1 files changed, 284 insertions, 0 deletions
diff --git a/gfx/wr/webrender/res/prim_shared.glsl b/gfx/wr/webrender/res/prim_shared.glsl
new file mode 100644
index 0000000000..4afd147f4e
--- /dev/null
+++ b/gfx/wr/webrender/res/prim_shared.glsl
@@ -0,0 +1,284 @@
+/* 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/. */
+
+#include rect,render_task,gpu_cache,transform
+
+#define EXTEND_MODE_CLAMP  0
+#define EXTEND_MODE_REPEAT 1
+
+#define SUBPX_DIR_NONE        0
+#define SUBPX_DIR_HORIZONTAL  1
+#define SUBPX_DIR_VERTICAL    2
+#define SUBPX_DIR_MIXED       3
+
+#define RASTER_LOCAL            0
+#define RASTER_SCREEN           1
+
+uniform sampler2D sClipMask;
+
+vec2 clamp_rect(vec2 pt, RectWithSize rect) {
+    return clamp(pt, rect.p0, rect.p0 + rect.size);
+}
+
+#ifndef SWGL
+// TODO: convert back to RectWithEndPoint if driver issues are resolved, if ever.
+flat varying vec4 vClipMaskUvBounds;
+// XY and W are homogeneous coordinates, Z is the layer index
+varying vec4 vClipMaskUv;
+#endif
+
+#ifdef WR_VERTEX_SHADER
+
+#define COLOR_MODE_FROM_PASS          0
+#define COLOR_MODE_ALPHA              1
+#define COLOR_MODE_SUBPX_CONST_COLOR  2
+#define COLOR_MODE_SUBPX_BG_PASS0     3
+#define COLOR_MODE_SUBPX_BG_PASS1     4
+#define COLOR_MODE_SUBPX_BG_PASS2     5
+#define COLOR_MODE_SUBPX_DUAL_SOURCE  6
+#define COLOR_MODE_BITMAP             7
+#define COLOR_MODE_COLOR_BITMAP       8
+#define COLOR_MODE_IMAGE              9
+
+uniform HIGHP_SAMPLER_FLOAT sampler2D sPrimitiveHeadersF;
+uniform HIGHP_SAMPLER_FLOAT isampler2D sPrimitiveHeadersI;
+
+// Instanced attributes
+PER_INSTANCE in ivec4 aData;
+
+#define VECS_PER_PRIM_HEADER_F 2U
+#define VECS_PER_PRIM_HEADER_I 2U
+
+struct Instance
+{
+    int prim_header_address;
+    int picture_task_address;
+    int clip_address;
+    int segment_index;
+    int flags;
+    int resource_address;
+    int brush_kind;
+};
+
+Instance decode_instance_attributes() {
+    Instance instance;
+
+    instance.prim_header_address = aData.x;
+    instance.picture_task_address = aData.y >> 16;
+    instance.clip_address = aData.y & 0xffff;
+    instance.segment_index = aData.z & 0xffff;
+    instance.flags = aData.z >> 16;
+    instance.resource_address = aData.w & 0xffffff;
+    instance.brush_kind = aData.w >> 24;
+
+    return instance;
+}
+
+struct PrimitiveHeader {
+    RectWithSize local_rect;
+    RectWithSize local_clip_rect;
+    float z;
+    int specific_prim_address;
+    int transform_id;
+    ivec4 user_data;
+};
+
+PrimitiveHeader fetch_prim_header(int index) {
+    PrimitiveHeader ph;
+
+    ivec2 uv_f = get_fetch_uv(index, VECS_PER_PRIM_HEADER_F);
+    vec4 local_rect = TEXEL_FETCH(sPrimitiveHeadersF, uv_f, 0, ivec2(0, 0));
+    vec4 local_clip_rect = TEXEL_FETCH(sPrimitiveHeadersF, uv_f, 0, ivec2(1, 0));
+    ph.local_rect = RectWithSize(local_rect.xy, local_rect.zw);
+    ph.local_clip_rect = RectWithSize(local_clip_rect.xy, local_clip_rect.zw);
+
+    ivec2 uv_i = get_fetch_uv(index, VECS_PER_PRIM_HEADER_I);
+    ivec4 data0 = TEXEL_FETCH(sPrimitiveHeadersI, uv_i, 0, ivec2(0, 0));
+    ivec4 data1 = TEXEL_FETCH(sPrimitiveHeadersI, uv_i, 0, ivec2(1, 0));
+    ph.z = float(data0.x);
+    ph.specific_prim_address = data0.y;
+    ph.transform_id = data0.z;
+    ph.user_data = data1;
+
+    return ph;
+}
+
+struct VertexInfo {
+    vec2 local_pos;
+    vec4 world_pos;
+};
+
+VertexInfo write_vertex(vec2 local_pos,
+                        RectWithSize local_clip_rect,
+                        float z,
+                        Transform transform,
+                        PictureTask task) {
+    // Clamp to the two local clip rects.
+    vec2 clamped_local_pos = clamp_rect(local_pos, local_clip_rect);
+
+    // Transform the current vertex to world space.
+    vec4 world_pos = transform.m * vec4(clamped_local_pos, 0.0, 1.0);
+
+    // Convert the world positions to device pixel space.
+    vec2 device_pos = world_pos.xy * task.device_pixel_scale;
+
+    // Apply offsets for the render task to get correct screen location.
+    vec2 final_offset = -task.content_origin + task.common_data.task_rect.p0;
+
+    gl_Position = uTransform * vec4(device_pos + final_offset * world_pos.w, z * world_pos.w, world_pos.w);
+
+    VertexInfo vi = VertexInfo(
+        clamped_local_pos,
+        world_pos
+    );
+
+    return vi;
+}
+
+float cross2(vec2 v0, vec2 v1) {
+    return v0.x * v1.y - v0.y * v1.x;
+}
+
+// Return intersection of line (p0,p1) and line (p2,p3)
+vec2 intersect_lines(vec2 p0, vec2 p1, vec2 p2, vec2 p3) {
+    vec2 d0 = p0 - p1;
+    vec2 d1 = p2 - p3;
+
+    float s0 = cross2(p0, p1);
+    float s1 = cross2(p2, p3);
+
+    float d = cross2(d0, d1);
+    float nx = s0 * d1.x - d0.x * s1;
+    float ny = s0 * d1.y - d0.y * s1;
+
+    return vec2(nx / d, ny / d);
+}
+
+VertexInfo write_transform_vertex(RectWithSize local_segment_rect,
+                                  RectWithSize local_prim_rect,
+                                  RectWithSize local_clip_rect,
+                                  vec4 clip_edge_mask,
+                                  float z,
+                                  Transform transform,
+                                  PictureTask task) {
+    // Calculate a clip rect from local_rect + local clip
+    RectWithEndpoint clip_rect = to_rect_with_endpoint(local_clip_rect);
+    RectWithEndpoint segment_rect = to_rect_with_endpoint(local_segment_rect);
+    segment_rect.p0 = clamp(segment_rect.p0, clip_rect.p0, clip_rect.p1);
+    segment_rect.p1 = clamp(segment_rect.p1, clip_rect.p0, clip_rect.p1);
+
+    // Calculate a clip rect from local_rect + local clip
+    RectWithEndpoint prim_rect = to_rect_with_endpoint(local_prim_rect);
+    prim_rect.p0 = clamp(prim_rect.p0, clip_rect.p0, clip_rect.p1);
+    prim_rect.p1 = clamp(prim_rect.p1, clip_rect.p0, clip_rect.p1);
+
+    // As this is a transform shader, extrude by 2 (local space) pixels
+    // in each direction. This gives enough space around the edge to
+    // apply distance anti-aliasing. Technically, it:
+    // (a) slightly over-estimates the number of required pixels in the simple case.
+    // (b) might not provide enough edge in edge case perspective projections.
+    // However, it's fast and simple. If / when we ever run into issues, we
+    // can do some math on the projection matrix to work out a variable
+    // amount to extrude.
+
+    // Only extrude along edges where we are going to apply AA.
+    float extrude_amount = 2.0;
+    vec4 extrude_distance = vec4(extrude_amount) * clip_edge_mask;
+    local_segment_rect.p0 -= extrude_distance.xy;
+    local_segment_rect.size += extrude_distance.xy + extrude_distance.zw;
+
+    // Select the corner of the local rect that we are processing.
+    vec2 local_pos = local_segment_rect.p0 + local_segment_rect.size * aPosition.xy;
+
+    // Convert the world positions to device pixel space.
+    vec2 task_offset = task.common_data.task_rect.p0 - task.content_origin;
+
+    // Transform the current vertex to the world cpace.
+    vec4 world_pos = transform.m * vec4(local_pos, 0.0, 1.0);
+    vec4 final_pos = vec4(
+        world_pos.xy * task.device_pixel_scale + task_offset * world_pos.w,
+        z * world_pos.w,
+        world_pos.w
+    );
+
+    gl_Position = uTransform * final_pos;
+
+    init_transform_vs(mix(
+        vec4(prim_rect.p0, prim_rect.p1),
+        vec4(segment_rect.p0, segment_rect.p1),
+        clip_edge_mask
+    ));
+
+    VertexInfo vi = VertexInfo(
+        local_pos,
+        world_pos
+    );
+
+    return vi;
+}
+
+void write_clip(vec4 world_pos, ClipArea area, PictureTask task) {
+#ifdef SWGL
+    swgl_clipMask(
+        sClipMask,
+        (task.common_data.task_rect.p0 - task.content_origin) - (area.common_data.task_rect.p0 - area.screen_origin),
+        area.common_data.task_rect.p0,
+        area.common_data.task_rect.size
+    );
+#else
+    vec2 uv = world_pos.xy * area.device_pixel_scale +
+        world_pos.w * (area.common_data.task_rect.p0 - area.screen_origin);
+    vClipMaskUvBounds = vec4(
+        area.common_data.task_rect.p0,
+        area.common_data.task_rect.p0 + area.common_data.task_rect.size
+    );
+    vClipMaskUv = vec4(uv, area.common_data.texture_layer_index, world_pos.w);
+#endif
+}
+
+// Read the exta image data containing the homogeneous screen space coordinates
+// of the corners, interpolate between them, and return real screen space UV.
+vec2 get_image_quad_uv(int address, vec2 f) {
+    ImageResourceExtra extra_data = fetch_image_resource_extra(address);
+    vec4 x = mix(extra_data.st_tl, extra_data.st_tr, f.x);
+    vec4 y = mix(extra_data.st_bl, extra_data.st_br, f.x);
+    vec4 z = mix(x, y, f.y);
+    return z.xy / z.w;
+}
+#endif //WR_VERTEX_SHADER
+
+#ifdef WR_FRAGMENT_SHADER
+
+struct Fragment {
+    vec4 color;
+#ifdef WR_FEATURE_DUAL_SOURCE_BLENDING
+    vec4 blend;
+#endif
+};
+
+float do_clip() {
+#ifdef SWGL
+    // SWGL relies on builtin clip-mask support to do this more efficiently,
+    // so no clipping is required here.
+    return 1.0;
+#else
+    // check for the dummy bounds, which are given to the opaque objects
+    if (vClipMaskUvBounds.xy == vClipMaskUvBounds.zw) {
+        return 1.0;
+    }
+    // anything outside of the mask is considered transparent
+    //Note: we assume gl_FragCoord.w == interpolated(1 / vClipMaskUv.w)
+    vec2 mask_uv = vClipMaskUv.xy * gl_FragCoord.w;
+    bvec2 left = lessThanEqual(vClipMaskUvBounds.xy, mask_uv); // inclusive
+    bvec2 right = greaterThan(vClipMaskUvBounds.zw, mask_uv); // non-inclusive
+    // bail out if the pixel is outside the valid bounds
+    if (!all(bvec4(left, right))) {
+        return 0.0;
+    }
+    // finally, the slow path - fetch the mask value from an image
+    return texelFetch(sClipMask, ivec2(mask_uv), 0).r;
+#endif
+}
+
+#endif //WR_FRAGMENT_SHADER