Add graphics tests; Fix triangles rendering

1 files changed, 233 insertions, 5 deletions

diff --git a/graphics.c b/graphics.c
index a962ba6..5e9790e 100644
--- a/graphics.c
+++ b/graphics.c
@@ -413,11 +413,23 @@ void fill_triangles_to_buffer(Pixel_Buffer dst, vec4_f32 color, vec2 position, v
 
   for (i64 j = j0; j <= j1; ++j)
     for (i64 i = i0; i <= i1; ++i)
-      for (i64 k = 0; k < num_triangles; ++k)
-        if (hit_triangle(vertices + 3 * k, (vec2) { (f64) i, (f64) j, })) {
+      for (i64 k = 0; k < num_triangles; ++k) {
+        vec2 triangle[3] = {
+          vertices[3 * k],
+          vertices[3 * k + 1],
+          vertices[3 * k + 2],
+        };
+
+        for (i64 r = 0; r < 3; ++r) {
+          triangle[r].x = position.x + triangle[r].x * scale. x;
+          triangle[r].y = position.y + triangle[r].y * scale.y;
+        }
+
+        if (hit_triangle(triangle, (vec2) { (f64) i, (f64) j, })) {
           put_pixel_(dst.pixels + j * dst.stride + i, color);
           break;
         }
+      }
 
   PROFILER_end(PROFILE_FILL_TRIANGLES);
 }
@@ -493,14 +505,14 @@ void fill_ellipse_to_buffer(Pixel_Buffer dst, vec4_f32 color, Box area) {
   f64 cy = area.y + half_h;
 
   for (i64 j = j0; j <= j1; ++j) {
-    f64 ry = (j - cy) * inv_half_h;
+    f64 ry = (j - cy + 0.5) * inv_half_h;
     if (ry > 1.0 - EPSILON || ry < -1.0 + EPSILON)
       continue;
 
     f64 dx = half_w * sqrt(1.0 - ry * ry);
 
-    i64 left  = (i64) ceil (cx - dx - EPSILON);
-    i64 right = (i64) floor(cx + dx + EPSILON);
+    i64 left  = (i64) floor(cx - dx + 0.5);
+    i64 right = (i64) floor(cx + dx - 0.5);
 
     if (left  <  0)         left  = 0;
     if (right >= dst.width) right = dst.width - 1;
@@ -2359,6 +2371,222 @@ TEST("rectangle aliasing") {
   REQUIRE(ok);
 }
 
+TEST("triangle") {
+  i64 w = 10;
+  i64 h = 10;
+
+  vec4_f32 pixels[100] = {0};
+
+  fill_triangle_to_buffer(
+    (Pixel_Buffer) { .width = w, .height = h, .stride = w, .pixels = pixels, },
+    (vec4_f32)     { 1.0f, 1.0f, 1.0f, 1.0f },
+    (vec2[3]) {
+      { 1.0, 1.0 },
+      { 5.9, 1.0 },
+      { 1.0, 5.9 },
+    }
+  );
+
+  b8 expect_bits[100] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 1, 1, 1, 1, 1, 0, 0, 0, 0,
+    0, 1, 1, 1, 1, 0, 0, 0, 0, 0,
+    0, 1, 1, 1, 0, 0, 0, 0, 0, 0,
+    0, 1, 1, 0, 0, 0, 0, 0, 0, 0,
+    0, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  };
+
+  b8 ok = 1;
+
+  for (i64 i = 0; i < w * h; ++i) {
+    if (expect_bits[i] != (pixels[i].x > 0.5) ||
+        expect_bits[i] != (pixels[i].y > 0.5) ||
+        expect_bits[i] != (pixels[i].z > 0.5) ||
+        expect_bits[i] != (pixels[i].w > 0.5)) {
+      ok = 0;
+      break;
+    }
+  }
+
+  REQUIRE(ok);
+}
+
+TEST("triangles") {
+  i64 w = 10;
+  i64 h = 10;
+
+  vec4_f32 pixels[100] = {0};
+
+  fill_triangles_to_buffer(
+    (Pixel_Buffer) { .width = w, .height = h, .stride = w, .pixels = pixels, },
+    (vec4_f32)     { 1.0f, 1.0f, 1.0f, 1.0f },
+    (vec2)         { 1.0, 1.0 },
+    (vec2)         { 1.0, 1.0 },
+    2,
+    (vec2[6]) {
+      { 0.0, 0.0 }, { 3.1, 0.0 }, { 0.0, 3.1 },
+      { 4.1, 0.9 }, { 0.9, 4.1 }, { 4.1, 4.1 },
+    }
+  );
+
+  b8 expect_bits[100] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 1, 1, 1, 1, 0, 0, 0, 0, 0,
+    0, 1, 1, 1, 0, 1, 0, 0, 0, 0,
+    0, 1, 1, 0, 1, 1, 0, 0, 0, 0,
+    0, 1, 0, 1, 1, 1, 0, 0, 0, 0,
+    0, 0, 1, 1, 1, 1, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  };
+
+  b8 ok = 1;
+
+  for (i64 i = 0; i < w * h; ++i) {
+    if (expect_bits[i] != (pixels[i].x > 0.5) ||
+        expect_bits[i] != (pixels[i].y > 0.5) ||
+        expect_bits[i] != (pixels[i].z > 0.5) ||
+        expect_bits[i] != (pixels[i].w > 0.5)) {
+      ok = 0;
+      break;
+    }
+  }
+
+  REQUIRE(ok);
+}
+
+TEST("quad") {
+  i64 w = 10;
+  i64 h = 10;
+
+  vec4_f32 pixels[100] = {0};
+
+  fill_quad_to_buffer(
+    (Pixel_Buffer) { .width = w, .height = h, .stride = w, .pixels = pixels, },
+    (vec4_f32)     { 1.0f, 1.0f, 1.0f, 1.0f },
+    (vec2[4]) {
+      { 4.0, 0.9 },
+      { 7.1, 4.0 },
+      { 4.0, 7.1 },
+      { 0.9, 4.0 },
+    }
+  );
+
+  b8 expect_bits[100] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 1, 0, 0, 0, 0, 0,
+    0, 0, 0, 1, 1, 1, 0, 0, 0, 0,
+    0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
+    0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
+    0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
+    0, 0, 0, 1, 1, 1, 0, 0, 0, 0,
+    0, 0, 0, 0, 1, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  };
+
+  b8 ok = 1;
+
+  for (i64 i = 0; i < w * h; ++i) {
+    if (expect_bits[i] != (pixels[i].x > 0.5) ||
+        expect_bits[i] != (pixels[i].y > 0.5) ||
+        expect_bits[i] != (pixels[i].z > 0.5) ||
+        expect_bits[i] != (pixels[i].w > 0.5)) {
+      ok = 0;
+      break;
+    }
+  }
+
+  REQUIRE(ok);
+}
+
+TEST("ellipse") {
+  i64 w = 10;
+  i64 h = 10;
+
+  vec4_f32 pixels[100] = {0};
+
+  fill_ellipse_to_buffer(
+    (Pixel_Buffer) { .width = w, .height = h, .stride = w, .pixels = pixels, },
+    (vec4_f32)     { 1.0f, 1.0f, 1.0f, 1.0f },
+    (Box)          { 0.9, 0.9, 9.2, 9.2 }
+  );
+
+  b8 expect_bits[100] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 1, 1, 1, 1, 1, 0, 0,
+    0, 0, 1, 1, 1, 1, 1, 1, 1, 0,
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    0, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+    0, 0, 1, 1, 1, 1, 1, 1, 1, 0,
+    0, 0, 0, 1, 1, 1, 1, 1, 0, 0,
+  };
+
+  b8 ok = 1;
+
+  for (i64 i = 0; i < w * h; ++i) {
+    if (expect_bits[i] != (pixels[i].x > 0.5) ||
+        expect_bits[i] != (pixels[i].y > 0.5) ||
+        expect_bits[i] != (pixels[i].z > 0.5) ||
+        expect_bits[i] != (pixels[i].w > 0.5)) {
+      ok = 0;
+      break;
+    }
+  }
+
+  REQUIRE(ok);
+}
+
+TEST("line") {
+  i64 w = 10;
+  i64 h = 10;
+
+  vec4_f32 pixels[100] = {0};
+
+  fill_line_to_buffer(
+    (Pixel_Buffer) { .width = w, .height = h, .stride = w, .pixels = pixels, },
+    (vec4_f32)     { 1.0f, 1.0f, 1.0f, 1.0f },
+    (vec2[2])      { { 1.0, 1.0 }, { 8.0, 3.0 }, },
+    1.0
+  );
+
+  b8 expect_bits[100] = {
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 1, 1, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 1, 1, 1, 1, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+  };
+
+  b8 ok = 1;
+
+  for (i64 i = 0; i < w * h; ++i) {
+    if (expect_bits[i] != (pixels[i].x > 0.5) ||
+        expect_bits[i] != (pixels[i].y > 0.5) ||
+        expect_bits[i] != (pixels[i].z > 0.5) ||
+        expect_bits[i] != (pixels[i].w > 0.5)) {
+      ok = 0;
+      break;
+    }
+  }
+
+  REQUIRE(ok);
+}
+
 TEST("text letter A") {
   i64 w = 10;
   i64 h = 10;