90 lines
1.3 KiB
Go
90 lines
1.3 KiB
Go
package canvas
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import (
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"fmt"
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)
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var gli GL
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//go:generate go run make_shaders.go
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//go:generate go fmt
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func glError() error {
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glErr := gli.GetError()
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if glErr != gl_NO_ERROR {
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return fmt.Errorf("GL Error: %x", glErr)
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}
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return nil
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}
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var (
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buf uint32
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sr *solidShader
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tr *textureShader
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)
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func LoadGL(glimpl GL) (err error) {
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gli = glimpl
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gli.GetError() // clear error state
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sr, err = loadSolidShader()
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if err != nil {
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return
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}
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err = glError()
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if err != nil {
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return
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}
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tr, err = loadTextureShader()
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if err != nil {
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return
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}
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err = glError()
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if err != nil {
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return
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}
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gli.GenBuffers(1, &buf)
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err = glError()
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if err != nil {
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return
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}
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gli.Enable(gl_BLEND)
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gli.BlendFunc(gl_SRC_ALPHA, gl_ONE_MINUS_SRC_ALPHA)
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return
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}
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var solidVS = `
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attribute vec2 vertex;
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void main() {
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gl_Position = vec4(vertex, 0.0, 1.0);
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}`
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var solidFS = `
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#ifdef GL_ES
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precision mediump float;
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#endif
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uniform vec4 color;
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void main() {
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gl_FragColor = color;
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}`
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var textureVS = `
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attribute vec2 vertex, texCoord;
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varying vec2 v_texCoord;
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void main() {
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v_texCoord = texCoord;
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gl_Position = vec4(vertex, 0.0, 1.0);
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}`
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var textureFS = `
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#ifdef GL_ES
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precision mediump float;
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#endif
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varying vec2 v_texCoord;
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uniform sampler2D image;
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void main() {
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gl_FragColor = texture2D(image, v_texCoord);
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}`
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