Add support for OpenGL ES 3.2 in pugl_shader_demo

9 files changed, 65 insertions, 38 deletions

diff --git a/examples/pugl_shader_demo.app/Resources/meson.build b/examples/pugl_shader_demo.app/Resources/meson.build
index ddbdcbe..7659daa 100644
--- a/examples/pugl_shader_demo.app/Resources/meson.build
+++ b/examples/pugl_shader_demo.app/Resources/meson.build
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: 0BSD OR ISC
 
 shaders = [
+  'header_320_es.glsl',
   'header_330.glsl',
   'header_420.glsl',
   'rect.vert',
diff --git a/examples/pugl_shader_demo.app/meson.build b/examples/pugl_shader_demo.app/meson.build
index 6885920..d7347b5 100644
--- a/examples/pugl_shader_demo.app/meson.build
+++ b/examples/pugl_shader_demo.app/meson.build
@@ -9,6 +9,7 @@ info_plist = configure_file(configuration: config,
                             output: 'Info.plist')
 
 shaders = [
+  'header_320_es.glsl',
   'header_330.glsl',
   'header_420.glsl',
   'rect.vert',
diff --git a/examples/pugl_shader_demo.c b/examples/pugl_shader_demo.c
index f273e31..02290da 100644
--- a/examples/pugl_shader_demo.c
+++ b/examples/pugl_shader_demo.c
@@ -63,8 +63,6 @@ typedef struct {
   double          lastDrawDuration;
   double          lastFrameEndTime;
   unsigned        framesDrawn;
-  int             glMajorVersion;
-  int             glMinorVersion;
   int             quit;
 } PuglTestApp;
 
@@ -235,22 +233,6 @@ parseOptions(PuglTestApp* app, int argc, char** argv)
     }
   }
 
-  // Parse OpenGL major version argument, if given
-  if (argc >= 2) {
-    app->glMajorVersion = (int)strtol(argv[1], &endptr, 10);
-    if (endptr != argv[1] + strlen(argv[1])) {
-      logError("Invalid GL major version: %s\n", argv[1]);
-      return 1;
-    }
-
-    if (app->glMajorVersion == 4) {
-      app->glMinorVersion = 2;
-    } else if (app->glMajorVersion != 3) {
-      logError("Unsupported GL major version %d\n", app->glMajorVersion);
-      return 1;
-    }
-  }
-
   return 0;
 }
 
@@ -271,9 +253,11 @@ setupPugl(PuglTestApp* app)
   puglSetSizeHint(app->view, PUGL_MIN_ASPECT, 1, 1);
   puglSetSizeHint(app->view, PUGL_MAX_ASPECT, 16, 9);
   puglSetBackend(app->view, puglGlBackend());
-  puglSetViewHint(app->view, PUGL_CONTEXT_API, PUGL_OPENGL_API);
-  puglSetViewHint(app->view, PUGL_CONTEXT_VERSION_MAJOR, app->glMajorVersion);
-  puglSetViewHint(app->view, PUGL_CONTEXT_VERSION_MINOR, app->glMinorVersion);
+  puglSetViewHint(app->view, PUGL_CONTEXT_API, app->opts.glApi);
+  puglSetViewHint(
+    app->view, PUGL_CONTEXT_VERSION_MAJOR, app->opts.glMajorVersion);
+  puglSetViewHint(
+    app->view, PUGL_CONTEXT_VERSION_MINOR, app->opts.glMinorVersion);
   puglSetViewHint(app->view, PUGL_CONTEXT_PROFILE, PUGL_OPENGL_CORE_PROFILE);
   puglSetViewHint(app->view, PUGL_CONTEXT_DEBUG, app->opts.errorChecking);
   puglSetViewHint(app->view, PUGL_RESIZABLE, app->opts.resizable);
@@ -288,15 +272,41 @@ setupPugl(PuglTestApp* app)
 static PuglStatus
 setupGl(PuglTestApp* app)
 {
-  // Load GL functions via GLAD
-  if (!gladLoadGLLoader((GLADloadproc)&puglGetProcAddress)) {
-    logError("Failed to load GL\n");
+  // Load GL and determine the shader header to load
+  const char* headerFile = NULL;
+  if (app->opts.glApi == PUGL_OPENGL_API) {
+    if (!gladLoadGLLoader((GLADloadproc)&puglGetProcAddress)) {
+      logError("Failed to load OpenGL\n");
+      return PUGL_FAILURE;
+    }
+
+    headerFile =
+      (app->opts.glMajorVersion == 3 && app->opts.glMinorVersion == 3)
+        ? (SHADER_DIR "header_330.glsl")
+      : (app->opts.glMajorVersion == 4 && app->opts.glMinorVersion == 2)
+        ? (SHADER_DIR "header_420.glsl")
+        : NULL;
+
+  } else if (app->opts.glApi == PUGL_OPENGL_ES_API) {
+    if (!gladLoadGLES2Loader((GLADloadproc)&puglGetProcAddress)) {
+      logError("Failed to load OpenGL ES\n");
+      return PUGL_FAILURE;
+    }
+
+    headerFile =
+      (app->opts.glMajorVersion == 3 && app->opts.glMinorVersion == 2)
+        ? (SHADER_DIR "header_320_es.glsl")
+        : NULL;
+
+  } else {
+    logError("Unsupported API\n");
     return PUGL_FAILURE;
   }
 
-  const char* const headerFile =
-    (app->glMajorVersion == 3 ? SHADER_DIR "header_330.glsl"
-                              : SHADER_DIR "header_420.glsl");
+  if (!headerFile) {
+    logError("Unsupported OpenGL version\n");
+    return PUGL_FAILURE;
+  }
 
   // Load shader sources
   char* const headerSource = loadShader(app->programPath, headerFile);
@@ -433,9 +443,9 @@ main(int argc, char** argv)
 {
   PuglTestApp app = {0};
 
-  app.programPath    = argv[0];
-  app.glMajorVersion = 3;
-  app.glMinorVersion = 3;
+  app.programPath         = argv[0];
+  app.opts.glMajorVersion = 3;
+  app.opts.glMinorVersion = 3;
 
   // Parse command line options
   if (parseOptions(&app, argc, argv)) {
diff --git a/examples/shaders/header_320_es.glsl b/examples/shaders/header_320_es.glsl
new file mode 100644
index 0000000..ce5fe68
--- /dev/null
+++ b/examples/shaders/header_320_es.glsl
@@ -0,0 +1,8 @@
+// Copyright 2020-2023 David Robillard <d@drobilla.net>
+// SPDX-License-Identifier: ISC
+
+#version 320 es
+
+#define NOPERSPECTIVE
+#define INTER(qualifiers)
+#define UBO(qualifiers) layout(std140)
diff --git a/examples/shaders/header_330.glsl b/examples/shaders/header_330.glsl
index 1de3301..11bdc53 100644
--- a/examples/shaders/header_330.glsl
+++ b/examples/shaders/header_330.glsl
@@ -1,7 +1,8 @@
-// Copyright 2020 David Robillard <d@drobilla.net>
+// Copyright 2020-2023 David Robillard <d@drobilla.net>
 // SPDX-License-Identifier: ISC
 
 #version 330 core
 
+#define NOPERSPECTIVE
 #define INTER(qualifiers)
 #define UBO(qualifiers) layout(std140)
diff --git a/examples/shaders/header_420.glsl b/examples/shaders/header_420.glsl
index 95fe1a1..cd226c9 100644
--- a/examples/shaders/header_420.glsl
+++ b/examples/shaders/header_420.glsl
@@ -1,7 +1,8 @@
-// Copyright 2020 David Robillard <d@drobilla.net>
+// Copyright 2020-2023 David Robillard <d@drobilla.net>
 // SPDX-License-Identifier: ISC
 
 #version 420 core
 
+#define NOPERSPECTIVE noperspective
 #define INTER(qualifiers) layout(qualifiers)
 #define UBO(qualifiers) layout(std140, qualifiers)
diff --git a/examples/shaders/meson.build b/examples/shaders/meson.build
index 54e9235..479f162 100644
--- a/examples/shaders/meson.build
+++ b/examples/shaders/meson.build
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: 0BSD OR ISC
 
 shader_files = [
+  'header_320_es.glsl',
   'header_330.glsl',
   'header_420.glsl',
   'rect.frag',
diff --git a/examples/shaders/rect.frag b/examples/shaders/rect.frag
index 9cee53b..17290bd 100644
--- a/examples/shaders/rect.frag
+++ b/examples/shaders/rect.frag
@@ -11,9 +11,11 @@
    specified precisely in pixels to draw sharp lines.  The border width is just
    hardcoded, but could be made a uniform or vertex attribute easily enough. */
 
-INTER(location = 0) noperspective in vec2 f_uv;
-INTER(location = 1) noperspective in vec2 f_size;
-INTER(location = 2) noperspective in vec4 f_fillColor;
+precision mediump float;
+
+INTER(location = 0) NOPERSPECTIVE in vec2 f_uv;
+INTER(location = 1) NOPERSPECTIVE in vec2 f_size;
+INTER(location = 2) NOPERSPECTIVE in vec4 f_fillColor;
 
 layout(location = 0) out vec4 FragColor;
 
diff --git a/examples/shaders/rect.vert b/examples/shaders/rect.vert
index 0fa4dbc..ebdbec5 100644
--- a/examples/shaders/rect.vert
+++ b/examples/shaders/rect.vert
@@ -4,6 +4,8 @@
 /* The vertex shader is trivial, but forwards scaled UV coordinates (in pixels)
    to the fragment shader for drawing the border. */
 
+precision mediump float;
+
 UBO(binding = 0) uniform UniformBufferObject
 {
   mat4 projection;
@@ -15,9 +17,9 @@ layout(location = 1) in vec2 v_origin;
 layout(location = 2) in vec2 v_size;
 layout(location = 3) in vec4 v_fillColor;
 
-INTER(location = 0) noperspective out vec2 f_uv;
-INTER(location = 1) noperspective out vec2 f_size;
-INTER(location = 2) noperspective out vec4 f_fillColor;
+INTER(location = 0) NOPERSPECTIVE out vec2 f_uv;
+INTER(location = 1) NOPERSPECTIVE out vec2 f_size;
+INTER(location = 2) NOPERSPECTIVE out vec4 f_fillColor;
 
 void
 main()