mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-27 20:28:54 +01:00
373 lines
11 KiB
Go
373 lines
11 KiB
Go
package opengl
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// #cgo LDFLAGS: -framework OpenGL
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//
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// #include <stdlib.h>
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// #include <OpenGL/gl.h>
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import "C"
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import (
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"fmt"
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"github.com/hajimehoshi/go.ebiten/graphics"
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"github.com/hajimehoshi/go.ebiten/graphics/matrix"
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"image"
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"image/color"
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"math"
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"unsafe"
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)
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type GraphicsContext struct {
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screenWidth int
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screenHeight int
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screenScale int
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textures map[graphics.TextureID]*Texture
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currentOffscreenWidth int
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currentOffscreenHeight int
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projectionMatrix [16]float32
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currentShaderProgram C.GLuint
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mainFramebuffer C.GLuint
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framebuffers map[C.GLuint]C.GLuint
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}
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// This method should be called on the UI thread.
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func newGraphicsContext(screenWidth, screenHeight, screenScale int) *GraphicsContext {
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context := &GraphicsContext{
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screenWidth: screenWidth,
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screenHeight: screenHeight,
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screenScale: screenScale,
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textures: map[graphics.TextureID]*Texture{},
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mainFramebuffer: 0,
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framebuffers: map[C.GLuint]C.GLuint{},
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}
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// main framebuffer should be created sooner than any other framebuffers!
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mainFramebuffer := C.GLint(0)
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C.glGetIntegerv(C.GL_FRAMEBUFFER_BINDING, &mainFramebuffer)
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context.mainFramebuffer = C.GLuint(mainFramebuffer)
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initializeShaders()
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return context
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}
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func (context *GraphicsContext) Clear() {
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C.glClearColor(0, 0, 0, 0)
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C.glClear(C.GL_COLOR_BUFFER_BIT)
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}
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func (context *GraphicsContext) Fill(clr color.Color) {
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r, g, b, a := clr.RGBA()
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max := float64(math.MaxUint16)
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C.glClearColor(
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C.GLclampf(float64(r)/max),
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C.GLclampf(float64(g)/max),
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C.GLclampf(float64(b)/max),
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C.GLclampf(float64(a)/max))
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C.glClear(C.GL_COLOR_BUFFER_BIT)
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}
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func (context *GraphicsContext) DrawRect(rect graphics.Rect, clr color.Color) {
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width := float32(context.currentOffscreenWidth)
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height := float32(context.currentOffscreenHeight)
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textureWidth := float32(clp2(uint64(width)))
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textureHeight := float32(clp2(uint64(height)))
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// Normalize the coord between -1.0 and 1.0.
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x1 := float32(rect.X)/textureWidth*2.0 - 1.0
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x2 := float32(rect.X+rect.Width)/textureHeight*2.0 - 1.0
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y1 := float32(rect.Y)/textureHeight*2.0 - 1.0
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y2 := float32(rect.Y+rect.Height)/textureHeight*2.0 - 1.0
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vertex := [...]float32{
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x1, y1,
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x2, y1,
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x1, y2,
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x2, y2,
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}
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origR, origG, origB, origA := clr.RGBA()
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max := float32(math.MaxUint16)
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r := float32(origR) / max
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g := float32(origG) / max
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b := float32(origB) / max
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a := float32(origA) / max
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color := [...]float32{
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r, g, b, a,
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r, g, b, a,
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r, g, b, a,
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r, g, b, a,
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}
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C.glUseProgram(0)
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context.currentShaderProgram = 0
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C.glDisable(C.GL_TEXTURE_2D)
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C.glEnableClientState(C.GL_VERTEX_ARRAY)
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C.glEnableClientState(C.GL_COLOR_ARRAY)
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C.glVertexPointer(2, C.GL_FLOAT, C.GL_FALSE, unsafe.Pointer(&vertex[0]))
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C.glColorPointer(4, C.GL_FLOAT, C.GL_FALSE, unsafe.Pointer(&color[0]))
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C.glDrawArrays(C.GL_TRIANGLE_STRIP, 0, 4)
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C.glDisableClientState(C.GL_COLOR_ARRAY)
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C.glDisableClientState(C.GL_VERTEX_ARRAY)
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C.glEnable(C.GL_TEXTURE_2D)
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if glError := C.glGetError(); glError != C.GL_NO_ERROR {
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panic("OpenGL error")
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}
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}
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func (context *GraphicsContext) DrawTexture(
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textureID graphics.TextureID,
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geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
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texture := context.textures[textureID]
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source := graphics.Rect{0, 0, texture.width, texture.height}
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locations := []graphics.TexturePart{{0, 0, source}}
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context.DrawTextureParts(textureID, locations,
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geometryMatrix, colorMatrix)
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}
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func (context *GraphicsContext) DrawTextureParts(
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textureID graphics.TextureID, locations []graphics.TexturePart,
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geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
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texture := context.textures[textureID]
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context.setShaderProgram(geometryMatrix, colorMatrix)
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C.glBindTexture(C.GL_TEXTURE_2D, texture.id)
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vertexAttrLocation := getAttributeLocation(context.currentShaderProgram, "vertex")
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textureAttrLocation := getAttributeLocation(context.currentShaderProgram, "texture")
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C.glEnableClientState(C.GL_VERTEX_ARRAY)
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C.glEnableClientState(C.GL_TEXTURE_COORD_ARRAY)
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C.glEnableVertexAttribArray(C.GLuint(vertexAttrLocation))
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C.glEnableVertexAttribArray(C.GLuint(textureAttrLocation))
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// TODO: Refactoring
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for _, location := range locations {
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x1 := float32(location.LocationX)
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x2 := float32(location.LocationX + location.Source.Width)
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y1 := float32(location.LocationY)
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y2 := float32(location.LocationY + location.Source.Height)
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vertex := [...]float32{
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x1, y1,
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x2, y1,
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x1, y2,
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x2, y2,
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}
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src := location.Source
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tu1 := float32(src.X) / float32(texture.textureWidth)
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tu2 := float32(src.X+src.Width) / float32(texture.textureWidth)
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tv1 := float32(src.Y) / float32(texture.textureHeight)
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tv2 := float32(src.Y+src.Height) / float32(texture.textureHeight)
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texCoord := [...]float32{
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tu1, tv1,
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tu2, tv1,
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tu1, tv2,
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tu2, tv2,
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}
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C.glVertexAttribPointer(C.GLuint(vertexAttrLocation), 2, C.GL_FLOAT, C.GL_FALSE,
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0, unsafe.Pointer(&vertex[0]))
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C.glVertexAttribPointer(C.GLuint(textureAttrLocation), 2, C.GL_FLOAT, C.GL_FALSE,
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0, unsafe.Pointer(&texCoord[0]))
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C.glDrawArrays(C.GL_TRIANGLE_STRIP, 0, 4)
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}
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C.glDisableVertexAttribArray(C.GLuint(textureAttrLocation))
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C.glDisableVertexAttribArray(C.GLuint(vertexAttrLocation))
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C.glDisableClientState(C.GL_TEXTURE_COORD_ARRAY)
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C.glDisableClientState(C.GL_VERTEX_ARRAY)
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}
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func abs(x int) int {
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if x < 0 {
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return -x
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}
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return x
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}
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func (context *GraphicsContext) SetOffscreen(textureID graphics.TextureID) {
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texture := context.textures[textureID]
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context.currentOffscreenWidth = texture.width
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context.currentOffscreenHeight = texture.height
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framebuffer := context.getFramebuffer(texture.id)
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if framebuffer == context.mainFramebuffer {
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panic("invalid framebuffer")
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}
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context.setOffscreenFramebuffer(framebuffer,
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texture.textureWidth, texture.textureHeight)
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}
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func (context *GraphicsContext) setOffscreenFramebuffer(framebuffer C.GLuint,
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textureWidth, textureHeight int) {
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if framebuffer == context.mainFramebuffer {
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textureWidth = int(clp2(uint64(context.screenWidth * context.screenScale)))
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textureHeight = int(clp2(uint64(context.screenHeight * context.screenScale)))
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}
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C.glFlush()
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C.glBindFramebuffer(C.GL_FRAMEBUFFER, framebuffer)
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if err := C.glCheckFramebufferStatus(C.GL_FRAMEBUFFER); err != C.GL_FRAMEBUFFER_COMPLETE {
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panic(fmt.Sprintf("glBindFramebuffer failed: %d", err))
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}
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C.glEnable(C.GL_BLEND)
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C.glBlendFunc(C.GL_SRC_ALPHA, C.GL_ONE_MINUS_SRC_ALPHA)
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C.glViewport(0, 0, C.GLsizei(abs(textureWidth)), C.GLsizei(abs(textureHeight)))
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var e11, e22, e41, e42 float32
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if framebuffer != context.mainFramebuffer {
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e11 = float32(2) / float32(textureWidth)
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e22 = float32(2) / float32(textureWidth)
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e41 = -1
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e42 = -1
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} else {
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height := float32(context.screenHeight) * float32(context.screenScale)
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e11 = float32(2) / float32(textureWidth)
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e22 = -1 * float32(2) / float32(textureHeight)
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e41 = -1
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e42 = -1 + height/float32(textureHeight)*2
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}
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context.projectionMatrix = [...]float32{
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e11, 0, 0, 0,
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0, e22, 0, 0,
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0, 0, 1, 0,
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e41, e42, 0, 1,
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}
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}
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func (context *GraphicsContext) resetOffscreen() {
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context.setOffscreenFramebuffer(context.mainFramebuffer, 0, 0)
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context.currentOffscreenWidth = context.screenWidth * context.screenScale
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context.currentOffscreenHeight = context.screenHeight * context.screenScale
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}
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// This method should be called on the UI thread.
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func (context *GraphicsContext) flush() {
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C.glFlush()
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}
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// This method should be called on the UI thread.
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func (context *GraphicsContext) setShaderProgram(
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geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
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program := C.GLuint(0)
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if colorMatrix.IsIdentity() {
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program = regularShaderProgram
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} else {
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program = colorMatrixShaderProgram
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}
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// TODO: cache and skip?
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C.glUseProgram(program)
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context.currentShaderProgram = program
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C.glUniformMatrix4fv(getUniformLocation(program, "projection_matrix"),
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1, C.GL_FALSE,
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(*C.GLfloat)(&context.projectionMatrix[0]))
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a := float32(geometryMatrix.Elements[0][0])
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b := float32(geometryMatrix.Elements[0][1])
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c := float32(geometryMatrix.Elements[1][0])
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d := float32(geometryMatrix.Elements[1][1])
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tx := float32(geometryMatrix.Elements[0][2])
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ty := float32(geometryMatrix.Elements[1][2])
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glModelviewMatrix := [...]float32{
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a, c, 0, 0,
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b, d, 0, 0,
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0, 0, 1, 0,
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tx, ty, 0, 1,
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}
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C.glUniformMatrix4fv(getUniformLocation(program, "modelview_matrix"),
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1, C.GL_FALSE,
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(*C.GLfloat)(&glModelviewMatrix[0]))
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C.glUniform1i(getUniformLocation(program, "texture"), 0)
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if program != colorMatrixShaderProgram {
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return
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}
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e := [4][5]float32{}
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for i := 0; i < 4; i++ {
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for j := 0; j < 5; j++ {
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e[i][j] = float32(colorMatrix.Elements[i][j])
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}
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}
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glColorMatrix := [...]float32{
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e[0][0], e[1][0], e[2][0], e[3][0],
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e[0][1], e[1][1], e[2][1], e[3][1],
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e[0][2], e[1][2], e[2][2], e[3][2],
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e[0][3], e[1][3], e[2][3], e[3][3],
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}
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C.glUniformMatrix4fv(getUniformLocation(program, "color_matrix"),
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1, C.GL_FALSE, (*C.GLfloat)(&glColorMatrix[0]))
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glColorMatrixTranslation := [...]float32{
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e[0][4], e[1][4], e[2][4], e[3][4],
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}
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C.glUniform4fv(getUniformLocation(program, "color_matrix_translation"),
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1, (*C.GLfloat)(&glColorMatrixTranslation[0]))
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}
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func (context *GraphicsContext) getFramebuffer(textureID C.GLuint) C.GLuint {
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framebuffer, ok := context.framebuffers[textureID]
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if ok {
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return framebuffer
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}
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newFramebuffer := C.GLuint(0)
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C.glGenFramebuffers(1, &newFramebuffer)
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origFramebuffer := C.GLint(0)
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C.glGetIntegerv(C.GL_FRAMEBUFFER_BINDING, &origFramebuffer)
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C.glBindFramebuffer(C.GL_FRAMEBUFFER, newFramebuffer)
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C.glFramebufferTexture2D(C.GL_FRAMEBUFFER, C.GL_COLOR_ATTACHMENT0,
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C.GL_TEXTURE_2D, textureID, 0)
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C.glBindFramebuffer(C.GL_FRAMEBUFFER, C.GLuint(origFramebuffer))
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if C.glCheckFramebufferStatus(C.GL_FRAMEBUFFER) != C.GL_FRAMEBUFFER_COMPLETE {
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panic("creating framebuffer failed")
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}
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context.framebuffers[textureID] = newFramebuffer
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return newFramebuffer
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}
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func (context *GraphicsContext) deleteFramebuffer(textureID C.GLuint) {
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framebuffer, ok := context.framebuffers[textureID]
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if !ok {
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// TODO: panic?
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return
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}
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C.glDeleteFramebuffers(1, &framebuffer)
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delete(context.framebuffers, textureID)
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}
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func (context *GraphicsContext) NewTexture(width, height int) graphics.Texture {
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texture := newTexture(width, height)
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id := graphics.TextureID(texture.id)
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context.textures[id] = texture
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context.SetOffscreen(id)
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context.Clear()
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context.resetOffscreen()
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return graphics.Texture{
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ID: id,
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Width: texture.width,
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Height: texture.height,
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}
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}
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func (context *GraphicsContext) NewTextureFromImage(img image.Image) (graphics.Texture, error) {
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texture, err := newTextureFromImage(img)
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if err != nil {
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return graphics.Texture{}, err
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}
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id := graphics.TextureID(texture.id)
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context.textures[id] = texture
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return graphics.Texture{
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ID: id,
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Width: texture.width,
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Height: texture.height,
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}, nil
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}
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