From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sun, 19 Jan 2014 19:42:22 +0000 (+0100)
Subject: Store GL_FLOAT FlatInputs as fp32, not fp16.
X-Git-Tag: 1.0~79
X-Git-Url: https://git.sesse.net/?p=movit;a=commitdiff_plain;h=68fd0c4ec98ed00d3ddeb87cfd809372a8b01e4b;hp=a9bd8dc1e30b82bc99a445f80df09488b4f9d1f4

Store GL_FLOAT FlatInputs as fp32, not fp16.

There are two primary reasons for this:

 - GL_FLOAT FlatInput is primarily used for tests, and even more importantly,
   mostly accuracy tests. ATI's drivers appear to round off fp32 -> fp16
   wrong (truncate instead of round), which breaks some of these tests.
 - In case someone _would_ use GL_FLOAT inputs, they'd probably be updated
   every frame anyway, so the fp32 -> fp16 conversion step (probably on CPU)
   will negate any performance benefits by fp16 sampling anyway.
---

diff --git a/flat_input.cpp b/flat_input.cpp
index 28380f4..cf53034 100644
--- a/flat_input.cpp
+++ b/flat_input.cpp
@@ -39,7 +39,7 @@ void FlatInput::finalize()
 	// Translate the input format to OpenGL's enums.
 	GLenum internal_format;
 	if (type == GL_FLOAT) {
-		internal_format = GL_RGBA16F_ARB;
+		internal_format = GL_RGBA32F_ARB;
 	} else if (output_linear_gamma) {
 		assert(type == GL_UNSIGNED_BYTE);
 		internal_format = GL_SRGB8_ALPHA8;