From b5c7989e9b5a801df6c65004b9fcaeb19e99826a Mon Sep 17 00:00:00 2001
From: Paul Duncan <pabs@pablotron.org>
Date: Mon, 25 Jun 2018 17:34:42 -0400
Subject: fix gpu timings

---
 ops.yaml | 33 ++++++++++++++++++---------------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/ops.yaml b/ops.yaml
index eac671c..5cf9c77 100644
--- a/ops.yaml
+++ b/ops.yaml
@@ -10139,7 +10139,7 @@ templates:
     }
 
     static void
-    gpu_draw(
+    gpu_draw_line(
       gb_t * const ctx
     ) {
       struct {
@@ -10238,26 +10238,28 @@ templates:
 
       switch (gpu_get_mode(ctx)) {
       case GPU_MODE_OAM:
-        if (ctx->gpu.clock > 79) {
+        if (ctx->gpu.clock >= 80) {
           // clear clock, set mode
-          ctx->gpu.clock = 0;
+          ctx->gpu.clock -= 80;
           gpu_set_mode(ctx, GPU_MODE_VRAM);
         }
 
         break;
       case GPU_MODE_VRAM:
-        if (ctx->gpu.clock > 171) {
+        if (ctx->gpu.clock >= 172) {
           // clear clock, set mode
-          ctx->gpu.clock = 0;
+          ctx->gpu.clock -= 172;
           gpu_set_mode(ctx, GPU_MODE_HBLANK);
         }
 
         break;
       case GPU_MODE_HBLANK:
-        if (ctx->gpu.clock > 203) {
+        if (ctx->gpu.clock >= 204) {
           // clear clock, draw line, increment line
-          ctx->gpu.clock = 0;
-          gpu_draw(ctx);
+          ctx->gpu.clock -= 204;
+
+          // draw and increment line
+          gpu_draw_line(ctx);
           gpu_set_line(ctx, ctx->gpu.line + 1);
 
           if (ctx->gpu.line < 144) {
@@ -10274,14 +10276,15 @@ templates:
 
         break;
       case GPU_MODE_VBLANK:
-        if (ctx->gpu.clock > 204) {
-          // clear clock, increment line
-          ctx->gpu.clock = 0;
-          gpu_set_line(ctx, ctx->gpu.line + 1);
+        if (ctx->gpu.clock >= 204) {
+          // clear clock
+          ctx->gpu.clock -= 204;
 
-          if (ctx->gpu.line > 153) {
-            // reset clock, reset line, set mode
-            ctx->gpu.clock = 0;
+          if (ctx->gpu.line < 154) {
+            // increment line
+            gpu_set_line(ctx, ctx->gpu.line + 1);
+          } else {
+            // reset line, set mode
             gpu_set_line(ctx, 0);
             gpu_set_mode(ctx, GPU_MODE_OAM);
           }
-- 
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