github.com/utopiagio/gio@v0.0.8/app/gl_ios.go (about)

     1  // SPDX-License-Identifier: Unlicense OR MIT
     2  
     3  //go:build darwin && ios && nometal
     4  // +build darwin,ios,nometal
     5  
     6  package app
     7  
     8  /*
     9  @import UIKit;
    10  
    11  #include <CoreFoundation/CoreFoundation.h>
    12  #include <OpenGLES/ES2/gl.h>
    13  #include <OpenGLES/ES2/glext.h>
    14  
    15  __attribute__ ((visibility ("hidden"))) int gio_renderbufferStorage(CFTypeRef ctx, CFTypeRef layer, GLenum buffer);
    16  __attribute__ ((visibility ("hidden"))) int gio_presentRenderbuffer(CFTypeRef ctx, GLenum buffer);
    17  __attribute__ ((visibility ("hidden"))) int gio_makeCurrent(CFTypeRef ctx);
    18  __attribute__ ((visibility ("hidden"))) CFTypeRef gio_createContext(void);
    19  __attribute__ ((visibility ("hidden"))) CFTypeRef gio_createGLLayer(void);
    20  
    21  static CFTypeRef getViewLayer(CFTypeRef viewRef) {
    22  	@autoreleasepool {
    23  		UIView *view = (__bridge UIView *)viewRef;
    24  		return CFBridgingRetain(view.layer);
    25  	}
    26  }
    27  
    28  */
    29  import "C"
    30  
    31  import (
    32  	"errors"
    33  	"fmt"
    34  	"runtime"
    35  
    36  	"github.com/utopiagio/gio/gpu"
    37  	"github.com/utopiagio/gio/internal/gl"
    38  )
    39  
    40  type context struct {
    41  	owner       *window
    42  	c           *gl.Functions
    43  	ctx         C.CFTypeRef
    44  	layer       C.CFTypeRef
    45  	init        bool
    46  	frameBuffer gl.Framebuffer
    47  	colorBuffer gl.Renderbuffer
    48  }
    49  
    50  func newContext(w *window) (*context, error) {
    51  	ctx := C.gio_createContext()
    52  	if ctx == 0 {
    53  		return nil, fmt.Errorf("failed to create EAGLContext")
    54  	}
    55  	api := contextAPI()
    56  	f, err := gl.NewFunctions(api.Context, api.ES)
    57  	if err != nil {
    58  		return nil, err
    59  	}
    60  	c := &context{
    61  		ctx:   ctx,
    62  		owner: w,
    63  		layer: C.getViewLayer(w.contextView()),
    64  		c:     f,
    65  	}
    66  	return c, nil
    67  }
    68  
    69  func contextAPI() gpu.OpenGL {
    70  	return gpu.OpenGL{}
    71  }
    72  
    73  func (c *context) RenderTarget() gpu.RenderTarget {
    74  	return gpu.OpenGLRenderTarget(c.frameBuffer)
    75  }
    76  
    77  func (c *context) API() gpu.API {
    78  	return contextAPI()
    79  }
    80  
    81  func (c *context) Release() {
    82  	if c.ctx == 0 {
    83  		return
    84  	}
    85  	C.gio_renderbufferStorage(c.ctx, 0, C.GLenum(gl.RENDERBUFFER))
    86  	c.c.DeleteFramebuffer(c.frameBuffer)
    87  	c.c.DeleteRenderbuffer(c.colorBuffer)
    88  	C.gio_makeCurrent(0)
    89  	C.CFRelease(c.ctx)
    90  	c.ctx = 0
    91  }
    92  
    93  func (c *context) Present() error {
    94  	if c.layer == 0 {
    95  		panic("context is not active")
    96  	}
    97  	c.c.BindRenderbuffer(gl.RENDERBUFFER, c.colorBuffer)
    98  	if C.gio_presentRenderbuffer(c.ctx, C.GLenum(gl.RENDERBUFFER)) == 0 {
    99  		return errors.New("presentRenderBuffer failed")
   100  	}
   101  	return nil
   102  }
   103  
   104  func (c *context) Lock() error {
   105  	// OpenGL contexts are implicit and thread-local. Lock the OS thread.
   106  	runtime.LockOSThread()
   107  
   108  	if C.gio_makeCurrent(c.ctx) == 0 {
   109  		return errors.New("[EAGLContext setCurrentContext] failed")
   110  	}
   111  	return nil
   112  }
   113  
   114  func (c *context) Unlock() {
   115  	C.gio_makeCurrent(0)
   116  }
   117  
   118  func (c *context) Refresh() error {
   119  	if C.gio_makeCurrent(c.ctx) == 0 {
   120  		return errors.New("[EAGLContext setCurrentContext] failed")
   121  	}
   122  	if !c.init {
   123  		c.init = true
   124  		c.frameBuffer = c.c.CreateFramebuffer()
   125  		c.colorBuffer = c.c.CreateRenderbuffer()
   126  	}
   127  	if !c.owner.visible {
   128  		// Make sure any in-flight GL commands are complete.
   129  		c.c.Finish()
   130  		return nil
   131  	}
   132  	currentRB := gl.Renderbuffer{uint(c.c.GetInteger(gl.RENDERBUFFER_BINDING))}
   133  	c.c.BindRenderbuffer(gl.RENDERBUFFER, c.colorBuffer)
   134  	if C.gio_renderbufferStorage(c.ctx, c.layer, C.GLenum(gl.RENDERBUFFER)) == 0 {
   135  		return errors.New("renderbufferStorage failed")
   136  	}
   137  	c.c.BindRenderbuffer(gl.RENDERBUFFER, currentRB)
   138  	c.c.BindFramebuffer(gl.FRAMEBUFFER, c.frameBuffer)
   139  	c.c.FramebufferRenderbuffer(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.RENDERBUFFER, c.colorBuffer)
   140  	if st := c.c.CheckFramebufferStatus(gl.FRAMEBUFFER); st != gl.FRAMEBUFFER_COMPLETE {
   141  		return fmt.Errorf("framebuffer incomplete, status: %#x\n", st)
   142  	}
   143  	return nil
   144  }
   145  
   146  func (w *window) NewContext() (Context, error) {
   147  	return newContext(w)
   148  }