *
+	 * Appends a preprocessor definition to the shader environment vector.
+	 * These definitions are prepended to shader source code during compilation.
+	 */
+	void pushEnv(std::vector<std::string> &shaderEnv, const char *str);
+
+	/**
+	 * \brief Make the EGL context current for the calling thread
+	 *
+	 * Binds the EGL context to the current thread, allowing OpenGL ES
+	 * operations to be performed. Must be called from the thread that
+	 * will perform rendering operations.
+	 */
+	void makeCurrent();
+
+	/**
+	 * \brief Compile a vertex shader
+	 * \param[out] shaderId OpenGL shader object ID
+	 * \param[in] shaderData Pointer to shader source code
+	 * \param[in] shaderDataLen Length of shader source in bytes
+	 * \param[in] shaderEnv Span of preprocessor definitions to prepend
+	 *
+	 * Compiles a vertex shader from source code with optional preprocessor
+	 * definitions. On compilation failure, logs the shader info log.
+	 *
+	 * \return 0 on success, or -EINVAL on compilation failure
+	 */
+	int compileVertexShader(GLuint &shaderId, unsigned char *shaderData,
+				unsigned int shaderDataLen,
+				Span<const std::string> shaderEnv);
+
+	/**
+	 * \brief Compile a fragment shader
+	 * \param[out] shaderId OpenGL shader object ID
+	 * \param[in] shaderData Pointer to shader source code
+	 * \param[in] shaderDataLen Length of shader source in bytes
+	 * \param[in] shaderEnv Span of preprocessor definitions to prepend
+	 *
+	 * Compiles a fragment shader from source code with optional preprocessor
+	 * definitions. On compilation failure, logs the shader info log.
+	 *
+	 * \return 0 on success, or -EINVAL on compilation failure
+	 */
+	int compileFragmentShader(GLuint &shaderId, unsigned char *shaderData,
+				  unsigned int shaderDataLen,
+				  Span<const std::string> shaderEnv);
+
+	/**
+	 * \brief Link a shader program
+	 * \param[out] programId OpenGL program object ID
+	 * \param[in] fragmentshaderId Compiled fragment shader ID
+	 * \param[in] vertexshaderId Compiled vertex shader ID
+	 *
+	 * Links vertex and fragment shaders into an executable shader program.
+	 * On link failure, logs the program info log and deletes the program.
+	 *
+	 * \return 0 on success, or -ENODEV on link failure
+	 */
+	int linkProgram(GLuint &programId, GLuint fragmentshaderId, GLuint vertexshaderId);
+
+	/**
+	 * \brief Dump shader source code to the log
+	 * \param[in] shaderId OpenGL shader object ID
+	 *
+	 * Retrieves and logs the complete source code of a compiled shader.
+	 * Useful for debugging shader compilation issues.
+	 */
+	void dumpShaderSource(GLuint shaderId);
+
+	/**
+	 * \brief Activate a shader program for rendering
+	 * \param[in] programId OpenGL program object ID
+	 *
+	 * Sets the specified program as the current rendering program. All
+	 * subsequent draw calls will use this program's shaders.
+	 */
+	void useProgram(GLuint programId);
+
+	/**
+	 * \brief Delete a shader program
+	 * \param[in] programId OpenGL program object ID
+	 *
+	 * Deletes a shader program and frees associated resources. The program
+	 * must not be currently in use.
+	 */
+	void deleteProgram(GLuint programId);
+
+	/**
+	 * \brief Synchronise rendering output
+	 *
+	 * Flushes OpenGL commands and waits for rendering to complete using an
+	 * EGL fence sync object. This ensures all rendering operations have
+	 * finished before the CPU accesses the output buffers.
+	 *
+	 * \return 0 on success
+	 */
+	int syncOutput();
+
+private:
+	LIBCAMERA_DISABLE_COPY_AND_MOVE(eGL)
+
+	int fd_;		/**< File descriptor \todo remove this */
+	pid_t tid_;		/**< Thread ID of the thread associated with this EGL context */
+
+	EGLDisplay display_;	/**< EGL display handle */
+	EGLContext context_;	/**< EGL context handle */
+	EGLSurface surface_;	/**< EGL sufrace handle */
+	EGLSyncKHR sync_;	/**< EGL sync object for output sychonisation */
+
+	/**
+	 * \brief Compile a shader of specified type
+	 * \param[in] shaderType GL_VERTEX_SHADER or GL_FRAGMENT_SHADER
+	 * \param[out] shaderId OpenGL shader object ID
+	 * \param[in] shaderData Pointer to shader source code
+	 * \param[in] shaderDataLen Length of shader source in bytes
+	 * \param[in] shaderEnv Span of preprocessor definitions to prepend
+	 *
+	 * Internal helper function for shader compilation. Prepends environment
+	 * definitions to the shader source and compiles the shader.
+	 *
+	 * \return 0 on success, or -EINVAL on compilation failure
+	 */
+	int compileShader(int shaderType, GLuint &shaderId, unsigned char *shaderData,
+			  unsigned int shaderDataLen,
+			  Span<const std::string> shaderEnv);
+
+	/**
+	 * \brief Create a DMA-BUF backed 2D texture
+	 * \param[in,out] eglImage EGL image to associate with the DMA-BUF
+	 * \param[in] fd DMA-BUF file descriptor
+	 * \param[in] output If true, create framebuffer for render target
+	 *
+	 * Internal implementation for creating DMA-BUF textures. Creates an EGL
+	 * image from the DMA-BUF and binds it to a 2D texture. If output is true,
+	 * also creates and attaches a framebuffer object.
+	 *
+	 * \return 0 on success, or -ENODEV on failure
+	 */
+	int createDMABufTexture2D(eGLImage *eglImage, int fd, bool output);
+
+	PFNEGLEXPORTDMABUFIMAGEMESAPROC eglExportDMABUFImageMESA;
+	PFNGLEGLIMAGETARGETTEXTURE2DOESPROC glEGLImageTargetTexture2DOES;
+
+	PFNEGLCREATEIMAGEKHRPROC eglCreateImageKHR;
+	PFNEGLDESTROYIMAGEKHRPROC eglDestroyImageKHR;
+
+	PFNEGLCREATESYNCKHRPROC eglCreateSyncKHR;
+	PFNEGLDESTROYSYNCKHRPROC eglDestroySyncKHR;
+	PFNEGLCLIENTWAITSYNCKHRPROC eglClientWaitSyncKHR;
+};
+} //namespace libcamera
diff --git a/src/libcamera/egl.cpp b/src/libcamera/egl.cpp
new file mode 100644
index 000000000..52d6a6249
--- /dev/null
+++ b/src/libcamera/egl.cpp
@@ -0,0 +1,436 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Linaro Ltd.
+ *
+ * Authors:
+ * Bryan O'Donoghue <bryan.odonoghue@linaro.org>
+ *
+ * egl.cpp - Helper class for managing eGL interactions.
+ */
+
+#include "libcamera/base/thread.h"
+#include "libcamera/internal/egl.h"
+
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include <libdrm/drm_fourcc.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+
+namespace libcamera {
+
+LOG_DEFINE_CATEGORY(eGL)
+
+eGL::eGL()
+{
+	context_ = EGL_NO_CONTEXT;
+	surface_ = EGL_NO_SURFACE;
+	display_ = EGL_NO_DISPLAY;
+}
+
+eGL::~eGL()
+{
+	if (context_ != EGL_NO_CONTEXT)
+		eglDestroyContext(display_, context_);
+
+	if (surface_ != EGL_NO_SURFACE)
+		eglDestroySurface(display_, surface_);
+
+}
+
+int eGL::syncOutput(void)
+{
+	ASSERT(tid_ == Thread::currentId());
+
+	glFlush();
+	eglClientWaitSyncKHR(display_, sync_, 0, EGL_FOREVER_KHR);
+
+	return 0;
+}
+
+// Create linear image attached to previous BO object
+int eGL::createDMABufTexture2D(eGLImage *eglImage, int fd, bool output)
+{
+	int ret = 0;
+
+	ASSERT(tid_ == Thread::currentId());
+
+	// clang-format off
+	EGLint image_attrs[] = {
+		EGL_WIDTH, (EGLint)eglImage->width_,
+		EGL_HEIGHT, (EGLint)eglImage->height_,
+		EGL_LINUX_DRM_FOURCC_EXT, DRM_FORMAT_ARGB8888,
+		EGL_DMA_BUF_PLANE0_FD_EXT, fd,
+		EGL_DMA_BUF_PLANE0_OFFSET_EXT, 0,
+		EGL_DMA_BUF_PLANE0_PITCH_EXT, (EGLint)eglImage->stride_,
+		EGL_DMA_BUF_PLANE0_MODIFIER_LO_EXT, 0,
+		EGL_DMA_BUF_PLANE0_MODIFIER_HI_EXT, 0,
+		EGL_NONE,
+	};
+	// clang-format on
+
+	eglImage->image_ = eglCreateImageKHR(display_, EGL_NO_CONTEXT,
+					     EGL_LINUX_DMA_BUF_EXT,
+					     NULL, image_attrs);
+
+	if (eglImage->image_ == EGL_NO_IMAGE_KHR) {
+		LOG(eGL, Error) << "eglCreateImageKHR fail";
+		ret = -ENODEV;
+		goto done;
+	}
+
+	// Bind texture unit and texture
+	glActiveTexture(eglImage->texture_unit_);
+	glBindTexture(GL_TEXTURE_2D, eglImage->texture_);
+
+	// Generate texture with filter semantics
+	glEGLImageTargetTexture2DOES(GL_TEXTURE_2D, eglImage->image_);
+
+	// Nearest filtering
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+	// Wrap to edge to avoid edge artifacts
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+	if (output) {
+		// Generate a framebuffer from our texture direct to dma-buf handle buffer
+		glBindFramebuffer(GL_FRAMEBUFFER, eglImage->fbo_);
+		glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, eglImage->texture_, 0);
+
+		GLenum err = glCheckFramebufferStatus(GL_FRAMEBUFFER);
+		if (err!= GL_FRAMEBUFFER_COMPLETE) {
+			LOG(eGL, Error) << "glFrameBufferTexture2D error " << err;
+			eglDestroyImageKHR(display_, eglImage->image_);
+			ret = -ENODEV;
+			goto done;
+		}
+	}
+done:
+	return ret;
+}
+
+int eGL::createInputDMABufTexture2D(eGLImage *eglImage, int fd)
+{
+	ASSERT(tid_ == Thread::currentId());
+
+	return createDMABufTexture2D(eglImage, fd, false);
+}
+int eGL::createOutputDMABufTexture2D(eGLImage *eglImage, int fd)
+{
+	ASSERT(tid_ == Thread::currentId());
+
+	return createDMABufTexture2D(eglImage, fd, true);
+}
+
+void eGL::destroyDMABufTexture(eGLImage *eglImage)
+{
+	eglDestroyImage(display_, eglImage->image_);
+}
+
+// Generate a 2D texture from an input buffer directly
+void eGL::createTexture2D(eGLImage *eglImage, GLint format, uint32_t width, uint32_t height, void *data)
+{
+	ASSERT(tid_ == Thread::currentId());
+
+	glActiveTexture(eglImage->texture_unit_);
+	glBindTexture(GL_TEXTURE_2D, eglImage->texture_);
+
+	// Generate texture, bind, associate image to texture, configure, unbind
+	glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
+
+	// Nearest filtering
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+	// Wrap to edge to avoid edge artifacts
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+}
+
+int eGL::initEGLContext(GBM *gbmContext)
+{
+	EGLint configAttribs[] = {
+		EGL_RED_SIZE, 8,
+		EGL_GREEN_SIZE, 8,
+		EGL_BLUE_SIZE, 8,
+		EGL_ALPHA_SIZE, 8,
+		EGL_SURFACE_TYPE, EGL_WINDOW_BIT,
+		EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
+		EGL_NONE
+	};
+
+	EGLint contextAttribs[] = {
+		EGL_CONTEXT_MAJOR_VERSION, 2,
+		EGL_NONE
+	};
+
+	EGLint numConfigs;
+	EGLConfig config;
+	EGLint major;
+	EGLint minor;
+
+	if (!eglBindAPI(EGL_OPENGL_ES_API)) {
+		LOG(eGL, Error) << "API bind fail";
+		goto fail;
+	}
+
+	display_ = eglGetDisplay(gbmContext->getDevice());
+	if (display_ == EGL_NO_DISPLAY) {
+		LOG(eGL, Error) << "Unable to get EGL display";
+		goto fail;
+	}
+
+	if (eglInitialize(display_, &major, &minor) != EGL_TRUE) {
+		LOG(eGL, Error) << "eglInitialize fail";
+		goto fail;
+	}
+
+	LOG(eGL, Info) << "EGL: version " << major << "." << minor;
+	LOG(eGL, Info) << "EGL: EGL_VERSION: " << eglQueryString(display_, EGL_VERSION);
+	LOG(eGL, Info) << "EGL: EGL_VENDOR: " << eglQueryString(display_, EGL_VENDOR);
+	LOG(eGL, Info) << "EGL: EGL_CLIENT_APIS: " << eglQueryString(display_, EGL_CLIENT_APIS);
+	LOG(eGL, Info) << "EGL: EGL_EXTENSIONS: " << eglQueryString(display_, EGL_EXTENSIONS);
+
+	eglCreateImageKHR = (PFNEGLCREATEIMAGEKHRPROC)eglGetProcAddress("eglCreateImageKHR");
+	if (!eglCreateImageKHR) {
+		LOG(eGL, Error) << "eglCreateImageKHR not found";
+		goto fail;
+	}
+
+	eglDestroyImageKHR = (PFNEGLDESTROYIMAGEKHRPROC)eglGetProcAddress("eglDestroyImageKHR");
+	if (!eglDestroyImageKHR) {
+		LOG(eGL, Error) << "eglDestroyImageKHR not found";
+		goto fail;
+	}
+
+	glEGLImageTargetTexture2DOES = (PFNGLEGLIMAGETARGETTEXTURE2DOESPROC)eglGetProcAddress("glEGLImageTargetTexture2DOES");
+	if (!glEGLImageTargetTexture2DOES) {
+		LOG(eGL, Error) << "glEGLImageTargetTexture2DOES not found";
+		goto fail;
+	}
+
+	eglCreateSyncKHR = (PFNEGLCREATESYNCKHRPROC)eglGetProcAddress("eglCreateSyncKHR");
+	if (!eglCreateSyncKHR) {
+		LOG(eGL, Error) << "eglCreateSyncKHR not found";
+		goto fail;
+	}
+
+	eglDestroySyncKHR = (PFNEGLDESTROYSYNCKHRPROC)eglGetProcAddress("eglDestroySyncKHR");
+	if (!eglDestroySyncKHR) {
+		LOG(eGL, Error) << "eglDestroySyncKHR not found";
+		goto fail;
+	}
+
+	eglClientWaitSyncKHR = (PFNEGLCLIENTWAITSYNCKHRPROC)eglGetProcAddress("eglClientWaitSyncKHR");
+	if (!eglClientWaitSyncKHR) {
+		LOG(eGL, Error) << "eglClientWaitSyncKHR not found";
+		goto fail;
+	}
+
+	if (eglChooseConfig(display_, configAttribs, &config, 1, &numConfigs) != EGL_TRUE) {
+		LOG(eGL, Error) << "eglChooseConfig fail";
+		goto fail;
+	}
+
+	context_ = eglCreateContext(display_, config, EGL_NO_CONTEXT, contextAttribs);
+	if (context_ == EGL_NO_CONTEXT) {
+		LOG(eGL, Error) << "eglContext returned EGL_NO_CONTEXT";
+		goto fail;
+	}
+
+	tid_ = Thread::currentId();
+
+	makeCurrent();
+
+	sync_ = eglCreateSyncKHR(display_, EGL_SYNC_FENCE_KHR, NULL);
+	if (sync_ == EGL_NO_SYNC_KHR) {
+		LOG(eGL, Error) << "eglCreateSyncKHR fail";
+		goto fail;
+	}
+
+	return 0;
+fail:
+
+	return -ENODEV;
+}
+
+void eGL::cleanUp(void)
+{
+	ASSERT(tid_ == Thread::currentId());
+
+	if (sync_) {
+		makeCurrent();
+		eglDestroySyncKHR(display_, sync_);
+	}
+
+}
+
+void eGL::makeCurrent(void)
+{
+	ASSERT(tid_ == Thread::currentId());
+
+	if (eglMakeCurrent(display_, EGL_NO_SURFACE, EGL_NO_SURFACE, context_) != EGL_TRUE) {
+		LOG(eGL, Error) << "eglMakeCurrent fail";
+	}
+}
+
+void eGL::useProgram(GLuint programId)
+{
+	ASSERT(tid_ == Thread::currentId());
+
+	glUseProgram(programId);
+}
+
+void eGL::deleteProgram(GLuint programId)
+{
+	ASSERT(tid_ == Thread::currentId());
+
+	glDeleteProgram(programId);
+}
+
+void eGL::pushEnv(std::vector<std::string> &shaderEnv, const char *str)
+{
+	std::string addStr = str;
+
+	addStr.push_back('\n');
+	shaderEnv.push_back(std::move(addStr));
+}
+
+int eGL::compileVertexShader(GLuint &shaderId, unsigned char *shaderData,
+			     unsigned int shaderDataLen,
+			     Span<const std::string> shaderEnv)
+{
+	return compileShader(GL_VERTEX_SHADER, shaderId, shaderData, shaderDataLen, shaderEnv);
+}
+
+int eGL::compileFragmentShader(GLuint &shaderId, unsigned char *shaderData,
+			       unsigned int shaderDataLen,
+			       Span<const std::string> shaderEnv)
+{
+	return compileShader(GL_FRAGMENT_SHADER, shaderId, shaderData, shaderDataLen, shaderEnv);
+}
+
+int eGL::compileShader(int shaderType, GLuint &shaderId, unsigned char *shaderData,
+		       unsigned int shaderDataLen,
+		       Span<const std::string> shaderEnv)
+{
+	GLint success;
+	size_t i;
+
+	ASSERT(tid_ == Thread::currentId());
+
+	auto count = 1 + shaderEnv.size();
+	auto shaderSourceData = std::make_unique<const GLchar*[]>(count);
+	auto shaderDataLengths = std::make_unique<GLint[]>(count);
+
+	// Prefix defines before main body of shader
+	for (i = 0; i < shaderEnv.size(); i++) {
+		shaderSourceData[i] = shaderEnv[i].c_str();
+		shaderDataLengths[i] = shaderEnv[i].length();
+	}
+
+	// Now the main body of the shader program
+	shaderSourceData[i] = reinterpret_cast<const GLchar*>(shaderData);
+	shaderDataLengths[i] = shaderDataLen;
+
+	// And create the shader
+	shaderId = glCreateShader(shaderType);
+	glShaderSource(shaderId, count, shaderSourceData.get(), shaderDataLengths.get());
+	glCompileShader(shaderId);
+
+	// Check status
+	glGetShaderiv(shaderId, GL_COMPILE_STATUS, &success);
+	if (success == GL_FALSE) {
+		GLint sizeLog = 0;
+
+		glGetShaderiv(shaderId, GL_INFO_LOG_LENGTH, &sizeLog);
+		auto infoLog = std::make_unique<GLchar[]>(sizeLog);
+
+		glGetShaderInfoLog(shaderId, sizeLog, &sizeLog, infoLog.get());
+		LOG(eGL, Error) << infoLog.get();
+	}
+
+	return (success == GL_TRUE) ? 0 : -EINVAL;
+}
+
+void eGL::dumpShaderSource(GLuint shaderId)
+{
+	GLint shaderLength = 0;
+
+	ASSERT(tid_ == Thread::currentId());
+
+	glGetShaderiv(shaderId, GL_SHADER_SOURCE_LENGTH, &shaderLength);
+
+	LOG(eGL, Debug) << "Shader length is " << shaderLength;
+
+	if (shaderLength > 0) {
+		auto shaderSource = std::make_unique<GLchar []>(shaderLength);
+
+		glGetShaderSource(shaderId, shaderLength, &shaderLength, shaderSource.get());
+		if (shaderLength) {
+			LOG(eGL, Debug) << "Shader source = " << shaderSource.get();
+		}
+	}
+}
+
+int eGL::linkProgram(GLuint &programId, GLuint vertexshaderId, GLuint fragmentshaderId)
+{
+	GLint success;
+	GLenum err;
+
+	ASSERT(tid_ == Thread::currentId());
+
+	programId = glCreateProgram();
+	if (!programId)
+		goto fail;
+
+	glAttachShader(programId, vertexshaderId);
+	if ((err = glGetError()) != GL_NO_ERROR) {
+		LOG(eGL, Error) << "Attach compute vertex shader fail";
+		goto fail;
+	}
+
+	glAttachShader(programId, fragmentshaderId);
+	if ((err = glGetError()) != GL_NO_ERROR) {
+		LOG(eGL, Error) << "Attach compute vertex shader fail";
+		goto fail;
+	}
+
+	glLinkProgram(programId);
+	if ((err = glGetError()) != GL_NO_ERROR) {
+		LOG(eGL, Error) << "Link program fail";
+		goto fail;
+	}
+
+	glDetachShader(programId, fragmentshaderId);
+	glDetachShader(programId, vertexshaderId);
+
+	// Check status
+	glGetProgramiv(programId, GL_LINK_STATUS, &success);
+	if (success == GL_FALSE) {
+		GLint sizeLog = 0;
+		GLchar *infoLog;
+
+		glGetProgramiv(programId, GL_INFO_LOG_LENGTH, &sizeLog);
+		infoLog = new GLchar[sizeLog];
+
+		glGetProgramInfoLog(programId, sizeLog, &sizeLog, infoLog);
+		LOG(eGL, Error) << infoLog;
+
+		delete[] infoLog;
+		goto fail;
+	}
+
+	return 0;
+fail:
+	if (programId)
+		glDeleteProgram(programId);
+
+	return -ENODEV;
+}
+} // namespace libcamera
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index fe60c8752..b7be38a8f 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -79,6 +79,27 @@  if libgbm.found() and gbm_works
     ])
 endif
 
+libegl = cc.find_library('EGL', required : false)
+libglesv2 = cc.find_library('GLESv2', required : false)
+mesa_works = cc.check_header('EGL/egl.h', required: false)
+
+if libegl.found() and mesa_works
+    config_h.set('HAVE_LIBEGL', 1)
+endif
+
+if libglesv2.found() and mesa_works
+    config_h.set('HAVE_GLESV2', 1)
+endif
+
+if mesa_works and gbm_works
+    libcamera_internal_sources += files([
+        'egl.cpp',
+    ])
+    gles_headless_enabled = true
+else
+    gles_headless_enabled = false
+endif
+
 subdir('base')
 subdir('converter')
 subdir('ipa')
@@ -186,7 +207,9 @@  libcamera_deps += [
     libcamera_base_private,
     libcrypto,
     libdl,
+    libegl,
     libgbm,
+    libglesv2,
     liblttng,
     libudev,
     libyaml,