ebiten/internal/graphicsdriver/opengl/graphics.go

325 lines
8.4 KiB
Go

// Copyright 2018 The Ebiten Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package opengl
import (
"fmt"
"runtime"
"unsafe"
"github.com/hajimehoshi/ebiten/v2/internal/graphics"
"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/opengl/gl"
"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
)
type activatedTexture struct {
textureNative textureNative
index int
}
type Graphics struct {
state openGLState
context context
nextImageID graphicsdriver.ImageID
images map[graphicsdriver.ImageID]*Image
nextShaderID graphicsdriver.ShaderID
shaders map[graphicsdriver.ShaderID]*Shader
// drawCalled is true just after Draw is called. This holds true until WritePixels is called.
drawCalled bool
uniformVariableNameCache map[int]string
textureVariableNameCache map[int]string
uniformVars []uniformVariable
// activatedTextures is a set of activated textures.
// textureNative cannot be a map key unfortunately.
activatedTextures []activatedTexture
}
func newGraphics(ctx gl.Context) *Graphics {
g := &Graphics{}
if isDebug {
g.context.ctx = &gl.DebugContext{Context: ctx}
} else {
g.context.ctx = ctx
}
return g
}
func (g *Graphics) Begin() error {
// Do nothing.
return nil
}
func (g *Graphics) End(present bool) error {
// Call glFlush to prevent black flicking (especially on Android (#226) and iOS).
// TODO: examples/sprites worked without this. Is this really needed?
g.context.ctx.Flush()
// The last uniforms must be reset after swapping the buffer (#2517).
if present {
g.state.resetLastUniforms()
}
return nil
}
func (g *Graphics) SetTransparent(transparent bool) {
// Do nothing.
}
func (g *Graphics) checkSize(width, height int) {
if width < 1 {
panic(fmt.Sprintf("opengl: width (%d) must be equal or more than %d", width, 1))
}
if height < 1 {
panic(fmt.Sprintf("opengl: height (%d) must be equal or more than %d", height, 1))
}
m := g.context.getMaxTextureSize()
if width > m {
panic(fmt.Sprintf("opengl: width (%d) must be less than or equal to %d", width, m))
}
if height > m {
panic(fmt.Sprintf("opengl: height (%d) must be less than or equal to %d", height, m))
}
}
func (g *Graphics) genNextImageID() graphicsdriver.ImageID {
g.nextImageID++
return g.nextImageID
}
func (g *Graphics) genNextShaderID() graphicsdriver.ShaderID {
g.nextShaderID++
return g.nextShaderID
}
func (g *Graphics) NewImage(width, height int) (graphicsdriver.Image, error) {
i := &Image{
id: g.genNextImageID(),
graphics: g,
width: width,
height: height,
}
w := graphics.InternalImageSize(width)
h := graphics.InternalImageSize(height)
g.checkSize(w, h)
t, err := g.context.newTexture(w, h)
if err != nil {
return nil, err
}
i.texture = t
g.addImage(i)
return i, nil
}
func (g *Graphics) NewScreenFramebufferImage(width, height int) (graphicsdriver.Image, error) {
g.checkSize(width, height)
i := &Image{
id: g.genNextImageID(),
graphics: g,
width: width,
height: height,
screen: true,
}
g.addImage(i)
return i, nil
}
func (g *Graphics) addImage(img *Image) {
if g.images == nil {
g.images = map[graphicsdriver.ImageID]*Image{}
}
if _, ok := g.images[img.id]; ok {
panic(fmt.Sprintf("opengl: image ID %d was already registered", img.id))
}
g.images[img.id] = img
}
func (g *Graphics) removeImage(img *Image) {
delete(g.images, img.id)
}
func (g *Graphics) Initialize() error {
return g.state.reset(&g.context)
}
// Reset resets or initializes the current OpenGL state.
func (g *Graphics) Reset() error {
return g.state.reset(&g.context)
}
func (g *Graphics) SetVertices(vertices []float32, indices []uint32) error {
g.state.setVertices(&g.context, vertices, indices)
return nil
}
func (g *Graphics) uniformVariableName(idx int) string {
if v, ok := g.uniformVariableNameCache[idx]; ok {
return v
}
if g.uniformVariableNameCache == nil {
g.uniformVariableNameCache = map[int]string{}
}
name := fmt.Sprintf("U%d", idx)
g.uniformVariableNameCache[idx] = name
return name
}
func (g *Graphics) DrawTriangles(dstID graphicsdriver.ImageID, srcIDs [graphics.ShaderImageCount]graphicsdriver.ImageID, shaderID graphicsdriver.ShaderID, dstRegions []graphicsdriver.DstRegion, indexOffset int, blend graphicsdriver.Blend, uniforms []uint32, evenOdd bool) error {
if shaderID == graphicsdriver.InvalidShaderID {
return fmt.Errorf("opengl: shader ID is invalid")
}
destination := g.images[dstID]
g.drawCalled = true
if err := destination.setViewport(); err != nil {
return err
}
g.context.blend(blend)
shader := g.shaders[shaderID]
program := shader.p
ulen := len(shader.ir.Uniforms)
if cap(g.uniformVars) < ulen {
g.uniformVars = make([]uniformVariable, ulen)
} else {
g.uniformVars = g.uniformVars[:ulen]
}
var idx int
for i, typ := range shader.ir.Uniforms {
n := typ.Uint32Count()
g.uniformVars[i].name = g.uniformVariableName(i)
g.uniformVars[i].value = uniforms[idx : idx+n]
g.uniformVars[i].typ = typ
idx += n
}
// In OpenGL, the NDC's Y direction is upward, so flip the Y direction for the final framebuffer.
if destination.screen {
const idx = graphics.ProjectionMatrixUniformVariableIndex
// Invert the sign bits as float32 values.
g.uniformVars[idx].value[1] ^= 1 << 31
g.uniformVars[idx].value[5] ^= 1 << 31
g.uniformVars[idx].value[9] ^= 1 << 31
g.uniformVars[idx].value[13] ^= 1 << 31
}
var imgs [graphics.ShaderImageCount]textureVariable
for i, srcID := range srcIDs {
if srcID == graphicsdriver.InvalidImageID {
continue
}
imgs[i].valid = true
imgs[i].native = g.images[srcID].texture
}
if err := g.useProgram(program, g.uniformVars, imgs); err != nil {
return err
}
for i := range g.uniformVars {
g.uniformVars[i] = uniformVariable{}
}
g.uniformVars = g.uniformVars[:0]
if evenOdd {
if err := destination.ensureStencilBuffer(); err != nil {
return err
}
g.context.ctx.Enable(gl.STENCIL_TEST)
}
for _, dstRegion := range dstRegions {
g.context.ctx.Scissor(
int32(dstRegion.Region.Min.X),
int32(dstRegion.Region.Min.Y),
int32(dstRegion.Region.Dx()),
int32(dstRegion.Region.Dy()),
)
if evenOdd {
g.context.ctx.Clear(gl.STENCIL_BUFFER_BIT)
g.context.ctx.StencilFunc(gl.ALWAYS, 0x00, 0xff)
g.context.ctx.StencilOp(gl.KEEP, gl.KEEP, gl.INVERT)
g.context.ctx.ColorMask(false, false, false, false)
g.context.ctx.DrawElements(gl.TRIANGLES, int32(dstRegion.IndexCount), gl.UNSIGNED_INT, indexOffset*int(unsafe.Sizeof(uint32(0))))
g.context.ctx.StencilFunc(gl.NOTEQUAL, 0x00, 0xff)
g.context.ctx.StencilOp(gl.KEEP, gl.KEEP, gl.KEEP)
g.context.ctx.ColorMask(true, true, true, true)
}
g.context.ctx.DrawElements(gl.TRIANGLES, int32(dstRegion.IndexCount), gl.UNSIGNED_INT, indexOffset*int(unsafe.Sizeof(uint32(0))))
indexOffset += dstRegion.IndexCount
}
if evenOdd {
g.context.ctx.Disable(gl.STENCIL_TEST)
}
return nil
}
func (g *Graphics) SetVsyncEnabled(enabled bool) {
// Do nothing
}
func (g *Graphics) NeedsRestoring() bool {
// Though it is possible to have a logic to restore the graphics data for GPU, do not use it for performance (#1603).
if runtime.GOOS == "js" {
return false
}
return g.context.ctx.IsES()
}
func (g *Graphics) NeedsClearingScreen() bool {
return true
}
func (g *Graphics) MaxImageSize() int {
return g.context.getMaxTextureSize()
}
func (g *Graphics) NewShader(program *shaderir.Program) (graphicsdriver.Shader, error) {
s, err := newShader(g.genNextShaderID(), g, program)
if err != nil {
return nil, err
}
g.addShader(s)
return s, nil
}
func (g *Graphics) addShader(shader *Shader) {
if g.shaders == nil {
g.shaders = map[graphicsdriver.ShaderID]*Shader{}
}
if _, ok := g.shaders[shader.id]; ok {
panic(fmt.Sprintf("opengl: shader ID %d was already registered", shader.id))
}
g.shaders[shader.id] = shader
}
func (g *Graphics) removeShader(shader *Shader) {
delete(g.shaders, shader.id)
}