render/gles2: move shaders to individual files

Instead of having a C file with strings for each shader, move each
shader into its own file. Use a small POSIX shell script to convert
the files into C strings (can't wait for C23 #embed...).

The benefits from this are:

- Improved readability and syntax highlighting.
- Line numbers in shader compiler errors are easier to make sense of.
- Consistency with the Vulkan renderer.
- Shaders will become more complicated as we add color management
  features.

12 files changed, 102 insertions, 82 deletions

diff --git a/meson.build b/meson.build
index a180b43c..45eeabaa 100644
--- a/meson.build
+++ b/meson.build
@@ -3,7 +3,7 @@ project(
 	'c',
 	version: '0.16.0-dev',
 	license: 'MIT',
-	meson_version: '>=0.58.1',
+	meson_version: '>=0.59.0',
 	default_options: [
 		'c_std=c11',
 		'warning_level=2',
diff --git a/render/gles2/meson.build b/render/gles2/meson.build
index 504f0c11..c9226983 100644
--- a/render/gles2/meson.build
+++ b/render/gles2/meson.build
@@ -10,6 +10,7 @@ wlr_deps += glesv2
 wlr_files += files(
 	'pixel_format.c',
 	'renderer.c',
-	'shaders.c',
 	'texture.c',
 )
+
+subdir('shaders')
diff --git a/render/gles2/renderer.c b/render/gles2/renderer.c
index aa1adabe..de80a55f 100644
--- a/render/gles2/renderer.c
+++ b/render/gles2/renderer.c
@@ -19,6 +19,13 @@
 #include "render/pixel_format.h"
 #include "types/wlr_matrix.h"
 
+#include "quad_vert_src.h"
+#include "quad_frag_src.h"
+#include "tex_vert_src.h"
+#include "tex_rgba_frag_src.h"
+#include "tex_rgbx_frag_src.h"
+#include "tex_external_frag_src.h"
+
 static const GLfloat verts[] = {
 	1, 0, // top right
 	0, 0, // top left
@@ -667,13 +674,6 @@ static void load_gl_proc(void *proc_ptr, const char *name) {
 	*(void **)proc_ptr = proc;
 }
 
-extern const GLchar quad_vertex_src[];
-extern const GLchar quad_fragment_src[];
-extern const GLchar tex_vertex_src[];
-extern const GLchar tex_fragment_src_rgba[];
-extern const GLchar tex_fragment_src_rgbx[];
-extern const GLchar tex_fragment_src_external[];
-
 struct wlr_renderer *wlr_gles2_renderer_create_with_drm_fd(int drm_fd) {
 	struct wlr_egl *egl = wlr_egl_create_with_drm_fd(drm_fd);
 	if (egl == NULL) {
@@ -786,7 +786,7 @@ struct wlr_renderer *wlr_gles2_renderer_create(struct wlr_egl *egl) {
 
 	GLuint prog;
 	renderer->shaders.quad.program = prog =
-		link_program(renderer, quad_vertex_src, quad_fragment_src);
+		link_program(renderer, quad_vert_src, quad_frag_src);
 	if (!renderer->shaders.quad.program) {
 		goto error;
 	}
@@ -795,7 +795,7 @@ struct wlr_renderer *wlr_gles2_renderer_create(struct wlr_egl *egl) {
 	renderer->shaders.quad.pos_attrib = glGetAttribLocation(prog, "pos");
 
 	renderer->shaders.tex_rgba.program = prog =
-		link_program(renderer, tex_vertex_src, tex_fragment_src_rgba);
+		link_program(renderer, tex_vert_src, tex_rgba_frag_src);
 	if (!renderer->shaders.tex_rgba.program) {
 		goto error;
 	}
@@ -806,7 +806,7 @@ struct wlr_renderer *wlr_gles2_renderer_create(struct wlr_egl *egl) {
 	renderer->shaders.tex_rgba.tex_attrib = glGetAttribLocation(prog, "texcoord");
 
 	renderer->shaders.tex_rgbx.program = prog =
-		link_program(renderer, tex_vertex_src, tex_fragment_src_rgbx);
+		link_program(renderer, tex_vert_src, tex_rgbx_frag_src);
 	if (!renderer->shaders.tex_rgbx.program) {
 		goto error;
 	}
@@ -818,7 +818,7 @@ struct wlr_renderer *wlr_gles2_renderer_create(struct wlr_egl *egl) {
 
 	if (renderer->exts.OES_egl_image_external) {
 		renderer->shaders.tex_ext.program = prog =
-			link_program(renderer, tex_vertex_src, tex_fragment_src_external);
+			link_program(renderer, tex_vert_src, tex_external_frag_src);
 		if (!renderer->shaders.tex_ext.program) {
 			goto error;
 		}
diff --git a/render/gles2/shaders.c b/render/gles2/shaders.c
deleted file mode 100644
index 7898059e..00000000
--- a/render/gles2/shaders.c
+++ /dev/null
@@ -1,69 +0,0 @@
-#include <GLES2/gl2.h>
-#include "render/gles2.h"
-
-// Colored quads
-const GLchar quad_vertex_src[] =
-"uniform mat3 proj;\n"
-"uniform vec4 color;\n"
-"attribute vec2 pos;\n"
-"attribute vec2 texcoord;\n"
-"varying vec4 v_color;\n"
-"varying vec2 v_texcoord;\n"
-"\n"
-"void main() {\n"
-"	gl_Position = vec4(proj * vec3(pos, 1.0), 1.0);\n"
-"	v_color = color;\n"
-"	v_texcoord = texcoord;\n"
-"}\n";
-
-const GLchar quad_fragment_src[] =
-"precision mediump float;\n"
-"varying vec4 v_color;\n"
-"varying vec2 v_texcoord;\n"
-"\n"
-"void main() {\n"
-"	gl_FragColor = v_color;\n"
-"}\n";
-
-// Textured quads
-const GLchar tex_vertex_src[] =
-"uniform mat3 proj;\n"
-"attribute vec2 pos;\n"
-"attribute vec2 texcoord;\n"
-"varying vec2 v_texcoord;\n"
-"\n"
-"void main() {\n"
-"	gl_Position = vec4(proj * vec3(pos, 1.0), 1.0);\n"
-"	v_texcoord = texcoord;\n"
-"}\n";
-
-const GLchar tex_fragment_src_rgba[] =
-"precision mediump float;\n"
-"varying vec2 v_texcoord;\n"
-"uniform sampler2D tex;\n"
-"uniform float alpha;\n"
-"\n"
-"void main() {\n"
-"	gl_FragColor = texture2D(tex, v_texcoord) * alpha;\n"
-"}\n";
-
-const GLchar tex_fragment_src_rgbx[] =
-"precision mediump float;\n"
-"varying vec2 v_texcoord;\n"
-"uniform sampler2D tex;\n"
-"uniform float alpha;\n"
-"\n"
-"void main() {\n"
-"	gl_FragColor = vec4(texture2D(tex, v_texcoord).rgb, 1.0) * alpha;\n"
-"}\n";
-
-const GLchar tex_fragment_src_external[] =
-"#extension GL_OES_EGL_image_external : require\n\n"
-"precision mediump float;\n"
-"varying vec2 v_texcoord;\n"
-"uniform samplerExternalOES texture0;\n"
-"uniform float alpha;\n"
-"\n"
-"void main() {\n"
-"	gl_FragColor = texture2D(texture0, v_texcoord) * alpha;\n"
-"}\n";
diff --git a/render/gles2/shaders/embed.sh b/render/gles2/shaders/embed.sh
new file mode 100755
index 00000000..acd7a119
--- /dev/null
+++ b/render/gles2/shaders/embed.sh
@@ -0,0 +1,11 @@
+#!/bin/sh -eu
+
+var=${1:-data}
+hex="$(od -A n -t x1 -v)"
+
+echo "static const char $var[] = {"
+for byte in $hex; do
+	echo "	0x$byte,"
+done
+echo "	0x00,"
+echo "};"
diff --git a/render/gles2/shaders/meson.build b/render/gles2/shaders/meson.build
new file mode 100644
index 00000000..626c2b14
--- /dev/null
+++ b/render/gles2/shaders/meson.build
@@ -0,0 +1,23 @@
+embed = find_program('./embed.sh', native: true)
+
+shaders = [
+	'quad.vert',
+	'quad.frag',
+	'tex.vert',
+	'tex_rgba.frag',
+	'tex_rgbx.frag',
+	'tex_external.frag',
+]
+
+foreach name : shaders
+	output = name.underscorify() + '_src.h'
+	var = name.underscorify() + '_src'
+	wlr_files += custom_target(
+		output,
+		command: [embed, var],
+		input: name,
+		output: output,
+		feed: true,
+		capture: true,
+	)
+endforeach
diff --git a/render/gles2/shaders/quad.frag b/render/gles2/shaders/quad.frag
new file mode 100644
index 00000000..08291046
--- /dev/null
+++ b/render/gles2/shaders/quad.frag
@@ -0,0 +1,7 @@
+precision mediump float;
+varying vec4 v_color;
+varying vec2 v_texcoord;
+
+void main() {
+	gl_FragColor = v_color;
+}
diff --git a/render/gles2/shaders/quad.vert b/render/gles2/shaders/quad.vert
new file mode 100644
index 00000000..abcafd07
--- /dev/null
+++ b/render/gles2/shaders/quad.vert
@@ -0,0 +1,12 @@
+uniform mat3 proj;
+uniform vec4 color;
+attribute vec2 pos;
+attribute vec2 texcoord;
+varying vec4 v_color;
+varying vec2 v_texcoord;
+
+void main() {
+	gl_Position = vec4(proj * vec3(pos, 1.0), 1.0);
+	v_color = color;
+	v_texcoord = texcoord;
+}
diff --git a/render/gles2/shaders/tex.vert b/render/gles2/shaders/tex.vert
new file mode 100644
index 00000000..9cebb458
--- /dev/null
+++ b/render/gles2/shaders/tex.vert
@@ -0,0 +1,9 @@
+uniform mat3 proj;
+attribute vec2 pos;
+attribute vec2 texcoord;
+varying vec2 v_texcoord;
+
+void main() {
+	gl_Position = vec4(proj * vec3(pos, 1.0), 1.0);
+	v_texcoord = texcoord;
+}
diff --git a/render/gles2/shaders/tex_external.frag b/render/gles2/shaders/tex_external.frag
new file mode 100644
index 00000000..05eac503
--- /dev/null
+++ b/render/gles2/shaders/tex_external.frag
@@ -0,0 +1,10 @@
+#extension GL_OES_EGL_image_external : require
+
+precision mediump float;
+varying vec2 v_texcoord;
+uniform samplerExternalOES texture0;
+uniform float alpha;
+
+void main() {
+	gl_FragColor = texture2D(texture0, v_texcoord) * alpha;
+}
diff --git a/render/gles2/shaders/tex_rgba.frag b/render/gles2/shaders/tex_rgba.frag
new file mode 100644
index 00000000..c2e17a90
--- /dev/null
+++ b/render/gles2/shaders/tex_rgba.frag
@@ -0,0 +1,8 @@
+precision mediump float;
+varying vec2 v_texcoord;
+uniform sampler2D tex;
+uniform float alpha;
+
+void main() {
+	gl_FragColor = texture2D(tex, v_texcoord) * alpha;
+}
diff --git a/render/gles2/shaders/tex_rgbx.frag b/render/gles2/shaders/tex_rgbx.frag
new file mode 100644
index 00000000..42ddf92f
--- /dev/null
+++ b/render/gles2/shaders/tex_rgbx.frag
@@ -0,0 +1,8 @@
+precision mediump float;
+varying vec2 v_texcoord;
+uniform sampler2D tex;
+uniform float alpha;
+
+void main() {
+	gl_FragColor = vec4(texture2D(tex, v_texcoord).rgb, 1.0) * alpha;
+}