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Added comment for pixel-perfect line workaround.
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slouken committed Nov 21, 2009
1 parent 072f612 commit bfffff5
Showing 1 changed file with 5 additions and 1 deletion.
6 changes: 5 additions & 1 deletion src/video/SDL_renderer_gl.c
Expand Up @@ -1157,13 +1157,17 @@ GL_RenderLine(SDL_Renderer * renderer, int x1, int y1, int x2, int y2)

/* The line is half open, so we need one more point to complete the line.
* http://www.opengl.org/documentation/specs/version1.1/glspec1.1/node47.html
* If we have to, we can use vertical line and horizontal line textures
* for vertical and horizontal lines, and then create custom textures
* for diagonal lines and software render those. It's terrible, but at
* least it would be pixel perfect.
*/
data->glBegin(GL_POINTS);
#ifdef __APPLE__
/* Mac OS X seems to always leave the second point open */
data->glVertex2f(0.5f + x2, 0.5f + y2);
#else
/* Linux seems to use the right-most or bottom-most point open */
/* Linux seems to leave the right-most or bottom-most point open */
if (x1 > x2) {
data->glVertex2f(0.5f + x1, 0.5f + y1);
} else if (x2 > x1) {
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