From 23f3b99003da63c275771b295d6b9069fc56205e Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Thu, 19 Nov 2015 21:17:57 +0100
Subject: vo_opengl: create FBOs in a more GLES conformant way

While desktop GL's glTexImage2D() essentially accepts anything, GLES is
much stricter. The combination of allowed formats/types/internal formats
is exactly specified. The GLES 3.0.4 specification lists them in
table 3.2. (The ANGLE API validation code references this table.)

The table could probably be extended into a general declarative table
about GL formats covering other uses, but this would be a big
non-trivial project, so don't bother and accept a minor degree
of duplication with other tables.

Note that the format and type do (or should) not matter here, because
no image data is transferred to the GPU.
---
 video/out/opengl/utils.c | 42 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 40 insertions(+), 2 deletions(-)

(limited to 'video')

diff --git a/video/out/opengl/utils.c b/video/out/opengl/utils.c
index 83bed06498..cdd549a791 100644
--- a/video/out/opengl/utils.c
+++ b/video/out/opengl/utils.c
@@ -312,6 +312,32 @@ void gl_vao_draw_data(struct gl_vao *vao, GLenum prim, void *ptr, size_t num)
     gl_vao_unbind(vao);
 }
 
+struct gl_format {
+    GLenum format;
+    GLenum type;
+    GLint internal_format;
+};
+
+static const struct gl_format gl_formats[] = {
+    // GLES 3.0
+    {GL_RGB,    GL_UNSIGNED_BYTE,               GL_RGB},
+    {GL_RGBA,   GL_UNSIGNED_BYTE,               GL_RGBA},
+    {GL_RGB,    GL_UNSIGNED_BYTE,               GL_RGB8},
+    {GL_RGBA,   GL_UNSIGNED_BYTE,               GL_RGBA8},
+    {GL_RGB,    GL_UNSIGNED_SHORT,              GL_RGB16},
+    {GL_RGBA,   GL_UNSIGNED_INT_2_10_10_10_REV, GL_RGB10_A2},
+    // not texture filterable in GLES 3.0
+    {GL_RGB,    GL_FLOAT,                       GL_RGB16F},
+    {GL_RGBA,   GL_FLOAT,                       GL_RGBA16F},
+    {GL_RGB,    GL_FLOAT,                       GL_RGB32F},
+    {GL_RGBA,   GL_FLOAT,                       GL_RGBA32F},
+    // Desktop GL
+    {GL_RGB,    GL_UNSIGNED_SHORT,              GL_RGB10},
+    {GL_RGBA,   GL_UNSIGNED_SHORT,              GL_RGBA12},
+    {GL_RGBA,   GL_UNSIGNED_SHORT,              GL_RGBA16},
+    {0}
+};
+
 // Create a texture and a FBO using the texture as color attachments.
 //  iformat: texture internal format
 // Returns success.
@@ -349,6 +375,18 @@ bool fbotex_change(struct fbotex *fbo, GL *gl, struct mp_log *log, int w, int h,
 
     GLenum filter = fbo->tex_filter;
 
+    struct gl_format format = {
+        .format = GL_RGBA,
+        .type = GL_UNSIGNED_BYTE,
+        .internal_format = iformat,
+    };
+    for (int n = 0; gl_formats[n].format; n++) {
+        if (gl_formats[n].internal_format == format.internal_format) {
+            format = gl_formats[n];
+            break;
+        }
+    }
+
     *fbo = (struct fbotex) {
         .gl = gl,
         .w = w,
@@ -364,8 +402,8 @@ bool fbotex_change(struct fbotex *fbo, GL *gl, struct mp_log *log, int w, int h,
     gl->GenFramebuffers(1, &fbo->fbo);
     gl->GenTextures(1, &fbo->texture);
     gl->BindTexture(GL_TEXTURE_2D, fbo->texture);
-    gl->TexImage2D(GL_TEXTURE_2D, 0, iformat, fbo->w, fbo->h, 0,
-                   GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+    gl->TexImage2D(GL_TEXTURE_2D, 0, format.internal_format, fbo->w, fbo->h, 0,
+                   format.format, format.type, NULL);
     gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     gl->TexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     gl->BindTexture(GL_TEXTURE_2D, 0);
-- 
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