补充注释

This commit is contained in:
caizhitao 2020-01-09 10:47:18 +08:00
parent 7380cf3292
commit 6ba48af6aa
2 changed files with 42 additions and 8 deletions

View File

@ -96,13 +96,47 @@ CCProgram fs %{
ALPHA_TEST(o);
#if ENABLE_ROUNDCORNER
// 约束圆角半径范围在 [0.0, 0.5]
float radius = clamp(0.0, 0.5, roundCornerRadius);
// 将纹理uv往左下偏移实现偏移后的纹理中心点在 OpenGL 坐标系的原点
vec2 uv = v_uv0.xy - vec2(0.5, 0.5);
float rx = abs(uv.x) - (0.5 - roundCornerRadius);
float ry = abs(uv.y) - (0.5 - roundCornerRadius);
float mx = step(0.5 - roundCornerRadius, abs(uv.x));
float my = step(0.5 - roundCornerRadius, abs(uv.y));
float radius = length(vec2(rx, ry));
float a = 1.0 - mx * my * step(roundCornerRadius, radius) * smoothstep(0., roundCornerRadius * 0.01, radius - roundCornerRadius);
// uv.x , uv.y : 为偏移后的的uv
// abs(uv.x) , abs(uv.y) : 将第二、三、四象限的点都投影到第一象限上,这样子只需要处理第一象限的情况就可以,简化判断
// 0.5 - radius : 计算出第一象限的圆角所在圆的圆心坐标
// (rx, ry) : 偏移映射后的 新的uv 坐标,相对于 第一象限圆角坐在圆心坐标 的相对坐标
float rx = abs(uv.x) - (0.5 - radius);
float ry = abs(uv.y) - (0.5 - radius);
// 区分 以第一象限圆角所在圆心坐标为原点的坐标的四个象限
//
// 第一象限 mx = 1, my = 1
// 第二象限 mx = 0, my = 1
// 第三象限 mx = 0, my = 0
// 第四象限 mx = 1, my = 0
//
// 当 mx * my 时只要等于1那就是标识第一象限实际对应圆角区域所在矩形否则就是第二、三、四象限
float mx = step(0.5 - radius, abs(uv.x));
float my = step(0.5 - radius, abs(uv.y));
// 计算相对uv坐标到圆心的距离
float len = length(vec2(rx, ry));
// mx * my = 0 时代表非圆角区域a 值为1代表完全采用原始纹理的透明度
// mx * my = 1 时,代表园所所在矩形区域
// step(radius, len) 可以区分出圆角所在矩形区域的 圆角区域 和 非圆角区域
// 其中圆角区域值为0非圆角区域值为1
// 当为圆角区域时a 值为1代表完全采用原始纹理透明度
// 当为非圆角区域时a 值为0代表完全透明
// 至此已经实现圆角裁剪
//
// smoothstep(0., radius * 0.01, len - radius) 是用于抗锯齿优化
// 原理:针对点在非圆角区域的情况,针对点在大于「圆半径一点点」地方的区域,进行平滑过渡,以实现抗锯齿
// 其中,
// 「圆半径一点点」用 radius * 0.01 表示0.01 可自行改变)
// 点在大于圆半径的区域用 len - radius ,此值会在 [0.0, radius * 0.01] 之间时会平滑过渡
float a = 1.0 - mx * my * step(radius, len) * smoothstep(0., radius * 0.01, len - radius);
o = vec4(o.rgb, o.a * a);
#endif
gl_FragColor = o;

View File

@ -5,11 +5,11 @@
{
"glsl1": {
"vert": "\nprecision highp float;\nuniform mat4 cc_matViewProj;\nuniform mat4 cc_matWorld;\n\nattribute vec3 a_position;\nattribute vec4 a_color;\nvarying vec4 v_color;\n\n#if USE_TEXTURE\nattribute vec2 a_uv0;\nvarying vec2 v_uv0;\n#endif\n\nvoid main () {\n vec4 pos = vec4(a_position, 1);\n\n #if CC_USE_MODEL\n pos = cc_matViewProj * cc_matWorld * pos;\n #else\n pos = cc_matViewProj * pos;\n #endif\n\n #if USE_TEXTURE\n v_uv0 = a_uv0;\n #endif\n\n v_color = a_color;\n\n gl_Position = pos;\n}\n",
"frag": "\nprecision highp float;\n\n#if USE_ALPHA_TEST\n \n uniform float alphaThreshold;\n#endif\n\nvoid ALPHA_TEST (in vec4 color) {\n #if USE_ALPHA_TEST\n if (color.a < alphaThreshold) discard;\n #endif\n}\n\nvoid ALPHA_TEST (in float alpha) {\n #if USE_ALPHA_TEST\n if (alpha < alphaThreshold) discard;\n #endif\n}\n\nvarying vec4 v_color;\n\n#if USE_TEXTURE\nvarying vec2 v_uv0;\nuniform sampler2D texture;\n#endif\n\n#if ENABLE_ROUNDCORNER\nuniform float roundCornerRadius;\n#endif\n\nvoid main () {\n vec4 o = vec4(1, 1, 1, 1);\n\n #if USE_TEXTURE\n o *= texture2D(texture, v_uv0);\n #if CC_USE_ALPHA_ATLAS_TEXTURE\n o.a *= texture2D(texture, v_uv0 + vec2(0, 0.5)).r;\n #endif\n #endif\n\n o *= v_color;\n\n ALPHA_TEST(o);\n\n #if ENABLE_ROUNDCORNER\n vec2 uv = v_uv0.xy - vec2(0.5, 0.5);\n float rx = abs(uv.x) - (0.5 - roundCornerRadius);\n float ry = abs(uv.y) - (0.5 - roundCornerRadius);\n float mx = step(0.5 - roundCornerRadius, abs(uv.x));\n float my = step(0.5 - roundCornerRadius, abs(uv.y));\n float radius = length(vec2(rx, ry));\n float a = 1.0 - mx * my * step(roundCornerRadius, radius) * smoothstep(0., roundCornerRadius * 0.01, radius - roundCornerRadius);\n o = vec4(o.rgb, o.a * a);\n #endif\n gl_FragColor = o;\n}\n"
"frag": "\nprecision highp float;\n\n#if USE_ALPHA_TEST\n \n uniform float alphaThreshold;\n#endif\n\nvoid ALPHA_TEST (in vec4 color) {\n #if USE_ALPHA_TEST\n if (color.a < alphaThreshold) discard;\n #endif\n}\n\nvoid ALPHA_TEST (in float alpha) {\n #if USE_ALPHA_TEST\n if (alpha < alphaThreshold) discard;\n #endif\n}\n\nvarying vec4 v_color;\n\n#if USE_TEXTURE\nvarying vec2 v_uv0;\nuniform sampler2D texture;\n#endif\n\n#if ENABLE_ROUNDCORNER\nuniform float roundCornerRadius;\n#endif\n\nvoid main () {\n vec4 o = vec4(1, 1, 1, 1);\n\n #if USE_TEXTURE\n o *= texture2D(texture, v_uv0);\n #if CC_USE_ALPHA_ATLAS_TEXTURE\n o.a *= texture2D(texture, v_uv0 + vec2(0, 0.5)).r;\n #endif\n #endif\n\n o *= v_color;\n\n ALPHA_TEST(o);\n\n #if ENABLE_ROUNDCORNER\n\n float radius = clamp(0.0, 0.5, roundCornerRadius);\n\n vec2 uv = v_uv0.xy - vec2(0.5, 0.5);\n\n float rx = abs(uv.x) - (0.5 - radius);\n float ry = abs(uv.y) - (0.5 - radius);\n\n float mx = step(0.5 - radius, abs(uv.x));\n float my = step(0.5 - radius, abs(uv.y));\n\n float len = length(vec2(rx, ry));\n\n float a = 1.0 - mx * my * step(radius, len) * smoothstep(0., radius * 0.01, len - radius);\n o = vec4(o.rgb, o.a * a);\n #endif\n gl_FragColor = o;\n}\n"
},
"glsl3": {
"vert": "\nprecision highp float;\nuniform CCGlobal {\n vec4 cc_time;\n\n vec4 cc_screenSize;\n\n vec4 cc_screenScale;\n\n vec4 cc_nativeSize;\n\n mat4 cc_matView;\n mat4 cc_matViewInv;\n mat4 cc_matProj;\n mat4 cc_matProjInv;\n mat4 cc_matViewProj;\n mat4 cc_matViewProjInv;\n vec4 cc_cameraPos;\n\n vec4 cc_exposure;\n\n vec4 cc_mainLitDir;\n\n vec4 cc_mainLitColor;\n\n vec4 cc_ambientSky;\n vec4 cc_ambientGround;\n};\nuniform CCLocal {\n mat4 cc_matWorld;\n mat4 cc_matWorldIT;\n};\n\nin vec3 a_position;\nin vec4 a_color;\nout vec4 v_color;\n\n#if USE_TEXTURE\nin vec2 a_uv0;\nout vec2 v_uv0;\n#endif\n\nvoid main () {\n vec4 pos = vec4(a_position, 1);\n\n #if CC_USE_MODEL\n pos = cc_matViewProj * cc_matWorld * pos;\n #else\n pos = cc_matViewProj * pos;\n #endif\n\n #if USE_TEXTURE\n v_uv0 = a_uv0;\n #endif\n\n v_color = a_color;\n\n gl_Position = pos;\n}\n",
"frag": "\nprecision highp float;\n\n#if USE_ALPHA_TEST\n \n uniform ALPHA_TEST {\n float alphaThreshold;\n }\n#endif\n\nvoid ALPHA_TEST (in vec4 color) {\n #if USE_ALPHA_TEST\n if (color.a < alphaThreshold) discard;\n #endif\n}\n\nvoid ALPHA_TEST (in float alpha) {\n #if USE_ALPHA_TEST\n if (alpha < alphaThreshold) discard;\n #endif\n}\n\nin vec4 v_color;\n\n#if USE_TEXTURE\nin vec2 v_uv0;\nuniform sampler2D texture;\n#endif\n\n#if ENABLE_ROUNDCORNER\nuniform RoundCorner {\n\n float roundCornerRadius;\n}\n#endif\n\nvoid main () {\n vec4 o = vec4(1, 1, 1, 1);\n\n #if USE_TEXTURE\n o *= texture(texture, v_uv0);\n #if CC_USE_ALPHA_ATLAS_TEXTURE\n o.a *= texture2D(texture, v_uv0 + vec2(0, 0.5)).r;\n #endif\n #endif\n\n o *= v_color;\n\n ALPHA_TEST(o);\n\n #if ENABLE_ROUNDCORNER\n vec2 uv = v_uv0.xy - vec2(0.5, 0.5);\n float rx = abs(uv.x) - (0.5 - roundCornerRadius);\n float ry = abs(uv.y) - (0.5 - roundCornerRadius);\n float mx = step(0.5 - roundCornerRadius, abs(uv.x));\n float my = step(0.5 - roundCornerRadius, abs(uv.y));\n float radius = length(vec2(rx, ry));\n float a = 1.0 - mx * my * step(roundCornerRadius, radius) * smoothstep(0., roundCornerRadius * 0.01, radius - roundCornerRadius);\n o = vec4(o.rgb, o.a * a);\n #endif\n gl_FragColor = o;\n}\n"
"frag": "\nprecision highp float;\n\n#if USE_ALPHA_TEST\n \n uniform ALPHA_TEST {\n float alphaThreshold;\n }\n#endif\n\nvoid ALPHA_TEST (in vec4 color) {\n #if USE_ALPHA_TEST\n if (color.a < alphaThreshold) discard;\n #endif\n}\n\nvoid ALPHA_TEST (in float alpha) {\n #if USE_ALPHA_TEST\n if (alpha < alphaThreshold) discard;\n #endif\n}\n\nin vec4 v_color;\n\n#if USE_TEXTURE\nin vec2 v_uv0;\nuniform sampler2D texture;\n#endif\n\n#if ENABLE_ROUNDCORNER\nuniform RoundCorner {\n\n float roundCornerRadius;\n}\n#endif\n\nvoid main () {\n vec4 o = vec4(1, 1, 1, 1);\n\n #if USE_TEXTURE\n o *= texture(texture, v_uv0);\n #if CC_USE_ALPHA_ATLAS_TEXTURE\n o.a *= texture2D(texture, v_uv0 + vec2(0, 0.5)).r;\n #endif\n #endif\n\n o *= v_color;\n\n ALPHA_TEST(o);\n\n #if ENABLE_ROUNDCORNER\n\n float radius = clamp(0.0, 0.5, roundCornerRadius);\n\n vec2 uv = v_uv0.xy - vec2(0.5, 0.5);\n\n float rx = abs(uv.x) - (0.5 - radius);\n float ry = abs(uv.y) - (0.5 - radius);\n\n float mx = step(0.5 - radius, abs(uv.x));\n float my = step(0.5 - radius, abs(uv.y));\n\n float len = length(vec2(rx, ry));\n\n float a = 1.0 - mx * my * step(radius, len) * smoothstep(0., radius * 0.01, len - radius);\n o = vec4(o.rgb, o.a * a);\n #endif\n gl_FragColor = o;\n}\n"
}
}
],