[core] Use cpp files for shader source

src/mbgl/shaders/fill_pattern.cpp

@@ -0,0 +1,145 @@
+// NOTE: DO NOT CHANGE THIS FILE. IT IS AUTOMATICALLY GENERATED.
+
+#include <mbgl/shaders/fill_pattern.hpp>
+
+namespace mbgl {
+namespace shaders {
+
+const char* fill_pattern::name = "fill_pattern";
+const char* fill_pattern::vertexSource = R"MBGL_SHADER(
+#ifdef GL_ES
+precision highp float;
+#else
+
+#if !defined(lowp)
+#define lowp
+#endif
+
+#if !defined(mediump)
+#define mediump
+#endif
+
+#if !defined(highp)
+#define highp
+#endif
+
+#endif
+
+float evaluate_zoom_function_1(const vec4 values, const float t) {
+    if (t < 1.0) {
+        return mix(values[0], values[1], t);
+    } else if (t < 2.0) {
+        return mix(values[1], values[2], t - 1.0);
+    } else {
+        return mix(values[2], values[3], t - 2.0);
+    }
+}
+vec4 evaluate_zoom_function_4(const vec4 value0, const vec4 value1, const vec4 value2, const vec4 value3, const float t) {
+    if (t < 1.0) {
+        return mix(value0, value1, t);
+    } else if (t < 2.0) {
+        return mix(value1, value2, t - 1.0);
+    } else {
+        return mix(value2, value3, t - 2.0);
+    }
+}
+
+// The offset depends on how many pixels are between the world origin and the edge of the tile:
+// vec2 offset = mod(pixel_coord, size)
+//
+// At high zoom levels there are a ton of pixels between the world origin and the edge of the tile.
+// The glsl spec only guarantees 16 bits of precision for highp floats. We need more than that.
+//
+// The pixel_coord is passed in as two 16 bit values:
+// pixel_coord_upper = floor(pixel_coord / 2^16)
+// pixel_coord_lower = mod(pixel_coord, 2^16)
+//
+// The offset is calculated in a series of steps that should preserve this precision:
+vec2 get_pattern_pos(const vec2 pixel_coord_upper, const vec2 pixel_coord_lower,
+    const vec2 pattern_size, const float tile_units_to_pixels, const vec2 pos) {
+
+    vec2 offset = mod(mod(mod(pixel_coord_upper, pattern_size) * 256.0, pattern_size) * 256.0 + pixel_coord_lower, pattern_size);
+    return (tile_units_to_pixels * pos + offset) / pattern_size;
+}
+uniform mat4 u_matrix;
+uniform vec2 u_pattern_size_a;
+uniform vec2 u_pattern_size_b;
+uniform vec2 u_pixel_coord_upper;
+uniform vec2 u_pixel_coord_lower;
+uniform float u_scale_a;
+uniform float u_scale_b;
+uniform float u_tile_units_to_pixels;
+
+attribute vec2 a_pos;
+
+varying vec2 v_pos_a;
+varying vec2 v_pos_b;
+
+uniform lowp float a_opacity_t;
+attribute lowp float a_opacity_min;
+attribute lowp float a_opacity_max;
+varying lowp float opacity;
+
+void main() {
+    opacity = mix(a_opacity_min, a_opacity_max, a_opacity_t);
+
+    gl_Position = u_matrix * vec4(a_pos, 0, 1);
+
+    v_pos_a = get_pattern_pos(u_pixel_coord_upper, u_pixel_coord_lower, u_scale_a * u_pattern_size_a, u_tile_units_to_pixels, a_pos);
+    v_pos_b = get_pattern_pos(u_pixel_coord_upper, u_pixel_coord_lower, u_scale_b * u_pattern_size_b, u_tile_units_to_pixels, a_pos);
+}
+
+)MBGL_SHADER";
+const char* fill_pattern::fragmentSource = R"MBGL_SHADER(
+#ifdef GL_ES
+precision mediump float;
+#else
+
+#if !defined(lowp)
+#define lowp
+#endif
+
+#if !defined(mediump)
+#define mediump
+#endif
+
+#if !defined(highp)
+#define highp
+#endif
+
+#endif
+uniform vec2 u_pattern_tl_a;
+uniform vec2 u_pattern_br_a;
+uniform vec2 u_pattern_tl_b;
+uniform vec2 u_pattern_br_b;
+uniform float u_mix;
+
+uniform sampler2D u_image;
+
+varying vec2 v_pos_a;
+varying vec2 v_pos_b;
+
+varying lowp float opacity;
+
+void main() {
+    
+
+    vec2 imagecoord = mod(v_pos_a, 1.0);
+    vec2 pos = mix(u_pattern_tl_a, u_pattern_br_a, imagecoord);
+    vec4 color1 = texture2D(u_image, pos);
+
+    vec2 imagecoord_b = mod(v_pos_b, 1.0);
+    vec2 pos2 = mix(u_pattern_tl_b, u_pattern_br_b, imagecoord_b);
+    vec4 color2 = texture2D(u_image, pos2);
+
+    gl_FragColor = mix(color1, color2, u_mix) * opacity;
+
+#ifdef OVERDRAW_INSPECTOR
+    gl_FragColor = vec4(1.0);
+#endif
+}
+
+)MBGL_SHADER";
+
+} // namespace shaders
+} // namespace mbgl