| // Copyright 2013 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef TRANSFORM_GLSL_ |
| #define TRANSFORM_GLSL_ |
| |
| /// Returns the Cartesian coordinates of `position` in `transform` space. |
| vec2 IPVec2TransformPosition(mat4 matrix, vec2 point) { |
| vec4 transformed = matrix * vec4(point, 0, 1); |
| return transformed.xy / transformed.w; |
| } |
| |
| // Returns the transformed gl_Position for a given glyph position in a glyph |
| // atlas. |
| vec4 IPPositionForGlyphPosition(mat4 mvp, |
| vec2 unit_position, |
| vec2 destination_position, |
| vec2 destination_size) { |
| mat4 translation = mat4(1, 0, 0, 0, // |
| 0, 1, 0, 0, // |
| 0, 0, 1, 0, // |
| destination_position.xy, 0, 1); |
| return mvp * translation * |
| vec4(unit_position.x * destination_size.x, |
| unit_position.y * destination_size.y, 0.0, 1.0); |
| } |
| |
| #endif |
