From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Wed, 2 Sep 2015 21:52:47 +0000 (+0200)
Subject: Draw an oversized triangle instead of a quad.
X-Git-Tag: 1.2.0~31
X-Git-Url: https://git.sesse.net/?a=commitdiff_plain;h=dffda797f940519873d07fe942017c0dafea2342;hp=4a35c01ed5407a3d9b9616f9d13e77970ee003ef;p=movit

Draw an oversized triangle instead of a quad.

This is mostly theoretical; I've never been able to measure any
sort of real change from this. But according to popular cargo-culting,
it might have an effect since there are fewer edge pixels to shade.
---

diff --git a/effect_chain.cpp b/effect_chain.cpp
index 870da81..048cc1e 100644
--- a/effect_chain.cpp
+++ b/effect_chain.cpp
@@ -1607,10 +1607,9 @@ void EffectChain::execute_phase(Phase *phase, bool last_phase, map<Phase *, GLui
 
 	// Now draw!
 	float vertices[] = {
-		0.0f, 1.0f,
+		0.0f, 2.0f,
 		0.0f, 0.0f,
-		1.0f, 1.0f,
-		1.0f, 0.0f
+		2.0f, 0.0f
 	};
 
 	GLuint vao;
@@ -1622,7 +1621,7 @@ void EffectChain::execute_phase(Phase *phase, bool last_phase, map<Phase *, GLui
 	GLuint position_vbo = fill_vertex_attribute(glsl_program_num, "position", 2, GL_FLOAT, sizeof(vertices), vertices);
 	GLuint texcoord_vbo = fill_vertex_attribute(glsl_program_num, "texcoord", 2, GL_FLOAT, sizeof(vertices), vertices);  // Same as vertices.
 
-	glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+	glDrawArrays(GL_TRIANGLES, 0, 3);
 	check_error();
 
 	cleanup_vertex_attribute(glsl_program_num, "position", position_vbo);