Refactor EGL/GL API loading

Remove glapi.sh code generation, replace it with hand-written loading
code that checks extension strings before calling eglGetProcAddress.

The GLES2 renderer still uses global state because of:

- {PUSH,POP}_GLES2_DEBUG macros
- wlr_gles2_texture_from_* taking a wlr_egl instead of the renderer

2 files changed, 59 insertions, 37 deletions

diff --git a/render/gles2/renderer.c b/render/gles2/renderer.c
index 8bef5137..b5855d4e 100644
--- a/render/gles2/renderer.c
+++ b/render/gles2/renderer.c
@@ -11,9 +11,10 @@
 #include <wlr/render/wlr_renderer.h>
 #include <wlr/types/wlr_matrix.h>
 #include <wlr/util/log.h>
-#include "glapi.h"
 #include "render/gles2.h"
 
+struct wlr_gles2_procs gles2_procs = {0};
+
 static const struct wlr_renderer_impl renderer_impl;
 
 static struct wlr_gles2_renderer *gles2_get_renderer(
@@ -219,13 +220,13 @@ static bool gles2_resource_is_wl_drm_buffer(struct wlr_renderer *wlr_renderer,
 		struct wl_resource *resource) {
 	struct wlr_gles2_renderer *renderer = gles2_get_renderer(wlr_renderer);
 
-	if (!eglQueryWaylandBufferWL) {
+	if (!renderer->egl->exts.bind_wayland_display_wl) {
 		return false;
 	}
 
 	EGLint fmt;
-	return eglQueryWaylandBufferWL(renderer->egl->display, resource,
-		EGL_TEXTURE_FORMAT, &fmt);
+	return renderer->egl->procs.eglQueryWaylandBufferWL(renderer->egl->display,
+		resource, EGL_TEXTURE_FORMAT, &fmt);
 }
 
 static void gles2_wl_drm_buffer_get_size(struct wlr_renderer *wlr_renderer,
@@ -233,12 +234,14 @@ static void gles2_wl_drm_buffer_get_size(struct wlr_renderer *wlr_renderer,
 	struct wlr_gles2_renderer *renderer =
 		gles2_get_renderer(wlr_renderer);
 
-	if (!eglQueryWaylandBufferWL) {
+	if (!renderer->egl->exts.bind_wayland_display_wl) {
 		return;
 	}
 
-	eglQueryWaylandBufferWL(renderer->egl->display, buffer, EGL_WIDTH, width);
-	eglQueryWaylandBufferWL(renderer->egl->display, buffer, EGL_HEIGHT, height);
+	renderer->egl->procs.eglQueryWaylandBufferWL(renderer->egl->display,
+		buffer, EGL_WIDTH, width);
+	renderer->egl->procs.eglQueryWaylandBufferWL(renderer->egl->display,
+		buffer, EGL_HEIGHT, height);
 }
 
 static const struct wlr_drm_format_set *gles2_get_dmabuf_formats(
@@ -376,7 +379,7 @@ static void gles2_destroy(struct wlr_renderer *wlr_renderer) {
 
 	if (renderer->exts.debug_khr) {
 		glDisable(GL_DEBUG_OUTPUT_KHR);
-		glDebugMessageCallbackKHR(NULL, NULL);
+		gles2_procs.glDebugMessageCallbackKHR(NULL, NULL);
 	}
 
 	free(renderer);
@@ -405,19 +408,19 @@ static const struct wlr_renderer_impl renderer_impl = {
 };
 
 void push_gles2_marker(const char *file, const char *func) {
-	if (!glPushDebugGroupKHR) {
+	if (!gles2_procs.glPushDebugGroupKHR) {
 		return;
 	}
 
 	int len = snprintf(NULL, 0, "%s:%s", file, func) + 1;
 	char str[len];
 	snprintf(str, len, "%s:%s", file, func);
-	glPushDebugGroupKHR(GL_DEBUG_SOURCE_APPLICATION_KHR, 1, -1, str);
+	gles2_procs.glPushDebugGroupKHR(GL_DEBUG_SOURCE_APPLICATION_KHR, 1, -1, str);
 }
 
 void pop_gles2_marker(void) {
-	if (glPopDebugGroupKHR) {
-		glPopDebugGroupKHR();
+	if (gles2_procs.glPopDebugGroupKHR) {
+		gles2_procs.glPopDebugGroupKHR();
 	}
 }
 
@@ -516,6 +519,15 @@ static bool check_gl_ext(const char *exts, const char *ext) {
 	return false;
 }
 
+static void load_gl_proc(void *proc_ptr, const char *name) {
+	void *proc = (void *)eglGetProcAddress(name);
+	if (proc == NULL) {
+		wlr_log(WLR_ERROR, "eglGetProcAddress(%s) failed", name);
+		abort();
+	}
+	*(void **)proc_ptr = proc;
+}
+
 extern const GLchar quad_vertex_src[];
 extern const GLchar quad_fragment_src[];
 extern const GLchar ellipse_fragment_src[];
@@ -525,7 +537,9 @@ extern const GLchar tex_fragment_src_rgbx[];
 extern const GLchar tex_fragment_src_external[];
 
 struct wlr_renderer *wlr_gles2_renderer_create(struct wlr_egl *egl) {
-	if (!load_glapi()) {
+	const char *exts_str = (const char *)glGetString(GL_EXTENSIONS);
+	if (exts_str == NULL) {
+		wlr_log(WLR_ERROR, "Failed to get GL_EXTENSIONS");
 		return NULL;
 	}
 
@@ -542,37 +556,44 @@ struct wlr_renderer *wlr_gles2_renderer_create(struct wlr_egl *egl) {
 		return NULL;
 	}
 
-	renderer->exts_str = (const char *)glGetString(GL_EXTENSIONS);
 	wlr_log(WLR_INFO, "Using %s", glGetString(GL_VERSION));
 	wlr_log(WLR_INFO, "GL vendor: %s", glGetString(GL_VENDOR));
 	wlr_log(WLR_INFO, "GL renderer: %s", glGetString(GL_RENDERER));
-	wlr_log(WLR_INFO, "Supported GLES2 extensions: %s", renderer->exts_str);
+	wlr_log(WLR_INFO, "Supported GLES2 extensions: %s", exts_str);
 
-	if (!check_gl_ext(renderer->exts_str, "GL_EXT_texture_format_BGRA8888")) {
+	if (!check_gl_ext(exts_str, "GL_EXT_texture_format_BGRA8888")) {
 		wlr_log(WLR_ERROR, "BGRA8888 format not supported by GLES2");
 		free(renderer);
 		return NULL;
 	}
 
 	renderer->exts.read_format_bgra_ext =
-		check_gl_ext(renderer->exts_str, "GL_EXT_read_format_bgra");
-	renderer->exts.debug_khr =
-		check_gl_ext(renderer->exts_str, "GL_KHR_debug") &&
-		glDebugMessageCallbackKHR && glDebugMessageControlKHR;
-	renderer->exts.egl_image_external_oes =
-		check_gl_ext(renderer->exts_str, "GL_OES_EGL_image_external") &&
-		glEGLImageTargetTexture2DOES;
+		check_gl_ext(exts_str, "GL_EXT_read_format_bgra");
+
+	if (check_gl_ext(exts_str, "GL_KHR_debug")) {
+		renderer->exts.debug_khr = true;
+		load_gl_proc(&gles2_procs.glDebugMessageCallbackKHR,
+			"glDebugMessageCallbackKHR");
+		load_gl_proc(&gles2_procs.glDebugMessageControlKHR,
+			"glDebugMessageControlKHR");
+	}
+
+	if (check_gl_ext(exts_str, "GL_OES_EGL_image_external")) {
+		renderer->exts.egl_image_external_oes = true;
+		load_gl_proc(&gles2_procs.glEGLImageTargetTexture2DOES,
+			"glEGLImageTargetTexture2DOES");
+	}
 
 	if (renderer->exts.debug_khr) {
 		glEnable(GL_DEBUG_OUTPUT_KHR);
 		glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS_KHR);
-		glDebugMessageCallbackKHR(gles2_log, NULL);
+		gles2_procs.glDebugMessageCallbackKHR(gles2_log, NULL);
 
 		// Silence unwanted message types
-		glDebugMessageControlKHR(GL_DONT_CARE, GL_DEBUG_TYPE_POP_GROUP_KHR,
-			GL_DONT_CARE, 0, NULL, GL_FALSE);
-		glDebugMessageControlKHR(GL_DONT_CARE, GL_DEBUG_TYPE_PUSH_GROUP_KHR,
-			GL_DONT_CARE, 0, NULL, GL_FALSE);
+		gles2_procs.glDebugMessageControlKHR(GL_DONT_CARE,
+			GL_DEBUG_TYPE_POP_GROUP_KHR, GL_DONT_CARE, 0, NULL, GL_FALSE);
+		gles2_procs.glDebugMessageControlKHR(GL_DONT_CARE,
+			GL_DEBUG_TYPE_PUSH_GROUP_KHR, GL_DONT_CARE, 0, NULL, GL_FALSE);
 	}
 
 	PUSH_GLES2_DEBUG;
@@ -641,7 +662,7 @@ error:
 
 	if (renderer->exts.debug_khr) {
 		glDisable(GL_DEBUG_OUTPUT_KHR);
-		glDebugMessageCallbackKHR(NULL, NULL);
+		gles2_procs.glDebugMessageCallbackKHR(NULL, NULL);
 	}
 
 	free(renderer);
diff --git a/render/gles2/texture.c b/render/gles2/texture.c
index 9ff88b35..7beb0672 100644
--- a/render/gles2/texture.c
+++ b/render/gles2/texture.c
@@ -11,7 +11,6 @@
 #include <wlr/render/wlr_texture.h>
 #include <wlr/types/wlr_matrix.h>
 #include <wlr/util/log.h>
-#include "glapi.h"
 #include "render/gles2.h"
 #include "util/signal.h"
 
@@ -91,12 +90,12 @@ static bool gles2_texture_to_dmabuf(struct wlr_texture *wlr_texture,
 	if (!texture->image) {
 		assert(texture->target == GL_TEXTURE_2D);
 
-		if (!eglCreateImageKHR) {
+		if (!texture->egl->exts.image_base_khr) {
 			return false;
 		}
 
-		texture->image = eglCreateImageKHR(texture->egl->display,
-			texture->egl->context, EGL_GL_TEXTURE_2D_KHR,
+		texture->image = texture->egl->procs.eglCreateImageKHR(
+			texture->egl->display, texture->egl->context, EGL_GL_TEXTURE_2D_KHR,
 			(EGLClientBuffer)(uintptr_t)texture->tex, NULL);
 		if (texture->image == EGL_NO_IMAGE_KHR) {
 			return false;
@@ -188,7 +187,7 @@ struct wlr_texture *wlr_gles2_texture_from_wl_drm(struct wlr_egl *egl,
 		wlr_egl_make_current(egl, EGL_NO_SURFACE, NULL);
 	}
 
-	if (!glEGLImageTargetTexture2DOES) {
+	if (!gles2_procs.glEGLImageTargetTexture2DOES) {
 		return NULL;
 	}
 
@@ -230,7 +229,8 @@ struct wlr_texture *wlr_gles2_texture_from_wl_drm(struct wlr_egl *egl,
 
 	glGenTextures(1, &texture->tex);
 	glBindTexture(GL_TEXTURE_EXTERNAL_OES, texture->tex);
-	glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES, texture->image);
+	gles2_procs.glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES,
+		texture->image);
 
 	POP_GLES2_DEBUG;
 	return &texture->wlr_texture;
@@ -242,7 +242,7 @@ struct wlr_texture *wlr_gles2_texture_from_dmabuf(struct wlr_egl *egl,
 		wlr_egl_make_current(egl, EGL_NO_SURFACE, NULL);
 	}
 
-	if (!glEGLImageTargetTexture2DOES) {
+	if (!gles2_procs.glEGLImageTargetTexture2DOES) {
 		return NULL;
 	}
 
@@ -290,7 +290,8 @@ struct wlr_texture *wlr_gles2_texture_from_dmabuf(struct wlr_egl *egl,
 
 	glGenTextures(1, &texture->tex);
 	glBindTexture(GL_TEXTURE_EXTERNAL_OES, texture->tex);
-	glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES, texture->image);
+	gles2_procs.glEGLImageTargetTexture2DOES(GL_TEXTURE_EXTERNAL_OES,
+		texture->image);
 
 	POP_GLES2_DEBUG;
 	return &texture->wlr_texture;