95 lines
2.8 KiB
Go
95 lines
2.8 KiB
Go
package canvas
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import (
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"image"
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"unsafe"
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)
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func (cv *Canvas) drawShadow(tris []float32) {
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if len(tris) == 0 || cv.state.shadowColor.a == 0 {
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return
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}
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ox, oy := float32(cv.state.shadowOffsetX), float32(cv.state.shadowOffsetY)
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count := len(tris)
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for i := 12; i < count; i += 2 {
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tris[i] += ox
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tris[i+1] += oy
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}
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gli.BindBuffer(gl_ARRAY_BUFFER, shadowBuf)
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gli.BufferData(gl_ARRAY_BUFFER, len(tris)*4, unsafe.Pointer(&tris[0]), gl_STREAM_DRAW)
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gli.ColorMask(false, false, false, false)
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gli.StencilFunc(gl_ALWAYS, 1, 0xFF)
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gli.StencilOp(gl_REPLACE, gl_REPLACE, gl_REPLACE)
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gli.StencilMask(0x01)
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gli.UseProgram(sr.id)
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gli.Uniform4f(sr.color, 0, 0, 0, 0)
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gli.Uniform2f(sr.canvasSize, float32(cv.fw), float32(cv.fh))
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gli.EnableVertexAttribArray(sr.vertex)
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gli.VertexAttribPointer(sr.vertex, 2, gl_FLOAT, false, 0, 0)
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gli.DrawArrays(gl_TRIANGLES, 6, int32(len(tris)/2-6))
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gli.DisableVertexAttribArray(sr.vertex)
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gli.ColorMask(true, true, true, true)
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gli.StencilFunc(gl_EQUAL, 1, 0xFF)
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var style drawStyle
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style.color = cv.state.shadowColor
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vertex := cv.useShader(&style)
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gli.EnableVertexAttribArray(vertex)
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gli.VertexAttribPointer(vertex, 2, gl_FLOAT, false, 0, 0)
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gli.DrawArrays(gl_TRIANGLES, 0, 6)
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gli.DisableVertexAttribArray(vertex)
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gli.StencilOp(gl_KEEP, gl_KEEP, gl_KEEP)
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gli.StencilFunc(gl_ALWAYS, 0, 0xFF)
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gli.Clear(gl_STENCIL_BUFFER_BIT)
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gli.StencilMask(0xFF)
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}
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func (cv *Canvas) drawTextShadow(offset image.Point, strWidth, strHeight int, x, y float64) {
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x += cv.state.shadowOffsetX
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y += cv.state.shadowOffsetY
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gli.StencilFunc(gl_EQUAL, 0, 0xFF)
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gli.BindBuffer(gl_ARRAY_BUFFER, buf)
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var style drawStyle
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style.color = cv.state.shadowColor
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vertex, alphaTexCoord := cv.useAlphaShader(&style, 1)
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gli.EnableVertexAttribArray(vertex)
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gli.EnableVertexAttribArray(alphaTexCoord)
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p0 := cv.tf(vec{float64(offset.X) + x, float64(offset.Y) + y})
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p1 := cv.tf(vec{float64(offset.X) + x, float64(offset.Y+strHeight) + y})
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p2 := cv.tf(vec{float64(offset.X+strWidth) + x, float64(offset.Y+strHeight) + y})
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p3 := cv.tf(vec{float64(offset.X+strWidth) + x, float64(offset.Y) + y})
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tw := float64(strWidth) / alphaTexSize
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th := float64(strHeight) / alphaTexSize
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data := [16]float32{float32(p0[0]), float32(p0[1]), float32(p1[0]), float32(p1[1]), float32(p2[0]), float32(p2[1]), float32(p3[0]), float32(p3[1]),
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0, 1, 0, float32(1 - th), float32(tw), float32(1 - th), float32(tw), 1}
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gli.BufferData(gl_ARRAY_BUFFER, len(data)*4, unsafe.Pointer(&data[0]), gl_STREAM_DRAW)
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gli.VertexAttribPointer(vertex, 2, gl_FLOAT, false, 0, 0)
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gli.VertexAttribPointer(alphaTexCoord, 2, gl_FLOAT, false, 0, 8*4)
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gli.DrawArrays(gl_TRIANGLE_FAN, 0, 4)
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gli.DisableVertexAttribArray(vertex)
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gli.DisableVertexAttribArray(alphaTexCoord)
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gli.ActiveTexture(gl_TEXTURE0)
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gli.StencilFunc(gl_ALWAYS, 0, 0xFF)
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}
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