From 600df042f89ab4d3ce72b84c83ca4134d69f67bf Mon Sep 17 00:00:00 2001
From: Mitya Selivanov <automainint@guattari.tech>
Date: Thu, 23 Jan 2025 13:23:23 +0100
Subject: Cleanup

---
 graphics.c | 91 ++++++++++++++++++++++++++++----------------------------------
 1 file changed, 41 insertions(+), 50 deletions(-)

(limited to 'graphics.c')

diff --git a/graphics.c b/graphics.c
index ec1e243..49a7e04 100755
--- a/graphics.c
+++ b/graphics.c
@@ -41,6 +41,7 @@ exit $? # */
 #define REDUCED_SYSTEM_LAYER_HEADER
 #endif
 
+#define NO_WAYLAND 1
 #include "reduced_system_layer.c"
 
 //  ================================================================
@@ -217,6 +218,10 @@ enum {
   CHAR_NUM_BITS_   = CHAR_NUM_BITS_X_ * CHAR_NUM_BITS_Y_,
 };
 
+static f32 max2_f32_(f32 a, f32 b) {
+  return a < b ? b : a;
+}
+
 static f64 min3_(f64 a, f64 b, f64 c) {
   if (a < b && a < c)
     return a;
@@ -233,26 +238,6 @@ static f64 max3_(f64 a, f64 b, f64 c) {
   return c;
 }
 
-static f64 min4_(f64 a, f64 b, f64 c, f64 d) {
-  if (a < b && a < c && a < d)
-    return a;
-  if (b < c && b < d)
-    return b;
-  if (c < d)
-    return c;
-  return d;
-}
-
-static f64 max4_(f64 a, f64 b, f64 c, f64 d) {
-  if (a > b && a > c && a > d)
-    return a;
-  if (b > c && b > d)
-    return b;
-  if (c > d)
-    return c;
-  return d;
-}
-
 static b8 same_sign_(f64 a, f64 b) {
   if (a >=  EPSILON && b <= -EPSILON) return 0;
   if (a <= -EPSILON && b >=  EPSILON) return 0;
@@ -274,15 +259,19 @@ static f64 gamma_re_(f64 x) {
 static void put_pixel_alpha_(Pixel_Buffer dst, vec4_f32 color, i64 x, i64 y) {
   i64 n = y * dst.stride + x;
 
-  vec4_f32 dst_color = dst.pixels[n];
-  f64      a         = color.w;
-
-  dst.pixels[n] = (vec4_f32) {
-    .x = (f32) (dst_color.x * (1. - a) + color.x * a),
-    .y = (f32) (dst_color.y * (1. - a) + color.y * a),
-    .z = (f32) (dst_color.z * (1. - a) + color.z * a),
-    .w = 1.,
-  };
+  if (color.w == 1.f)
+    dst.pixels[n] = color;
+  else {
+    vec4_f32 dst_color  = dst.pixels[n];
+    f32      dst_amount = 1. - color.w;
+
+    dst.pixels[n] = (vec4_f32) {
+      .x = dst_color.x * dst_amount + color.x * color.w,
+      .y = dst_color.y * dst_amount + color.y * color.w,
+      .z = dst_color.z * dst_amount + color.z * color.w,
+      .w = max2_f32_(dst_color.w, color.w),
+    };
+  }
 }
 
 void draw_pixels_raw(Pixel_Buffer dst, f64 x0, f64 y0, f64 w, f64 h, Pixel_Buffer src) {
@@ -442,6 +431,8 @@ void fill_triangle_raw(Pixel_Buffer dst, vec4_f32 color, f64 x0, f64 y0, f64 x1,
   if (j1 >= dst.height) j1 = dst.height - 1;
 
   for (i64 j = j0; j <= j1; ++j) {
+    //  FIXME, PERF: Calculate the exact intersection.
+
     i64 left  = i1;
     i64 right = i0;
 
@@ -474,6 +465,8 @@ void fill_quad_raw(Pixel_Buffer dst, vec4_f32 color, f64 x0, f64 y0, f64 x1, f64
   if (j1 >= dst.height) j1 = dst.height - 1;
 
   for (i64 j = j0; j <= j1; ++j) {
+    //  FIXME, PERF: Calculate the exact intersection.
+
     i64 left  = i1;
     i64 right = i0;
 
@@ -495,33 +488,33 @@ void fill_quad_raw(Pixel_Buffer dst, vec4_f32 color, f64 x0, f64 y0, f64 x1, f64
 }
 
 void fill_ellipse_raw(Pixel_Buffer dst, vec4_f32 color, f64 x0, f64 y0, f64 w, f64 h) {
-  f64 x1 = x0 + w;
   f64 y1 = y0 + h;
 
-  i64 i0 = (i64) floor(x0);
-  i64 i1 = (i64) ceil (x1);
   i64 j0 = (i64) floor(y0);
   i64 j1 = (i64) ceil (y1);
 
   if (j0 < 0)           j0 = 0;
   if (j1 >= dst.height) j1 = dst.height - 1;
 
+  f64 half_w = w / 2.0;
+  f64 half_h = h / 2.0;
+
+  if (half_h < EPSILON)
+    return;
+  f64 inv_half_h = 1.0 / half_h;
+
+  f64 cx = x0 + half_w;
+  f64 cy = y0 + half_h;
+
   for (i64 j = j0; j <= j1; ++j) {
-    i64 left  = i1;
-    i64 right = i0;
+    f64 ry = (j - cy) * inv_half_h;
+    if (ry > 1.0 - EPSILON || ry < -1.0 + EPSILON)
+      continue;
 
-    for (i64 i = i0; i <= i1; ++i)
-      if (ellipse_contains(x0, y0, x1 - x0, y1 - y0, (f64) i, (f64) j)) {
-        left  = i;
-        right = (i64) ceil(x0 + x1 - left); // symmetry
-        break;
-      }
+    f64 dx = half_w * sqrt(1.0 - ry * ry);
 
-    for (i64 i = right; i >= i0; --i)
-      if (ellipse_contains(x0, y0, x1 - x0, y1 - y0, (f64) i, (f64) j)) {
-        right = i;
-        break;
-      }
+    i64 left  = (i64) ceil (cx - dx - EPSILON);
+    i64 right = (i64) floor(cx + dx + EPSILON);
 
     if (left  <  0)         left  = 0;
     if (right >= dst.width) right = dst.width - 1;
@@ -1164,9 +1157,7 @@ b8 line_contains(f64 x0, f64 y0, f64 x1, f64 y1, f64 width, f64 px, f64 py) {
   tx *= width * .5;
   ty *= width * .5;
 
-  return
-       triangle_contains(x0 - tx, y0 - ty, x0 + tx, y0 + ty, x1 + tx, y1 + ty, px, py)
-    || triangle_contains(x0 - tx, y0 - ty, x1 + tx, y1 + ty, x1 - tx, y1 - ty, px, py);
+  return quad_contains(x0 - tx, y0 - ty, x0 + tx, y0 + ty, x1 + tx, y1 + ty, x1 - tx, y1 - ty, px, py);
 }
 
 //  ================================================================
@@ -1326,8 +1317,8 @@ Gx_Request gx_scaled_(Gx_Request req, vec2 scale) {
       scaled.quad.vertices[1].y *= scale.y;
       scaled.quad.vertices[2].x *= scale.x;
       scaled.quad.vertices[2].y *= scale.y;
-      scaled.quad.vertices[4].x *= scale.x;
-      scaled.quad.vertices[4].y *= scale.y;
+      scaled.quad.vertices[3].x *= scale.x;
+      scaled.quad.vertices[3].y *= scale.y;
       break;
 
     case OP_ELLIPSE:
-- 
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