1 files changed, 62 insertions, 0 deletions
diff --git a/gfx/wr/webrender/res/cs_scale.glsl b/gfx/wr/webrender/res/cs_scale.glsl
new file mode 100644
index 0000000000..0b4f5d744b
--- /dev/null
+++ b/gfx/wr/webrender/res/cs_scale.glsl
@@ -0,0 +1,62 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// This shader must remain compatible with ESSL 1, at least for the
+// WR_FEATURE_TEXTURE_EXTERNAL_ESSL1 feature, so that it can be used to render
+// video on GLES devices without GL_OES_EGL_image_external_essl3 support.
+// This means we cannot use textureSize(), int inputs/outputs, etc.
+
+#include shared
+
+varying highp vec2 vUv;
+flat varying highp vec4 vUvRect;
+#ifdef WR_FEATURE_TEXTURE_EXTERNAL_ESSL1
+uniform vec2 uTextureSize;
+#endif
+
+#ifdef WR_VERTEX_SHADER
+
+PER_INSTANCE attribute vec4 aScaleTargetRect;
+PER_INSTANCE attribute vec4 aScaleSourceRect;
+
+void main(void) {
+    vec2 src_offset = aScaleSourceRect.xy;
+    vec2 src_size = aScaleSourceRect.zw - aScaleSourceRect.xy;
+
+    // If this is in WR_FEATURE_TEXTURE_RECT mode, the rect and size use
+    // non-normalized texture coordinates.
+#ifdef WR_FEATURE_TEXTURE_RECT
+    vec2 texture_size = vec2(1, 1);
+#elif defined(WR_FEATURE_TEXTURE_EXTERNAL_ESSL1)
+    vec2 texture_size = uTextureSize;
+#else
+    vec2 texture_size = vec2(TEX_SIZE(sColor0));
+#endif
+
+    // The uvs may be inverted, so use the min and max for the bounds
+    vUvRect = vec4(min(aScaleSourceRect.xy, aScaleSourceRect.zw) + vec2(0.5),
+                   max(aScaleSourceRect.xy, aScaleSourceRect.zw) - vec2(0.5)) / texture_size.xyxy;
+
+    vec2 pos = mix(aScaleTargetRect.xy, aScaleTargetRect.zw, aPosition.xy);
+    vUv = (src_offset + src_size * aPosition.xy) / texture_size;
+
+    gl_Position = uTransform * vec4(pos, 0.0, 1.0);
+}
+
+#endif
+
+#ifdef WR_FRAGMENT_SHADER
+
+void main(void) {
+    vec2 st = clamp(vUv, vUvRect.xy, vUvRect.zw);
+    oFragColor = TEX_SAMPLE(sColor0, st);
+}
+
+#ifdef SWGL_DRAW_SPAN
+void swgl_drawSpanRGBA8() {
+    swgl_commitTextureLinearRGBA8(sColor0, vUv, vUvRect);
+}
+#endif
+
+#endif