Adding upstream version 6.338.2.upstream/6.338.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 645 insertions, 0 deletions

diff --git a/src/opengl/gpu.c b/src/opengl/gpu.c
new file mode 100644
index 0000000..b711ac5
--- /dev/null
+++ b/src/opengl/gpu.c
@@ -0,0 +1,645 @@
+/*
+ * This file is part of libplacebo.
+ *
+ * libplacebo is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * libplacebo is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with libplacebo. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "gpu.h"
+#include "common.h"
+#include "formats.h"
+#include "utils.h"
+
+#ifdef PL_HAVE_UNIX
+#include <unistd.h>
+#endif
+
+#ifdef PL_HAVE_WIN32
+#include <windows.h>
+#include <sysinfoapi.h>
+#endif
+
+static const struct pl_gpu_fns pl_fns_gl;
+
+static void gl_gpu_destroy(pl_gpu gpu)
+{
+    struct pl_gl *p = PL_PRIV(gpu);
+
+    pl_gpu_finish(gpu);
+    while (p->callbacks.num > 0)
+        gl_poll_callbacks(gpu);
+
+    pl_free((void *) gpu);
+}
+
+pl_opengl pl_opengl_get(pl_gpu gpu)
+{
+    const struct pl_gpu_fns *impl = PL_PRIV(gpu);
+    if (impl->destroy == gl_gpu_destroy) {
+        struct pl_gl *p = (struct pl_gl *) impl;
+        return p->gl;
+    }
+
+    return NULL;
+}
+
+static pl_handle_caps tex_handle_caps(pl_gpu gpu, bool import)
+{
+    pl_handle_caps caps = 0;
+    struct pl_gl *p = PL_PRIV(gpu);
+
+    if (!p->egl_dpy || (!p->has_egl_storage && !p->has_egl_import))
+        return 0;
+
+    if (import) {
+        if (pl_opengl_has_ext(p->gl, "EGL_EXT_image_dma_buf_import"))
+            caps |= PL_HANDLE_DMA_BUF;
+    } else if (!import && p->egl_ctx) {
+        if (pl_opengl_has_ext(p->gl, "EGL_MESA_image_dma_buf_export"))
+            caps |= PL_HANDLE_DMA_BUF;
+    }
+
+    return caps;
+}
+
+static inline size_t get_page_size(void)
+{
+
+#ifdef PL_HAVE_UNIX
+    return sysconf(_SC_PAGESIZE);
+#endif
+
+#ifdef PL_HAVE_WIN32
+    SYSTEM_INFO sysInfo;
+    GetSystemInfo(&sysInfo);
+    return sysInfo.dwAllocationGranularity;
+#endif
+
+    pl_assert(!"Unsupported platform!");
+}
+
+#define get(pname, field)                   \
+    do {                                    \
+        GLint tmp = 0;                      \
+        gl->GetIntegerv((pname), &tmp);     \
+        *(field) = tmp;                     \
+    } while (0)
+
+#define geti(pname, i, field)               \
+    do {                                    \
+        GLint tmp = 0;                      \
+        gl->GetIntegeri_v((pname), i, &tmp);\
+        *(field) = tmp;                     \
+    } while (0)
+
+pl_gpu pl_gpu_create_gl(pl_log log, pl_opengl pl_gl, const struct pl_opengl_params *params)
+{
+    struct pl_gpu_t *gpu = pl_zalloc_obj(NULL, gpu, struct pl_gl);
+    gpu->log = log;
+
+    struct pl_gl *p = PL_PRIV(gpu);
+    p->impl = pl_fns_gl;
+    p->gl = pl_gl;
+
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    struct pl_glsl_version *glsl = &gpu->glsl;
+    glsl->gles = gl_is_gles(pl_gl);
+    int ver = pl_gl->major * 10 + pl_gl->minor;
+    p->gl_ver = glsl->gles ? 0 : ver;
+    p->gles_ver = glsl->gles ? ver : 0;
+
+    // If possible, query the GLSL version from the implementation
+    const char *glslver = (char *) gl->GetString(GL_SHADING_LANGUAGE_VERSION);
+    if (glslver) {
+        PL_INFO(gpu, "    GL_SHADING_LANGUAGE_VERSION: %s", glslver);
+        int major = 0, minor = 0;
+        if (sscanf(glslver, "%d.%d", &major, &minor) == 2)
+            glsl->version = major * 100 + minor;
+    }
+
+    if (!glsl->version) {
+        // Otherwise, use the fixed magic versions 100 and 300 for GLES.
+        if (p->gles_ver >= 30) {
+            glsl->version = 300;
+        } else if (p->gles_ver >= 20) {
+            glsl->version = 100;
+        } else {
+            goto error;
+        }
+    }
+
+    static const int glsl_ver_req = 130;
+    if (glsl->version < glsl_ver_req) {
+        PL_FATAL(gpu, "GLSL version too old (%d < %d), please use a newer "
+                 "OpenGL implementation or downgrade libplacebo!",
+                 glsl->version, glsl_ver_req);
+        goto error;
+    }
+
+    if (params->max_glsl_version && params->max_glsl_version >= glsl_ver_req) {
+        glsl->version = PL_MIN(glsl->version, params->max_glsl_version);
+        PL_INFO(gpu, "Restricting GLSL version to %d... new version is %d",
+                params->max_glsl_version, glsl->version);
+    }
+
+    if (gl_test_ext(gpu, "GL_ARB_compute_shader", 43, 0) && glsl->version >= 420) {
+        glsl->compute = true;
+        get(GL_MAX_COMPUTE_SHARED_MEMORY_SIZE, &glsl->max_shmem_size);
+        get(GL_MAX_COMPUTE_WORK_GROUP_INVOCATIONS, &glsl->max_group_threads);
+        for (int i = 0; i < 3; i++)
+            geti(GL_MAX_COMPUTE_WORK_GROUP_SIZE, i, &glsl->max_group_size[i]);
+    }
+
+    if (gl_test_ext(gpu, "GL_ARB_texture_gather", 40, 0)) {
+        get(GL_MAX_PROGRAM_TEXTURE_GATHER_COMPONENTS_ARB, &p->gather_comps);
+        get(GL_MIN_PROGRAM_TEXTURE_GATHER_OFFSET_ARB, &glsl->min_gather_offset);
+        get(GL_MAX_PROGRAM_TEXTURE_GATHER_OFFSET_ARB, &glsl->max_gather_offset);
+    }
+
+    // Query all device limits
+    struct pl_gpu_limits *limits = &gpu->limits;
+    limits->thread_safe = params->make_current;
+    limits->callbacks = gl_test_ext(gpu, "GL_ARB_sync", 32, 30);
+    limits->align_vertex_stride = 1;
+    if (gl_test_ext(gpu, "GL_ARB_pixel_buffer_object", 31, 0)) {
+        limits->max_buf_size = SIZE_MAX; // no restriction imposed by GL
+        if (gl_test_ext(gpu, "GL_ARB_uniform_buffer_object", 31, 0))
+            get(GL_MAX_UNIFORM_BLOCK_SIZE, &limits->max_ubo_size);
+        if (gl_test_ext(gpu, "GL_ARB_shader_storage_buffer_object", 43, 0) &&
+            gpu->glsl.version >= 140)
+        {
+            get(GL_MAX_SHADER_STORAGE_BLOCK_SIZE, &limits->max_ssbo_size);
+        }
+        limits->max_vbo_size = limits->max_buf_size; // No additional restrictions
+        if (gl_test_ext(gpu, "GL_ARB_buffer_storage", 44, 0)) {
+            const char *vendor = (char *) gl->GetString(GL_VENDOR);
+            limits->max_mapped_size = limits->max_buf_size;
+            limits->host_cached = strcmp(vendor, "AMD") == 0 ||
+                                  strcmp(vendor, "NVIDIA Corporation") == 0;
+        }
+    }
+
+    get(GL_MAX_TEXTURE_SIZE, &limits->max_tex_2d_dim);
+    if (gl_test_ext(gpu, "GL_EXT_texture3D", 21, 30))
+        get(GL_MAX_3D_TEXTURE_SIZE, &limits->max_tex_3d_dim);
+    // There's no equivalent limit for 1D textures for whatever reason, so
+    // just set it to the same as the 2D limit
+    if (p->gl_ver >= 21)
+        limits->max_tex_1d_dim = limits->max_tex_2d_dim;
+    limits->buf_transfer = true;
+
+    if (p->gl_ver || p->gles_ver >= 30) {
+        get(GL_MAX_FRAGMENT_UNIFORM_COMPONENTS, &limits->max_variable_comps);
+    } else {
+        // fallback for GLES 2.0, which doesn't have max_comps
+        get(GL_MAX_FRAGMENT_UNIFORM_VECTORS, &limits->max_variable_comps);
+        limits->max_variable_comps *= 4;
+    }
+
+    if (glsl->compute) {
+        for (int i = 0; i < 3; i++)
+            geti(GL_MAX_COMPUTE_WORK_GROUP_COUNT, i, &limits->max_dispatch[i]);
+    }
+
+    // Query import/export support
+    p->egl_dpy = params->egl_display;
+    p->egl_ctx = params->egl_context;
+    p->has_egl_storage = pl_opengl_has_ext(p->gl, "GL_EXT_EGL_image_storage");
+    p->has_egl_import = pl_opengl_has_ext(p->gl, "GL_OES_EGL_image_external");
+    gpu->export_caps.tex = tex_handle_caps(gpu, false);
+    gpu->import_caps.tex = tex_handle_caps(gpu, true);
+
+    if (p->egl_dpy) {
+        p->has_modifiers = pl_opengl_has_ext(p->gl,
+                                        "EGL_EXT_image_dma_buf_import_modifiers");
+    }
+
+    if (pl_opengl_has_ext(pl_gl, "GL_AMD_pinned_memory")) {
+        gpu->import_caps.buf |= PL_HANDLE_HOST_PTR;
+        gpu->limits.align_host_ptr = get_page_size();
+    }
+
+    // Cache some internal capability checks
+    p->has_vao = gl_test_ext(gpu, "GL_ARB_vertex_array_object", 30, 0);
+    p->has_invalidate_fb = gl_test_ext(gpu, "GL_ARB_invalidate_subdata", 43, 30);
+    p->has_invalidate_tex = gl_test_ext(gpu, "GL_ARB_invalidate_subdata", 43, 0);
+    p->has_queries = gl_test_ext(gpu, "GL_ARB_timer_query", 33, 0);
+    p->has_storage = gl_test_ext(gpu, "GL_ARB_shader_image_load_store", 42, 0);
+    p->has_readback = true;
+
+    if (p->has_readback && p->gles_ver) {
+        GLuint fbo = 0, tex = 0;
+        GLint read_type = 0, read_fmt = 0;
+        gl->GenTextures(1, &tex);
+        gl->BindTexture(GL_TEXTURE_2D, tex);
+        gl->GenFramebuffers(1, &fbo);
+        gl->TexImage2D(GL_TEXTURE_2D, 0, GL_R8, 64, 64, 0, GL_RED,
+                       GL_UNSIGNED_BYTE, NULL);
+        gl->BindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo);
+        gl->FramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                                 GL_TEXTURE_2D, tex, 0);
+        gl->GetIntegerv(GL_IMPLEMENTATION_COLOR_READ_TYPE, &read_type);
+        gl->GetIntegerv(GL_IMPLEMENTATION_COLOR_READ_FORMAT, &read_fmt);
+        if (read_type != GL_UNSIGNED_BYTE || read_fmt != GL_RED) {
+            PL_INFO(gpu, "GPU does not seem to support lossless texture "
+                    "readback, restricting readback capabilities! This is a "
+                    "GLES/driver limitation, there is little we can do to "
+                    "work around it.");
+            p->has_readback = false;
+        }
+        gl->BindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+        gl->BindTexture(GL_TEXTURE_2D, 0);
+        gl->DeleteFramebuffers(1, &fbo);
+        gl->DeleteTextures(1, &tex);
+    }
+
+    // We simply don't know, so make up some values
+    limits->align_tex_xfer_offset = 32;
+    limits->align_tex_xfer_pitch = 4;
+    limits->fragment_queues = 1;
+    limits->compute_queues = glsl->compute ? 1 : 0;
+
+    if (!gl_check_err(gpu, "pl_gpu_create_gl")) {
+        PL_WARN(gpu, "Encountered errors while detecting GPU capabilities... "
+                "ignoring, but expect limitations/issues");
+        p->failed = false;
+    }
+
+    // Filter out error messages during format probing
+    pl_log_level_cap(gpu->log, PL_LOG_INFO);
+    bool formats_ok = gl_setup_formats(gpu);
+    pl_log_level_cap(gpu->log, PL_LOG_NONE);
+    if (!formats_ok)
+        goto error;
+
+    return pl_gpu_finalize(gpu);
+
+error:
+    gl_gpu_destroy(gpu);
+    return NULL;
+}
+
+void gl_buf_destroy(pl_gpu gpu, pl_buf buf)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    if (!MAKE_CURRENT()) {
+        PL_ERR(gpu, "Failed uninitializing buffer, leaking resources!");
+        return;
+    }
+
+    struct pl_buf_gl *buf_gl = PL_PRIV(buf);
+    if (buf_gl->fence)
+        gl->DeleteSync(buf_gl->fence);
+
+    if (buf_gl->mapped) {
+        gl->BindBuffer(GL_COPY_WRITE_BUFFER, buf_gl->buffer);
+        gl->UnmapBuffer(GL_COPY_WRITE_BUFFER);
+        gl->BindBuffer(GL_COPY_WRITE_BUFFER, 0);
+    }
+
+    gl->DeleteBuffers(1, &buf_gl->buffer);
+    gl_check_err(gpu, "gl_buf_destroy");
+    RELEASE_CURRENT();
+    pl_free((void *) buf);
+}
+
+pl_buf gl_buf_create(pl_gpu gpu, const struct pl_buf_params *params)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    if (!MAKE_CURRENT())
+        return NULL;
+
+    struct pl_buf_t *buf = pl_zalloc_obj(NULL, buf, struct pl_buf_gl);
+    buf->params = *params;
+    buf->params.initial_data = NULL;
+
+    struct pl_gl *p = PL_PRIV(gpu);
+    struct pl_buf_gl *buf_gl = PL_PRIV(buf);
+    buf_gl->id = ++p->buf_id;
+
+    // Just use this since the generic GL_BUFFER doesn't work
+    GLenum target = GL_ARRAY_BUFFER;
+    const void *data = params->initial_data;
+    size_t total_size = params->size;
+    bool import = false;
+
+    if (params->import_handle == PL_HANDLE_HOST_PTR) {
+        const struct pl_shared_mem *shmem = &params->shared_mem;
+        target = GL_EXTERNAL_VIRTUAL_MEMORY_BUFFER_AMD;
+
+        data = shmem->handle.ptr;
+        buf_gl->offset = shmem->offset;
+        total_size = shmem->size;
+        import = true;
+
+        if (params->host_mapped)
+            buf->data = (uint8_t *) data + buf_gl->offset;
+
+        if (buf_gl->offset > 0 && params->drawable) {
+            PL_ERR(gpu, "Cannot combine non-aligned host pointer imports with "
+                   "drawable (vertex) buffers! This is a design limitation, "
+                   "open an issue if you absolutely need this.");
+            goto error;
+        }
+    }
+
+    gl->GenBuffers(1, &buf_gl->buffer);
+    gl->BindBuffer(target, buf_gl->buffer);
+
+    if (gl_test_ext(gpu, "GL_ARB_buffer_storage", 44, 0) && !import) {
+
+        GLbitfield mapflags = 0, storflags = 0;
+        if (params->host_writable)
+            storflags |= GL_DYNAMIC_STORAGE_BIT;
+        if (params->host_mapped) {
+            mapflags |= GL_MAP_READ_BIT | GL_MAP_WRITE_BIT |
+                        GL_MAP_PERSISTENT_BIT | GL_MAP_COHERENT_BIT;
+        }
+        if (params->memory_type == PL_BUF_MEM_HOST)
+            storflags |= GL_CLIENT_STORAGE_BIT; // hopefully this works
+
+        gl->BufferStorage(target, total_size, data, storflags | mapflags);
+
+        if (params->host_mapped) {
+            buf_gl->mapped = true;
+            buf->data = gl->MapBufferRange(target, buf_gl->offset, params->size,
+                                           mapflags);
+            if (!buf->data) {
+                gl->BindBuffer(target, 0);
+                if (!gl_check_err(gpu, "gl_buf_create: map"))
+                    PL_ERR(gpu, "Failed mapping buffer: unknown reason");
+                goto error;
+            }
+        }
+
+    } else {
+
+        // Make a random guess based on arbitrary criteria we can't know
+        GLenum hint = GL_STREAM_DRAW;
+        if (params->initial_data && !params->host_writable && !params->host_mapped)
+            hint = GL_STATIC_DRAW;
+        if (params->host_readable && !params->host_writable && !params->host_mapped)
+            hint = GL_STREAM_READ;
+        if (params->storable)
+            hint = GL_DYNAMIC_COPY;
+
+        gl->BufferData(target, total_size, data, hint);
+
+        if (import && gl->GetError() == GL_INVALID_OPERATION) {
+            PL_ERR(gpu, "Failed importing host pointer!");
+            goto error;
+        }
+
+    }
+
+    gl->BindBuffer(target, 0);
+    if (!gl_check_err(gpu, "gl_buf_create"))
+        goto error;
+
+    if (params->storable) {
+        buf_gl->barrier = GL_BUFFER_UPDATE_BARRIER_BIT | // for buf_copy etc.
+                          GL_PIXEL_BUFFER_BARRIER_BIT | // for tex_upload
+                          GL_SHADER_STORAGE_BARRIER_BIT;
+
+        if (params->host_mapped)
+            buf_gl->barrier |= GL_CLIENT_MAPPED_BUFFER_BARRIER_BIT;
+        if (params->uniform)
+            buf_gl->barrier |= GL_UNIFORM_BARRIER_BIT;
+        if (params->drawable)
+            buf_gl->barrier |= GL_VERTEX_ATTRIB_ARRAY_BARRIER_BIT;
+    }
+
+    RELEASE_CURRENT();
+    return buf;
+
+error:
+    gl_buf_destroy(gpu, buf);
+    RELEASE_CURRENT();
+    return NULL;
+}
+
+bool gl_buf_poll(pl_gpu gpu, pl_buf buf, uint64_t timeout)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+
+    // Non-persistently mapped buffers are always implicitly reusable in OpenGL,
+    // the implementation will create more buffers under the hood if needed.
+    if (!buf->data)
+        return false;
+
+    if (!MAKE_CURRENT())
+        return true; // conservative guess
+
+    struct pl_buf_gl *buf_gl = PL_PRIV(buf);
+    if (buf_gl->fence) {
+        GLenum res = gl->ClientWaitSync(buf_gl->fence,
+                                        timeout ? GL_SYNC_FLUSH_COMMANDS_BIT : 0,
+                                        timeout);
+        if (res == GL_ALREADY_SIGNALED || res == GL_CONDITION_SATISFIED) {
+            gl->DeleteSync(buf_gl->fence);
+            buf_gl->fence = NULL;
+        }
+    }
+
+    gl_poll_callbacks(gpu);
+    RELEASE_CURRENT();
+    return !!buf_gl->fence;
+}
+
+void gl_buf_write(pl_gpu gpu, pl_buf buf, size_t offset,
+                  const void *data, size_t size)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    if (!MAKE_CURRENT())
+        return;
+
+    struct pl_buf_gl *buf_gl = PL_PRIV(buf);
+    gl->BindBuffer(GL_ARRAY_BUFFER, buf_gl->buffer);
+    gl->BufferSubData(GL_ARRAY_BUFFER, buf_gl->offset + offset, size, data);
+    gl->BindBuffer(GL_ARRAY_BUFFER, 0);
+    gl_check_err(gpu, "gl_buf_write");
+    RELEASE_CURRENT();
+}
+
+bool gl_buf_read(pl_gpu gpu, pl_buf buf, size_t offset,
+                 void *dest, size_t size)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    if (!MAKE_CURRENT())
+        return false;
+
+    struct pl_buf_gl *buf_gl = PL_PRIV(buf);
+    gl->BindBuffer(GL_ARRAY_BUFFER, buf_gl->buffer);
+    gl->GetBufferSubData(GL_ARRAY_BUFFER, buf_gl->offset + offset, size, dest);
+    gl->BindBuffer(GL_ARRAY_BUFFER, 0);
+    bool ok = gl_check_err(gpu, "gl_buf_read");
+    RELEASE_CURRENT();
+    return ok;
+}
+
+void gl_buf_copy(pl_gpu gpu, pl_buf dst, size_t dst_offset,
+                 pl_buf src, size_t src_offset, size_t size)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    if (!MAKE_CURRENT())
+        return;
+
+    struct pl_buf_gl *src_gl = PL_PRIV(src);
+    struct pl_buf_gl *dst_gl = PL_PRIV(dst);
+    gl->BindBuffer(GL_COPY_READ_BUFFER, src_gl->buffer);
+    gl->BindBuffer(GL_COPY_WRITE_BUFFER, dst_gl->buffer);
+    gl->CopyBufferSubData(GL_COPY_READ_BUFFER, GL_COPY_WRITE_BUFFER,
+                          src_gl->offset + src_offset,
+                          dst_gl->offset + dst_offset, size);
+    gl_check_err(gpu, "gl_buf_copy");
+    RELEASE_CURRENT();
+}
+
+#define QUERY_OBJECT_NUM 8
+
+struct pl_timer_t {
+    GLuint query[QUERY_OBJECT_NUM];
+    int index_write; // next index to write to
+    int index_read; // next index to read from
+};
+
+static pl_timer gl_timer_create(pl_gpu gpu)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    struct pl_gl *p = PL_PRIV(gpu);
+    if (!p->has_queries || !MAKE_CURRENT())
+        return NULL;
+
+    pl_timer timer = pl_zalloc_ptr(NULL, timer);
+    gl->GenQueries(QUERY_OBJECT_NUM, timer->query);
+    RELEASE_CURRENT();
+    return timer;
+}
+
+static void gl_timer_destroy(pl_gpu gpu, pl_timer timer)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    if (!MAKE_CURRENT()) {
+        PL_ERR(gpu, "Failed uninitializing timer, leaking resources!");
+        return;
+    }
+
+    gl->DeleteQueries(QUERY_OBJECT_NUM, timer->query);
+    gl_check_err(gpu, "gl_timer_destroy");
+    RELEASE_CURRENT();
+    pl_free(timer);
+}
+
+static uint64_t gl_timer_query(pl_gpu gpu, pl_timer timer)
+{
+    if (timer->index_read == timer->index_write)
+        return 0; // no more unprocessed results
+
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    if (!MAKE_CURRENT())
+        return 0;
+
+    uint64_t res = 0;
+    GLuint query = timer->query[timer->index_read];
+    int avail = 0;
+    gl->GetQueryObjectiv(query, GL_QUERY_RESULT_AVAILABLE, &avail);
+    if (!avail)
+        goto done;
+    gl->GetQueryObjectui64v(query, GL_QUERY_RESULT, &res);
+
+    timer->index_read = (timer->index_read + 1) % QUERY_OBJECT_NUM;
+    // fall through
+
+done:
+    RELEASE_CURRENT();
+    return res;
+}
+
+void gl_timer_begin(pl_gpu gpu, pl_timer timer)
+{
+    if (!timer)
+        return;
+
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    gl->BeginQuery(GL_TIME_ELAPSED, timer->query[timer->index_write]);
+}
+
+void gl_timer_end(pl_gpu gpu, pl_timer timer)
+{
+    if (!timer)
+        return;
+
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    gl->EndQuery(GL_TIME_ELAPSED);
+
+    timer->index_write = (timer->index_write + 1) % QUERY_OBJECT_NUM;
+    if (timer->index_write == timer->index_read) {
+        // forcibly drop the least recent result to make space
+        timer->index_read = (timer->index_read + 1) % QUERY_OBJECT_NUM;
+    }
+}
+
+static void gl_gpu_flush(pl_gpu gpu)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    if (!MAKE_CURRENT())
+        return;
+
+    gl->Flush();
+    gl_check_err(gpu, "gl_gpu_flush");
+    RELEASE_CURRENT();
+}
+
+static void gl_gpu_finish(pl_gpu gpu)
+{
+    const gl_funcs *gl = gl_funcs_get(gpu);
+    if (!MAKE_CURRENT())
+        return;
+
+    gl->Finish();
+    gl_check_err(gpu, "gl_gpu_finish");
+    RELEASE_CURRENT();
+}
+
+static bool gl_gpu_is_failed(pl_gpu gpu)
+{
+    struct pl_gl *gl = PL_PRIV(gpu);
+    return gl->failed;
+}
+
+static const struct pl_gpu_fns pl_fns_gl = {
+    .destroy                = gl_gpu_destroy,
+    .tex_create             = gl_tex_create,
+    .tex_destroy            = gl_tex_destroy,
+    .tex_invalidate         = gl_tex_invalidate,
+    .tex_clear_ex           = gl_tex_clear_ex,
+    .tex_blit               = gl_tex_blit,
+    .tex_upload             = gl_tex_upload,
+    .tex_download           = gl_tex_download,
+    .buf_create             = gl_buf_create,
+    .buf_destroy            = gl_buf_destroy,
+    .buf_write              = gl_buf_write,
+    .buf_read               = gl_buf_read,
+    .buf_copy               = gl_buf_copy,
+    .buf_poll               = gl_buf_poll,
+    .desc_namespace         = gl_desc_namespace,
+    .pass_create            = gl_pass_create,
+    .pass_destroy           = gl_pass_destroy,
+    .pass_run               = gl_pass_run,
+    .timer_create           = gl_timer_create,
+    .timer_destroy          = gl_timer_destroy,
+    .timer_query            = gl_timer_query,
+    .gpu_flush              = gl_gpu_flush,
+    .gpu_finish             = gl_gpu_finish,
+    .gpu_is_failed          = gl_gpu_is_failed,
+};