[docs] Include uncompressed shader source in .cpp comments

This is meant to
(1) Make it easier for new developers to find the source
(2) Make it easier to look at shader diffs when the GL JS pin changes

1 files changed, 142 insertions, 0 deletions

diff --git a/src/mbgl/shaders/symbol_icon.cpp b/src/mbgl/shaders/symbol_icon.cpp
index 47b9c9b331..5b34d490bb 100644
--- a/src/mbgl/shaders/symbol_icon.cpp
+++ b/src/mbgl/shaders/symbol_icon.cpp
@@ -10,5 +10,147 @@ const char* symbol_icon::name = "symbol_icon";
 const char* symbol_icon::vertexSource = source() + 70714;
 const char* symbol_icon::fragmentSource = source() + 74120;
 
+// Uncompressed source of symbol_icon.vertex.glsl:
+/*
+const float PI = 3.141592653589793;
+
+attribute vec4 a_pos_offset;
+attribute vec4 a_data;
+attribute vec3 a_projected_pos;
+attribute float a_fade_opacity;
+
+uniform bool u_is_size_zoom_constant;
+uniform bool u_is_size_feature_constant;
+uniform highp float u_size_t; // used to interpolate between zoom stops when size is a composite function
+uniform highp float u_size; // used when size is both zoom and feature constant
+uniform highp float u_camera_to_center_distance;
+uniform highp float u_pitch;
+uniform bool u_rotate_symbol;
+uniform highp float u_aspect_ratio;
+uniform float u_fade_change;
+
+
+#ifndef HAS_UNIFORM_u_opacity
+uniform lowp float a_opacity_t;
+attribute lowp vec2 a_opacity;
+varying lowp float opacity;
+#else
+uniform lowp float u_opacity;
+#endif
+
+
+uniform mat4 u_matrix;
+uniform mat4 u_label_plane_matrix;
+uniform mat4 u_gl_coord_matrix;
+
+uniform bool u_is_text;
+uniform bool u_pitch_with_map;
+
+uniform vec2 u_texsize;
+
+varying vec2 v_tex;
+varying float v_fade_opacity;
+
+void main() {
+    
+#ifndef HAS_UNIFORM_u_opacity
+    opacity = unpack_mix_vec2(a_opacity, a_opacity_t);
+#else
+    lowp float opacity = u_opacity;
+#endif
+
+
+    vec2 a_pos = a_pos_offset.xy;
+    vec2 a_offset = a_pos_offset.zw;
+
+    vec2 a_tex = a_data.xy;
+    vec2 a_size = a_data.zw;
+
+    highp float segment_angle = -a_projected_pos[2];
+
+    float size;
+    if (!u_is_size_zoom_constant && !u_is_size_feature_constant) {
+        size = mix(a_size[0], a_size[1], u_size_t) / 256.0;
+    } else if (u_is_size_zoom_constant && !u_is_size_feature_constant) {
+        size = a_size[0] / 256.0;
+    } else if (!u_is_size_zoom_constant && u_is_size_feature_constant) {
+        size = u_size;
+    } else {
+        size = u_size;
+    }
+
+    vec4 projectedPoint = u_matrix * vec4(a_pos, 0, 1);
+    highp float camera_to_anchor_distance = projectedPoint.w;
+    // See comments in symbol_sdf.vertex
+    highp float distance_ratio = u_pitch_with_map ?
+        camera_to_anchor_distance / u_camera_to_center_distance :
+        u_camera_to_center_distance / camera_to_anchor_distance;
+    highp float perspective_ratio = clamp(
+            0.5 + 0.5 * distance_ratio,
+            0.0, // Prevents oversized near-field symbols in pitched/overzoomed tiles
+            4.0);
+
+    size *= perspective_ratio;
+
+    float fontScale = u_is_text ? size / 24.0 : size;
+
+    highp float symbol_rotation = 0.0;
+    if (u_rotate_symbol) {
+        // See comments in symbol_sdf.vertex
+        vec4 offsetProjectedPoint = u_matrix * vec4(a_pos + vec2(1, 0), 0, 1);
+
+        vec2 a = projectedPoint.xy / projectedPoint.w;
+        vec2 b = offsetProjectedPoint.xy / offsetProjectedPoint.w;
+
+        symbol_rotation = atan((b.y - a.y) / u_aspect_ratio, b.x - a.x);
+    }
+
+    highp float angle_sin = sin(segment_angle + symbol_rotation);
+    highp float angle_cos = cos(segment_angle + symbol_rotation);
+    mat2 rotation_matrix = mat2(angle_cos, -1.0 * angle_sin, angle_sin, angle_cos);
+
+    vec4 projected_pos = u_label_plane_matrix * vec4(a_projected_pos.xy, 0.0, 1.0);
+    gl_Position = u_gl_coord_matrix * vec4(projected_pos.xy / projected_pos.w + rotation_matrix * (a_offset / 32.0 * fontScale), 0.0, 1.0);
+
+    v_tex = a_tex / u_texsize;
+    vec2 fade_opacity = unpack_opacity(a_fade_opacity);
+    float fade_change = fade_opacity[1] > 0.5 ? u_fade_change : -u_fade_change;
+    v_fade_opacity = max(0.0, min(1.0, fade_opacity[0] + fade_change));
+}
+
+*/
+
+// Uncompressed source of symbol_icon.fragment.glsl:
+/*
+uniform sampler2D u_texture;
+
+
+#ifndef HAS_UNIFORM_u_opacity
+varying lowp float opacity;
+#else
+uniform lowp float u_opacity;
+#endif
+
+
+varying vec2 v_tex;
+varying float v_fade_opacity;
+
+void main() {
+    
+#ifdef HAS_UNIFORM_u_opacity
+    lowp float opacity = u_opacity;
+#endif
+
+
+    lowp float alpha = opacity * v_fade_opacity;
+    gl_FragColor = texture2D(u_texture, v_tex) * alpha;
+
+#ifdef OVERDRAW_INSPECTOR
+    gl_FragColor = vec4(1.0);
+#endif
+}
+
+*/
+
 } // namespace shaders
 } // namespace mbgl