mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-09-20 05:12:18 +02:00
322 lines
8.8 KiB
Go
322 lines
8.8 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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"math"
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"unsafe"
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)
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type Context struct {
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screenId graphics.RenderTargetId
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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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renderTargets map[graphics.RenderTargetId]*RenderTarget
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renderTargetToTexture map[graphics.RenderTargetId]graphics.TextureId
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currentOffscreen *RenderTarget
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mainFramebufferTexture *RenderTarget
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projectionMatrix [16]float32
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}
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func newContext(screenWidth, screenHeight, screenScale int) *Context {
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context := &Context{
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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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renderTargets: map[graphics.RenderTargetId]*RenderTarget{},
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renderTargetToTexture: map[graphics.RenderTargetId]graphics.TextureId{},
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}
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return context
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}
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func (context *Context) Init() {
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// The main framebuffer should be created sooner than any other
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// 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.mainFramebufferTexture = newRenderTargetWithFramebuffer(
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context.screenWidth*context.screenScale,
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context.screenHeight*context.screenScale,
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C.GLuint(mainFramebuffer))
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initializeShaders()
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var err error
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context.screenId, err = context.NewRenderTarget(
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context.screenWidth, context.screenHeight)
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if err != nil {
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panic("initializing the offscreen failed: " + err.Error())
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}
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}
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func (context *Context) ToTexture(renderTargetId graphics.RenderTargetId) graphics.TextureId {
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return context.renderTargetToTexture[renderTargetId]
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}
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func (context *Context) Clear() {
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context.Fill(0, 0, 0)
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}
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func (context *Context) Fill(r, g, b uint8) {
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const max = float64(math.MaxUint8)
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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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1)
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C.glClear(C.GL_COLOR_BUFFER_BIT)
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}
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func (context *Context) DrawTexture(
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textureId graphics.TextureId,
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geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
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texture, ok := context.textures[textureId]
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if !ok {
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panic("invalid texture ID")
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}
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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 *Context) DrawTextureParts(
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textureId graphics.TextureId, parts []graphics.TexturePart,
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geometryMatrix matrix.Geometry, colorMatrix matrix.Color) {
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texture, ok := context.textures[textureId]
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if !ok {
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panic("invalid texture ID")
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}
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shaderProgram := context.setShaderProgram(geometryMatrix, colorMatrix)
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C.glBindTexture(C.GL_TEXTURE_2D, texture.Native().(C.GLuint))
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vertexAttrLocation := getAttributeLocation(shaderProgram, "vertex")
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textureAttrLocation := getAttributeLocation(shaderProgram, "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: Optimization
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for _, part := range parts {
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x1 := float32(part.LocationX)
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x2 := float32(part.LocationX + part.Source.Width)
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y1 := float32(part.LocationY)
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y2 := float32(part.LocationY + part.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 := part.Source
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tu1 := float32(texture.U(src.X))
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tu2 := float32(texture.U(src.X + src.Width))
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tv1 := float32(texture.V(src.Y))
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tv2 := float32(texture.V(src.Y + src.Height))
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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,
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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,
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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 (context *Context) ResetOffscreen() {
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context.SetOffscreen(context.screenId)
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}
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func (context *Context) SetOffscreen(renderTargetId graphics.RenderTargetId) {
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renderTarget := context.renderTargets[renderTargetId]
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context.setOffscreen(renderTarget)
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}
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func (context *Context) setOffscreen(renderTarget *RenderTarget) {
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context.currentOffscreen = renderTarget
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C.glFlush()
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C.glBindFramebuffer(C.GL_FRAMEBUFFER, renderTarget.framebuffer)
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err := C.glCheckFramebufferStatus(C.GL_FRAMEBUFFER)
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if 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.glBlendFuncSeparate(C.GL_SRC_ALPHA, C.GL_ONE_MINUS_SRC_ALPHA,
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C.GL_ZERO, C.GL_ONE)
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context.currentOffscreen.SetAsViewport(context)
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}
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func orthoProjectionMatrix(left, right, bottom, top int) [4][4]float64 {
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e11 := float64(2) / float64(right-left)
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e22 := float64(2) / float64(top-bottom)
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e14 := -1 * float64(right+left) / float64(right-left)
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e24 := -1 * float64(top+bottom) / float64(top-bottom)
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return [4][4]float64{
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{e11, 0, 0, e14},
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{0, e22, 0, e24},
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{0, 0, 1, 0},
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{0, 0, 0, 1},
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}
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}
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func (context *Context) SetViewport(x, y, width, height int) {
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C.glViewport(C.GLint(x), C.GLint(y), C.GLsizei(width), C.GLsizei(height))
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matrix := orthoProjectionMatrix(x, width, y, height)
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if context.currentOffscreen == context.mainFramebufferTexture {
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// Flip Y and translate
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matrix[1][1] *= -1
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actualHeight := context.screenHeight * context.screenScale
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matrix[1][3] += float64(actualHeight) / float64(height) * 2
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}
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for j := 0; j < 4; j++ {
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for i := 0; i < 4; i++ {
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context.projectionMatrix[i+j*4] = float32(matrix[i][j])
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}
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}
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// TODO: call 'setShaderProgram' here?
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}
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func (context *Context) setMainFramebufferOffscreen() {
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context.setOffscreen(context.mainFramebufferTexture)
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}
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func (context *Context) flush() {
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C.glFlush()
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}
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func (context *Context) setShaderProgram(
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geometryMatrix matrix.Geometry, colorMatrix matrix.Color) (program C.GLuint) {
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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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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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return
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}
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func (context *Context) NewRenderTarget(width, height int) (
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graphics.RenderTargetId, error) {
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renderTarget, err := newRenderTarget(width, height)
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if err != nil {
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return 0, nil
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}
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renderTargetId := graphics.RenderTargetId(<-newId)
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textureId := graphics.TextureId(<-newId)
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context.renderTargets[renderTargetId] = renderTarget
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context.textures[textureId] = renderTarget.texture
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context.renderTargetToTexture[renderTargetId] = textureId
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context.setOffscreen(renderTarget)
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context.Clear()
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// TODO: Is it OK to revert he main framebuffer?
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context.setMainFramebufferOffscreen()
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return renderTargetId, nil
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}
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func (context *Context) NewTextureFromImage(img image.Image) (
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graphics.TextureId, error) {
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texture, err := newTextureFromImage(img)
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if err != nil {
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return 0, err
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}
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textureId := graphics.TextureId(<-newId)
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context.textures[textureId] = texture
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return textureId, nil
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}
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var newId chan int
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func init() {
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newId = make(chan int)
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go func() {
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for i := 0; ; i++ {
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newId <- i
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}
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}()
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}
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