rhi: gl: Make resolve on par with other backends

Just handling attachments with a render buffer set and only one
attachment is not what other backends do. They support all attachments
and also the cases of multisample (2D) textures and multisample texture
arrays.

By extension this allows multisample 2D texture arrays. (GL 3.2+/GLES
3.1+) This was previously not working probably since the correct texture
target was never used.

Pick-to: 6.6
Change-Id: Ibe929faaf86824a596f9794240d1becc51f68e43
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

2 files changed, 115 insertions, 28 deletions

diff --git a/src/gui/rhi/qrhigles2.cpp b/src/gui/rhi/qrhigles2.cpp
index af5f07d6de..8d60cffb18 100644
--- a/src/gui/rhi/qrhigles2.cpp
+++ b/src/gui/rhi/qrhigles2.cpp
@@ -355,6 +355,10 @@ QT_BEGIN_NAMESPACE
 #define GL_TEXTURE_2D_MULTISAMPLE         0x9100
 #endif
 
+#ifndef GL_TEXTURE_2D_MULTISAMPLE_ARRAY
+#define GL_TEXTURE_2D_MULTISAMPLE_ARRAY   0x9102
+#endif
+
 #ifndef GL_TEXTURE_EXTERNAL_OES
 #define GL_TEXTURE_EXTERNAL_OES           0x8D65
 #endif
@@ -3432,17 +3436,55 @@ void QRhiGles2::executeCommandBuffer(QRhiCommandBuffer *cb)
             f->glGenFramebuffers(2, fbo);
             f->glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo[0]);
             f->glFramebufferRenderbuffer(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
-                                         GL_RENDERBUFFER, cmd.args.blitFromRb.renderbuffer);
+                                         GL_RENDERBUFFER, cmd.args.blitFromRenderbuffer.renderbuffer);
             f->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo[1]);
-            if (cmd.args.blitFromRb.target == GL_TEXTURE_3D || cmd.args.blitFromRb.target == GL_TEXTURE_2D_ARRAY) {
+            if (cmd.args.blitFromRenderbuffer.target == GL_TEXTURE_3D || cmd.args.blitFromRenderbuffer.target == GL_TEXTURE_2D_ARRAY) {
                 f->glFramebufferTextureLayer(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
-                                             cmd.args.blitFromRb.texture, cmd.args.blitFromRb.dstLevel, cmd.args.blitFromRb.dstLayer);
+                                             cmd.args.blitFromRenderbuffer.dstTexture,
+                                             cmd.args.blitFromRenderbuffer.dstLevel,
+                                             cmd.args.blitFromRenderbuffer.dstLayer);
             } else {
-                f->glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, cmd.args.blitFromRb.target,
-                                          cmd.args.blitFromRb.texture, cmd.args.blitFromRb.dstLevel);
+                f->glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, cmd.args.blitFromRenderbuffer.target,
+                                          cmd.args.blitFromRenderbuffer.dstTexture, cmd.args.blitFromRenderbuffer.dstLevel);
             }
-            f->glBlitFramebuffer(0, 0, cmd.args.blitFromRb.w, cmd.args.blitFromRb.h,
-                                 0, 0, cmd.args.blitFromRb.w, cmd.args.blitFromRb.h,
+            f->glBlitFramebuffer(0, 0, cmd.args.blitFromRenderbuffer.w, cmd.args.blitFromRenderbuffer.h,
+                                 0, 0, cmd.args.blitFromRenderbuffer.w, cmd.args.blitFromRenderbuffer.h,
+                                 GL_COLOR_BUFFER_BIT,
+                                 GL_NEAREST); // Qt 5 used Nearest when resolving samples, stick to that
+            f->glBindFramebuffer(GL_FRAMEBUFFER, ctx->defaultFramebufferObject());
+            f->glDeleteFramebuffers(2, fbo);
+        }
+            break;
+        case QGles2CommandBuffer::Command::BlitFromTexture:
+        {
+            // Altering the scissor state, so reset the stored state, although
+            // not strictly required as long as blit is done in endPass() only.
+            cbD->graphicsPassState.reset();
+            f->glDisable(GL_SCISSOR_TEST);
+            GLuint fbo[2];
+            f->glGenFramebuffers(2, fbo);
+            f->glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo[0]);
+            if (cmd.args.blitFromTexture.srcTarget == GL_TEXTURE_2D_MULTISAMPLE_ARRAY) {
+                f->glFramebufferTextureLayer(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                                             cmd.args.blitFromTexture.srcTexture,
+                                             cmd.args.blitFromTexture.srcLevel,
+                                             cmd.args.blitFromTexture.srcLayer);
+            } else {
+                f->glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, cmd.args.blitFromTexture.srcTarget,
+                                          cmd.args.blitFromTexture.srcTexture, cmd.args.blitFromTexture.srcLevel);
+            }
+            f->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo[1]);
+            if (cmd.args.blitFromTexture.dstTarget == GL_TEXTURE_3D || cmd.args.blitFromTexture.dstTarget == GL_TEXTURE_2D_ARRAY) {
+                f->glFramebufferTextureLayer(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                                             cmd.args.blitFromTexture.dstTexture,
+                                             cmd.args.blitFromTexture.dstLevel,
+                                             cmd.args.blitFromTexture.dstLayer);
+            } else {
+                f->glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, cmd.args.blitFromTexture.dstTarget,
+                                          cmd.args.blitFromTexture.dstTexture, cmd.args.blitFromTexture.dstLevel);
+            }
+            f->glBlitFramebuffer(0, 0, cmd.args.blitFromTexture.w, cmd.args.blitFromTexture.h,
+                                 0, 0, cmd.args.blitFromTexture.w, cmd.args.blitFromTexture.h,
                                  GL_COLOR_BUFFER_BIT,
                                  GL_NEAREST); // Qt 5 used Nearest when resolving samples, stick to that
             f->glBindFramebuffer(GL_FRAMEBUFFER, ctx->defaultFramebufferObject());
@@ -4291,32 +4333,64 @@ void QRhiGles2::endPass(QRhiCommandBuffer *cb, QRhiResourceUpdateBatch *resource
 
     if (cbD->currentTarget->resourceType() == QRhiResource::TextureRenderTarget) {
         QGles2TextureRenderTarget *rtTex = QRHI_RES(QGles2TextureRenderTarget, cbD->currentTarget);
-        if (rtTex->m_desc.cbeginColorAttachments() != rtTex->m_desc.cendColorAttachments()) {
-            // handle only 1 color attachment and only (msaa) renderbuffer
-            const QRhiColorAttachment &colorAtt(*rtTex->m_desc.cbeginColorAttachments());
-            if (colorAtt.resolveTexture()) {
-                Q_ASSERT(colorAtt.renderBuffer());
+        for (auto it = rtTex->m_desc.cbeginColorAttachments(), itEnd = rtTex->m_desc.cendColorAttachments();
+             it != itEnd; ++it)
+        {
+            const QRhiColorAttachment &colorAtt(*it);
+            if (!colorAtt.resolveTexture())
+                continue;
+
+            QGles2Texture *resolveTexD = QRHI_RES(QGles2Texture, colorAtt.resolveTexture());
+            const QSize size = resolveTexD->pixelSize();
+            if (colorAtt.renderBuffer()) {
                 QGles2RenderBuffer *rbD = QRHI_RES(QGles2RenderBuffer, colorAtt.renderBuffer());
-                const QSize size = colorAtt.resolveTexture()->pixelSize();
                 if (rbD->pixelSize() != size) {
                     qWarning("Resolve source (%dx%d) and target (%dx%d) size does not match",
                              rbD->pixelSize().width(), rbD->pixelSize().height(), size.width(), size.height());
                 }
                 QGles2CommandBuffer::Command &cmd(cbD->commands.get());
                 cmd.cmd = QGles2CommandBuffer::Command::BlitFromRenderbuffer;
-                cmd.args.blitFromRb.renderbuffer = rbD->renderbuffer;
-                cmd.args.blitFromRb.w = size.width();
-                cmd.args.blitFromRb.h = size.height();
-                QGles2Texture *colorTexD = QRHI_RES(QGles2Texture, colorAtt.resolveTexture());
-                if (colorTexD->m_flags.testFlag(QRhiTexture::CubeMap))
-                    cmd.args.blitFromRb.target = GL_TEXTURE_CUBE_MAP_POSITIVE_X + uint(colorAtt.resolveLayer());
+                cmd.args.blitFromRenderbuffer.renderbuffer = rbD->renderbuffer;
+                cmd.args.blitFromRenderbuffer.w = size.width();
+                cmd.args.blitFromRenderbuffer.h = size.height();
+                if (resolveTexD->m_flags.testFlag(QRhiTexture::CubeMap))
+                    cmd.args.blitFromRenderbuffer.target = GL_TEXTURE_CUBE_MAP_POSITIVE_X + uint(colorAtt.resolveLayer());
+                else
+                    cmd.args.blitFromRenderbuffer.target = resolveTexD->target;
+                cmd.args.blitFromRenderbuffer.dstTexture = resolveTexD->texture;
+                cmd.args.blitFromRenderbuffer.dstLevel = colorAtt.resolveLevel();
+                const bool hasZ = resolveTexD->m_flags.testFlag(QRhiTexture::ThreeDimensional)
+                    || resolveTexD->m_flags.testFlag(QRhiTexture::TextureArray);
+                cmd.args.blitFromRenderbuffer.dstLayer = hasZ ? colorAtt.resolveLayer() : 0;
+            } else {
+                Q_ASSERT(colorAtt.texture());
+                QGles2Texture *texD = QRHI_RES(QGles2Texture, colorAtt.texture());
+                if (texD->pixelSize() != size) {
+                    qWarning("Resolve source (%dx%d) and target (%dx%d) size does not match",
+                             texD->pixelSize().width(), texD->pixelSize().height(), size.width(), size.height());
+                }
+                QGles2CommandBuffer::Command &cmd(cbD->commands.get());
+                cmd.cmd = QGles2CommandBuffer::Command::BlitFromTexture;
+                if (texD->m_flags.testFlag(QRhiTexture::CubeMap))
+                    cmd.args.blitFromTexture.srcTarget = GL_TEXTURE_CUBE_MAP_POSITIVE_X + uint(colorAtt.layer());
+                else
+                    cmd.args.blitFromTexture.srcTarget = texD->target;
+                cmd.args.blitFromTexture.srcTexture = texD->texture;
+                cmd.args.blitFromTexture.srcLevel = colorAtt.level();
+                cmd.args.blitFromTexture.srcLayer = 0;
+                if (texD->m_flags.testFlag(QRhiTexture::ThreeDimensional) || texD->m_flags.testFlag(QRhiTexture::TextureArray))
+                    cmd.args.blitFromTexture.srcLayer = colorAtt.layer();
+                cmd.args.blitFromTexture.w = size.width();
+                cmd.args.blitFromTexture.h = size.height();
+                if (resolveTexD->m_flags.testFlag(QRhiTexture::CubeMap))
+                    cmd.args.blitFromTexture.dstTarget = GL_TEXTURE_CUBE_MAP_POSITIVE_X + uint(colorAtt.resolveLayer());
                 else
-                    cmd.args.blitFromRb.target = colorTexD->target;
-                cmd.args.blitFromRb.texture = colorTexD->texture;
-                cmd.args.blitFromRb.dstLevel = colorAtt.resolveLevel();
-                const bool hasZ = colorTexD->m_flags.testFlag(QRhiTexture::ThreeDimensional)
-                    || colorTexD->m_flags.testFlag(QRhiTexture::TextureArray);
-                cmd.args.blitFromRb.dstLayer = hasZ ? colorAtt.resolveLayer() : 0;
+                    cmd.args.blitFromTexture.dstTarget = resolveTexD->target;
+                cmd.args.blitFromTexture.dstTexture = resolveTexD->texture;
+                cmd.args.blitFromTexture.dstLevel = colorAtt.resolveLevel();
+                cmd.args.blitFromTexture.dstLayer = 0;
+                if (resolveTexD->m_flags.testFlag(QRhiTexture::ThreeDimensional) || resolveTexD->m_flags.testFlag(QRhiTexture::TextureArray))
+                    cmd.args.blitFromTexture.dstLayer = colorAtt.resolveLayer();
             }
         }
     }
@@ -5235,7 +5309,7 @@ bool QGles2Texture::prepareCreate(QSize *adjustedSize)
     }
 
     target = isCube             ? GL_TEXTURE_CUBE_MAP
-            : m_sampleCount > 1 ? GL_TEXTURE_2D_MULTISAMPLE
+            : m_sampleCount > 1 ? (isArray ? GL_TEXTURE_2D_MULTISAMPLE_ARRAY : GL_TEXTURE_2D_MULTISAMPLE)
                                 : (is3D ? GL_TEXTURE_3D
                                         : (is1D ? (isArray ? GL_TEXTURE_1D_ARRAY : GL_TEXTURE_1D)
                                                 : (isArray ? GL_TEXTURE_2D_ARRAY : GL_TEXTURE_2D)));
diff --git a/src/gui/rhi/qrhigles2_p.h b/src/gui/rhi/qrhigles2_p.h
index fecb15698f..6db996d87d 100644
--- a/src/gui/rhi/qrhigles2_p.h
+++ b/src/gui/rhi/qrhigles2_p.h
@@ -331,6 +331,7 @@ struct QGles2CommandBuffer : public QRhiCommandBuffer
             CompressedImage,
             CompressedSubImage,
             BlitFromRenderbuffer,
+            BlitFromTexture,
             GenMip,
             BindComputePipeline,
             Dispatch,
@@ -494,10 +495,22 @@ struct QGles2CommandBuffer : public QRhiCommandBuffer
                 int w;
                 int h;
                 GLenum target;
-                GLuint texture;
+                GLuint dstTexture;
+                int dstLevel;
+                int dstLayer;
+            } blitFromRenderbuffer;
+            struct {
+                GLenum srcTarget;
+                GLuint srcTexture;
+                int srcLevel;
+                int srcLayer;
+                int w;
+                int h;
+                GLenum dstTarget;
+                GLuint dstTexture;
                 int dstLevel;
                 int dstLayer;
-            } blitFromRb;
+            } blitFromTexture;
             struct {
                 GLenum target;
                 GLuint texture;