graphics: Temporary hack for mobile browers

roundTexel doesn't work well on moible browsers
This commit is contained in:
Hajime Hoshi 2017-12-12 03:27:56 +09:00
parent 723d153800
commit aea2e491c3

View File

@ -14,6 +14,12 @@
package graphics
import (
"strings"
"github.com/hajimehoshi/ebiten/internal/web"
)
type shaderId int
const (
@ -22,11 +28,19 @@ const (
)
func shader(id shaderId) string {
return shaders[id]
s := shaders[id]
defs := []string{}
if web.IsMobileBrowser() {
defs = append(defs, "#define IS_MOBILE_BROWSER")
}
s = strings.Replace(s, "{{Definitions}}", strings.Join(defs, "\n"), -1)
return s
}
var shaders = map[shaderId]string{
shaderVertexModelview: `
{{Definitions}}
uniform mat4 projection_matrix;
attribute vec2 vertex;
attribute vec4 tex_coord;
@ -60,17 +74,28 @@ precision mediump float;
#define highp
#endif
{{Definitions}}
uniform sampler2D texture;
uniform mat4 color_matrix;
uniform vec4 color_matrix_translation;
uniform int filter_type;
uniform vec2 source_size;
uniform int filter_type;
varying vec2 varying_tex_coord;
varying vec2 varying_tex_coord_min;
varying vec2 varying_tex_coord_max;
vec2 roundTexel(vec2 p) {
#if defined(IS_MOBILE_BROWSER)
// This is a temporary hack: on mobile browsers like Android Chrome,
// the code to round a float might cause unexpected behavior.
// This is confirmed with rendering a relatively large (e.g. 4096x512) image
// with specifying a source rectangle near its edges.
// TODO: examples/moire doesn't work anyway.
// TODO: Does this function work on an Android native app?
return p;
#else
vec2 factor = 1.0 / (source_size * 256.0);
if (factor.x > 0.0) {
p.x -= mod(p.x + factor.x * 0.5, factor.x) - factor.x * 0.5;
@ -79,6 +104,7 @@ vec2 roundTexel(vec2 p) {
p.y -= mod(p.y + factor.y * 0.5, factor.y) - factor.y * 0.5;
}
return p;
#endif
}
vec4 getColorAt(vec2 pos) {