From 0d014a542a28ce57b7a8ea9056258ca017f158d1 Mon Sep 17 00:00:00 2001
From: SlyVTT <pillot.sylvain@gmail.com>
Date: Sun, 7 May 2023 16:08:29 +0200
Subject: [PATCH] added a working line shader

---
 azur/src/gint/shaders/line.c | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/azur/src/gint/shaders/line.c b/azur/src/gint/shaders/line.c
index 788086b..e468e97 100644
--- a/azur/src/gint/shaders/line.c
+++ b/azur/src/gint/shaders/line.c
@@ -44,7 +44,7 @@ int ABS( int x1 )
 int SGN( int x1 )
 {
     if (x1 > 0) return 1;
-    else if (x1 = 0) return 0;
+    else if (x1 == 0) return 0;
     else return -1;
 }
 
@@ -90,7 +90,7 @@ void azrp_line(int xA, int yA, int xB, int yB, int color)
     cmd.dy = ABS(y2-y1);
     cmd.sy = SGN(y2-y1);
 
-    cmd.i = 1;
+    cmd.i = 0;
     cmd.cumul = (cmd.dx >= cmd.dy) ? cmd.dx >> 1 : cmd.dy >> 1;
 
     azrp_queue_command(&cmd, sizeof cmd, frag_first, frag_count);
@@ -108,15 +108,27 @@ void azrp_shader_line( void *uniforms, void *comnd, void *fragment )
 
     if (cmd->dy == 0)
     {
-        for( i = cmd->i; i < cmd->dx-1 ; i++ )
+        for( i = cmd->i; i < cmd->dx ; i++ )
         {
             cmd->curr_x += cmd->sx;
             frag[ azrp_width * cmd->curr_y + cmd->curr_x ] = cmd->color;
         }
     }
+    else if (cmd->dx == 0)
+    {
+        for( i = cmd->i; i < cmd->dy ; i++ )
+        {
+            cmd->curr_y += cmd->sy;
+            
+            // if curr_y=16, this means we are changing to next fragment
+            if (cmd->curr_y == azrp_frag_height) break;
+            
+            frag[ azrp_width * cmd->curr_y + cmd->curr_x ] = cmd->color;
+        }
+    }
     else if (cmd->dx >= cmd->dy)
     {
-        for( i = cmd->i; i < cmd->dx-1; i++ )
+        for( i = cmd->i; i < cmd->dx; i++ )
         {
             cmd->curr_x += cmd->sx;
             cmd->cumul += cmd->dy;
@@ -133,7 +145,7 @@ void azrp_shader_line( void *uniforms, void *comnd, void *fragment )
     }
     else
     {
-        for( i = cmd->i; i < cmd->dy-1; i++ )
+        for( i = cmd->i; i < cmd->dy; i++ )
         {
             cmd->curr_y += cmd->sy;
             cmd->cumul += cmd->dx;
@@ -150,7 +162,7 @@ void azrp_shader_line( void *uniforms, void *comnd, void *fragment )
         }
     }
 
-    cmd->curr_y &= 15;
+    cmd->curr_y = cmd->curr_y & 15;
 
-    cmd->i = i;
+    cmd->i = i+1;
 }
\ No newline at end of file