From 0ee6f948e183fe0fab022c3841443526f84f52e5 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Sat, 19 Sep 2009 05:12:26 +0000
Subject: [PATCH] Fixed bug #783

Fixed coordinate positioning with OpenGL renderer, and added a test case
---
 src/video/SDL_renderer_gl.c |  4 ++--
 test/testsprite2.c          | 13 +++++++++++--
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/src/video/SDL_renderer_gl.c b/src/video/SDL_renderer_gl.c
index f5329dcde..a92717bd2 100644
--- a/src/video/SDL_renderer_gl.c
+++ b/src/video/SDL_renderer_gl.c
@@ -450,8 +450,8 @@ GL_ActivateRenderer(SDL_Renderer * renderer)
         data->glMatrixMode(GL_MODELVIEW);
         data->glLoadIdentity();
         data->glViewport(0, 0, window->w, window->h);
-        data->glOrtho(0.0, (GLdouble) window->w, (GLdouble) window->h, 0.0,
-                      0.0, 1.0);
+        data->glOrtho(-0.5, (GLdouble) window->w-0.5,
+                      (GLdouble) window->h-0.5, -0.5, 0.0, 1.0);
         data->updateSize = SDL_FALSE;
     }
     return 0;
diff --git a/test/testsprite2.c b/test/testsprite2.c
index cbe70dab1..b502a9caa 100644
--- a/test/testsprite2.c
+++ b/test/testsprite2.c
@@ -134,10 +134,19 @@ MoveSprites(SDL_WindowID window, SDL_TextureID sprite)
         SDL_SetTextureAlphaMod(sprite, (Uint8) current_alpha);
     }
 
-    /* Move the sprite, bounce at the wall, and draw */
-    n = 0;
+    /* Draw a gray background */
     SDL_SetRenderDrawColor(0xA0, 0xA0, 0xA0, 0xFF);
     SDL_RenderFill(NULL);
+
+    /* Draw two red points to make sure they show up correctly */
+    SDL_SetRenderDrawColor(0xFF, 0x00, 0x00, 0xFF);
+    SDL_RenderPoint(0, 0);
+    SDL_RenderPoint(window_w-1, 0);
+    SDL_RenderPoint(0, window_h-1);
+    SDL_RenderPoint(window_w-1, window_h-1);
+
+    /* Move the sprite, bounce at the wall, and draw */
+    n = 0;
     for (i = 0; i < num_sprites; ++i) {
         position = &positions[i];
         velocity = &velocities[i];